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This section of the site presents publications of topical articles on heat supply and heat power engineering, as well as topical articles on construction, production and industrial equipment.

Hydraulic testing of pipelines.

Hydraulic testing of heating networks is carried out twice: first, the strength and density of the heating pipe is checked without equipment and fittings, then the entire heating pipe, which is ready for operation, with installed mud traps, valves, compensators and other equipment. Repeated testing is necessary because once the equipment and fittings are installed, it is more difficult to check the density and strength of the welds.

In cases where, when testing heat pipelines without equipment and fittings, there is a pressure drop according to the instruments, it means that the existing welds are loose (naturally, if there are no fistulas, cracks, etc. in the pipes themselves). Pressure drop when testing pipelines with installed equipment and fittings, perhaps indicates that in addition to the joints, gland seals or flange connections are also made with defects.

During the preliminary test, not only the welds, but also the walls of the pipelines are checked for density and strength, because It happens that pipes have cracks, fistulas and other factory defects. Tests of the installed pipeline must be carried out before installing thermal insulation. In addition, the pipeline should not be filled up or covered with engineering structures. When a pipeline is welded from seamless seamless pipes, it can be submitted for testing already insulated, but only with open welded joints.

During the final test, the connection points of individual sections (in cases where the heat pipeline is tested in parts), welds of mud traps and stuffing box expansion joints, equipment casings, and flange connections are subject to inspection. During inspection, the seals must be sealed and the section valves must be fully open.

The need for two tests of heating mains is also due to the fact that in long sections it is not possible to check the entire heating pipeline at one time. The trench would have to be left open for a long time. In this regard, individual sections of heating networks are tested before backfilling, as they are prepared. The length of the tested section depends on the construction time on individual sections of the route, on the availability of manual, hydraulic or mechanized presses, filling units, piston pumps, the power of the water source (river, pond, lake, water supply system), work conditions, terrain, etc. .

When hydraulic testing heating networks, the sequence of work is as follows:
- clean heating pipes;
- install pressure gauges, plugs and taps;
- connect water and hydraulic press;
- fill the pipelines with water to the required pressure;
- inspect heat pipelines and mark places where defects are found;
- eliminate defects;
- perform the second test;
- disconnect from the water supply and drain water from the pipes;
- remove pressure gauges and plugs.

To fill the pipelines with water and ensure good removal of air from the pipes, the water supply is connected to the bottom of the heating pipe. A person on duty must be posted near each air valve. First, only air flows through the vents, then an air-water mixture, and finally only water. When only water comes out, the tap is turned off. Next, the tap is periodically opened two or three more times to completely release the remaining air from the upper points. Before filling the heating network, all vents must be opened and drains closed.

The test is carried out with a pressure equal to the working pressure with a coefficient of 1.25. By working is meant the maximum pressure that can arise in a given area during operation.

In cases where a heat pipeline is tested without equipment and fittings, the pressure is raised to the design pressure and maintained for 10 minutes, while monitoring the pressure drop, then it is reduced to the working pressure and an inspection is carried out welded joints and tap the joints. The tests are considered satisfactory if there is no pressure drop, no leakage or sweating of the joints.

Tests with installed equipment and fittings are carried out with a holding period of 15 minutes, inspection of flange and welded joints, fittings and equipment, gland seals is carried out, after which the pressure is reduced to operating pressure. The tests are considered satisfactory if within 2 hours the pressure drop does not exceed 10%. The test pressure not only checks the tightness, but also the strength of the equipment and pipeline.

After testing, water must be completely removed from the pipes. As a rule, test water does not undergo special preparation and can reduce the quality of supply water and cause corrosion of the internal surfaces of pipes.

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Date of introduction: 02/01/2000

Receiving authority: Department of Development Strategy and Scientific and Technical Policy of RAO "UES of Russia"

DESIGNED by Open joint stock company"Company for setting up, improving technology and operating power plants and networks of ORGRES"

Performers R.M.Sokolov, E.M.Shmyrev, G.I.Tretilevich, Yu.Yu.Shtromberg, V.N.Osmakov

AGREED with Gosgortekhnadzor of Russia on December 21, 1999 (Letter No. 12-06/1117)

Head of the Department for Boiler Inspection and Supervision of Lifting Structures B.S. Kotelnikov

APPROVED by the Department of Development Strategy and Scientific and Technical Policy of RAO "UES of Russia" 09.12.99

First Deputy Chief A.P. Bersenev

INTRODUCED FOR THE FIRST TIME

Real Standard instructions establishes the procedure and methods for periodic technical inspection during the operation of pipelines of heating networks belonging to categories IV and III according to the classification of the Rules of the State Mining and Technical Supervision of Russia.

The standard instructions are compiled on the basis of , , , , , , and other normative and technical documentation related to the issues of operation, control and technical inspection of heating network pipelines.

The standard instructions are drawn up in accordance with the Federal Law "On industrial safety hazardous production facilities" and Resolution No. 45 of June 25, 1999 of the Gosgortekhnadzor of Russia.

The standard instructions are intended for organizations (enterprises) that own pipelines operating heating networks, as part of joint-stock companies and joint-stock power plants and are aimed at increasing the operational reliability and technical level of operation of heating network pipelines.

Based on the Standard Instructions, organizations (enterprises) that own pipelines operating heating networks can draw up local instructions for periodic technical examination during the operation of heating network pipelines belonging to categories IV and III according to the classification of the Rules, taking into account technical features and specific operating conditions.

Organizations (enterprises) performing technical inspection of pipelines of heating networks must have the appropriate permits (licenses) from the Gosgortekhnadzor bodies of Russia.

1. GENERAL PROVISIONS

1.1. Periodic technical inspection of heating network pipelines is carried out to verify technical condition pipelines, their compliance with the requirements of the Rules and determining the possibility of their further operation in accordance with. For terms and definitions, see Appendix 1.

1.3. When determining the category and group of the pipeline, the operating parameters of the transported medium for the supply and return pipelines of water heating networks should be taken to be the highest possible pressure and maximum temperature of water in the supply pipeline, taking into account the operation of pumping substations on the route and the terrain.

For pipelines of steam heating networks, the operating parameters should be taken as the parameters specified in clause 1.1.4, c, d of the Rules.

1.4. The category of a pipeline, determined by the operating parameters of the transported medium at its inlet (in the absence of devices on it that change these parameters), applies to the entire pipeline, regardless of its length, and must be indicated in the design documentation and pipeline passport.

1.5. Pipelines of heating networks, which are subject to the Rules *, during operation must be subject to the following types of technical examination: external inspection and hydraulic testing.

* Rules (clause 1.1.1) "...establish requirements for the design, construction, materials, manufacture, installation, repair and operation of pipelines transporting water vapor with an operating pressure of more than 0.07 MPa (0.7 kgf/cm) or hot water with a temperature above 115 ° C."

The rules (clause 1.1.2) do not apply to "e) pipelines of category I with an outer diameter of less than 51 mm and pipelines of categories II, III and IV with an outer diameter of less than 76 mm; + j) pipelines made of non-metallic materials."

1.6. External inspection of heating network pipelines during technical inspection can be carried out without removing the insulation or with removing the insulation.

External inspection of pipelines, carried out without removing the insulation, is aimed at checking: the absence of visible leaks from the pipeline and pinching of the pipeline in expansion joints, in places where the pipeline passes through the walls of chambers, platforms, etc.; states of moving and fixed supports.

External inspection of pipelines, carried out with removal of insulation, is aimed at identifying changes in the shape of the pipeline, surface defects in the base metal of the pipeline and welded joints formed during operation (cracks of all types and directions, corrosive wear of surfaces, etc.), and should include visual and measuring control. The decision on the need to remove insulation and carry out measurement control, as well as its volume, can be made by an inspector of the Gosgortekhnadzor of Russia, a specialist from an organization that has a permit (license) from the Gosgortekhnadzor bodies of Russia to conduct a technical inspection of pipelines, or a person responsible for the good condition and safe operation of the pipeline.

1.7. Technical inspection of heating network pipelines must be carried out by a person responsible for the good condition and safe operation of pipelines within the following periods:

external inspection of pipelines of all categories during operation - at least once a year;

external inspection and hydraulic testing of pipelines that are not subject to registration with the Gosgortekhnadzor of Russia * , - before putting into operation after installation, repairs related to welding, as well as when starting up pipelines after they have been in a state of conservation for more than two years.

* The rules (clause 5.1.2) establish that: “Pipelines of category I with a nominal bore of more than 70 mm, pipelines of categories II and III with a nominal bore of more than 100 mm, as well as pipelines of category IV located within the buildings of thermal power plants and boiler houses ", with a nominal bore of more than 100 mm must be registered before putting into operation with the Gosgortekhnadzor of Russia. Other pipelines to which these Rules apply are subject to registration at the enterprise (organization) that is the owner of the pipeline."

1.8. Heat network pipelines registered with the Gosgortekhnadzor authorities of Russia must be subject to:

external inspection and hydraulic testing before launching a newly installed pipeline (external inspection in this case must be carried out before applying insulation and must include visual and measuring control), after repair of the pipeline associated with welding, as well as when starting up the pipeline after being in a state of preservation for more than two years (carried out by an inspector of the Gosgortekhnadzor of Russia);

external inspection at least once every three years (carried out by a specialist from an organization that has a permit (license) from the Gosgortechnadzor authorities of Russia to conduct a technical inspection of steam and hot water).

1.9. Annual external inspection during operation of heating network pipelines laid in places accessible for inspection (for above-ground installation, as well as in collectors, tunnels, passage channels, panel penetrations) must be carried out without removing the insulation. If a leak or steaming of the pipeline is detected, destruction of the insulation, or abnormal displacements of the pipeline, the insulation must be removed, and the pipeline must be subjected to an external inspection, including visual and (by the decision of the person responsible for the good condition and safe operation of the pipeline) measurement control.

1.10. Annual external inspection during operation of heating network pipelines in places inaccessible for inspection (when laid in non-passable channels, channelless installation) should be carried out by inspecting pipelines within chambers and manholes without removing the insulation. External inspection of such pipelines, including visual and (by decision of the person responsible for the good condition and safe operation of the pipeline) measurement control, with opening of the soil and removal of insulation, should be carried out when a leak or steam is detected from the pipeline, abnormal displacements of the pipeline, destruction or wetting of the insulation and etc. To detect defects in pipelines by indirect methods, modern methods of non-destructive monitoring of the condition of pipelines of heating networks should be used: infrared technology, acoustic and ultrasonic leak detectors, methods of correlation*, acoustic emission**, etc.

* The correlation method (correlation - “relationship”) is based on determining the difference in the time of arrival of the acoustic signal caused by water leakage from the pipeline to two measurement points. The correlator calculates the distance between the leak location and one of the measurement points and displays it graphically or digitally (in meters).

** The acoustic emission method is based on the registration and analysis of acoustic signals accompanying the origin and development of micro- and macrodefects in a controlled pipeline under the influence of various types loads

1.11. For underground pipelines of heating networks laid using insulating structures of high factory readiness (for example, pipelines with insulation made of polyurethane foam and a shell pipe made of high-density polyethylene, equipped with an operational remote monitoring system - ODK, signaling damage and the presence of moisture in the insulation, as well as pipelines with other types of thermal insulation structures that are not inferior to the above structure in terms of operational properties), for which the manufacturer and the construction and installation organization that lays insulated pipes and seals butt joints guarantee the tightness of the insulating structure, an annual external inspection during operation may not be produced. In this case, during operation, continuous monitoring of the sensor readings of the UEC system must be carried out. External inspection of such pipelines with opening of the soil and removal of insulation, including visual and measuring control, should be carried out only upon receipt of sensor signals indicating a violation normal operation insulation structure on certain sections of pipelines (humidification, etc.).

1.12. External inspection of pipelines during operation, including visual and measuring control, must be carried out in accordance with.

1.13. Pipelines, regardless of the installation method and the type of thermal insulation structure, that have served their designated service life (for heating network pipelines - “standard service life” *), which must be indicated in the design documentation and pipeline passport, must undergo technical diagnostics or must be taken out of service . Technical diagnostics must be performed by an organization that has a permit (license) from the Gosgortekhnadzor of Russia to perform this work.

* The standard service life of heating network pipelines is adopted according to the depreciation rates established in the current document “On uniform standards of depreciation for the complete restoration of fixed assets of the national economy of the USSR” (Resolution of the USSR Council of Ministers of October 22, 1990 N 1072). For steel pipelines of heating networks (code 30121), this norm is 4% of the book value, which corresponds to 25 years of operation. This period should be accepted by designers during feasibility studies of projects.

1.14. During a technical inspection of pipelines of heating networks, if it is carried out by an inspector of the Gosgortekhnadzor of Russia or a specialist from another organization, the presence of a person responsible for the good condition and safe operation of pipelines on the part of the organization (enterprise) that owns the pipeline is required.

1.15. Before technical examination, the pipeline must be securely disconnected from existing pipelines and equipment - clause 5.3 and clause 4.2.

1.16. Technical inspection of heating network pipelines must be carried out in the following sequence:

a) passport check ( technical documentation) pipeline;

b) carrying out an external inspection of the pipeline;

c) carrying out hydraulic testing of the pipeline.

2. PREPARATION OF HEATING NETWORKS PIPELINES FOR EXTERNAL INSPECTION DURING PERIODIC TECHNICAL INSPECTION

2.1. The preparation of heating network pipelines for external inspection is carried out by the organization (enterprise) that owns the pipeline and operates the heating network.

2.2. Pipelines of heating networks, subject to external inspection, including visual and measuring control, must be taken out of service, cooled to a temperature not exceeding 40 ° C, drained, disconnected from adjacent pipelines, and thermal insulation, which prevents monitoring of the technical condition of the metal of pipes and welded joints, must be partially or completely removed in places specified by the technical inspection work program.

2.3. To carry out work on opening underground pipelines of heating networks (opening soil and channels, removing insulation), as well as removing insulation from pipelines laid above ground and in tunnels (passage channels), during periodic technical inspections in the organization (enterprise) that owns the pipelines, operating heating networks, a commission must be organized under the chairmanship of a person responsible for the good condition and safe operation of pipelines, appointed by order of the organization (enterprise).

2.4. Opening of pipelines for external inspection in underground heating networks laid in non-through channels and without channels should be carried out primarily in places where, according to and, there are signs (criteria) of danger of external corrosion of pipelines.

For underground heating networks laid in channels, the signs (criteria) of the danger of external corrosion of pipelines are:

the presence of water in the channel or the passage of the channel with soil, when water or soil reaches the insulating structure of the pipeline;

moistening of the thermal insulation structure of the pipeline (detected during operation) with drip moisture from the channel slab, which reaches the surface of the pipeline, or moisture flowing down the panel support.

For underground heating networks laid without ducts, the signs (criteria) of the danger of external corrosion of pipelines are:

corrosive aggressiveness of soils, rated as "high" , , ;

dangerous influence of constant* and alternating** stray currents on pipelines.

* A sign of the dangerous influence of constant stray currents on pipelines of underground heating networks should be considered the presence of an alternating sign (alternating zone) or time-varying displacement of the potential difference between the pipelines of heating networks and the reference electrode from a stationary potential towards positive values ​​(anode zone).

** A sign of the dangerous influence of alternating stray currents on the pipelines of underground heating networks should be considered a shift in the average value of the potential difference between the pipelines of the heating networks and the copper sulfate reference electrode in the negative direction by at least 10 mV compared to the potential difference measured in the absence of the influence of alternating current.

2.5. In addition to those sections of pipelines where there are signs (criteria) of dangerous external corrosion (see clause 2.4 of this Standard Instruction), in underground channel and non-channel installations, opening of heating network pipelines for external inspection during technical inspection should also be carried out mainly in the unfavorable places indicated below where processes of external corrosion of pipelines may occur:

near places where corrosion damage to pipelines was observed during operation;

in areas located near sewer and water supply lines or at intersections with these structures;

in places where there are increased heat losses;

in those places where coolant leaks were detected based on the results of infrared photography.

2.6. The organization (enterprise) that owns the pipeline operating heating networks must have a pipeline passport (with a diagram of the heating network), which must systematically indicate: flooded sections of pipelines; areas where pipelines were re-routed; places where corrosion and other damage to pipelines was observed; places where excavations were carried out or pipelines were opened for external inspection. The diagram should include rail tracks of electrified transport, adjacent metal underground communications, locations of electrochemical protection installations on pipelines of heating networks and adjacent underground metal structures.

2.7. When carrying out work on opening pipelines for technical inspection, an incidental inspection and assessment of the condition of building and insulating structures must be carried out in accordance with.

3. REQUIREMENTS FOR DEVICES AND TOOLS DURING EXTERNAL INSPECTION, VISUAL AND MEASURING CONTROL OF HEAT NETWORKS PIPELINES DURING PERIODIC TECHNICAL INSPECTION

3.1. Visual inspection of the pipeline and welded joints is carried out with the naked eye or using optical instruments (magnifiers, visual optical instruments for monitoring remote and hidden objects).

3.2. To measure the shape and dimensions of the pipeline and welded joints, as well as surface defects, serviceable instruments that have passed metrological verification and have stamps with an unexpired verification date must be used. Supervision over the condition of measuring instruments should be carried out by the metrological department of the organization (enterprise) - the owner.

3.3. The measurement error during measurement control should not exceed the values ​​​​specified in.

4. REQUIREMENTS FOR PERSONNEL CONDUCTING PERIODIC TECHNICAL INSPECTION OF HEAT NETWORKS PIPELINES

4.1. Work on visual and measurement control of pipelines of heating networks during external inspection must be carried out by specialists (engineering and technical workers) who have the necessary general education, theoretical and practical training in visual and measurement control, who have been certified for the right to perform control work in the manner established by the Gosgortekhnadzor of Russia .

4.2. Theoretical and practical training of specialists and inspectors should be carried out at special courses at training and certification centers, training centers or at the place of work in non-destructive testing departments in accordance with the program given in.

5. PROCEDURE AND METHODS FOR EXTERNAL INSPECTION, VISUAL AND MEASURING CONTROL OF HEAT NETWORKS PIPELINES DURING PERIODIC TECHNICAL INSPECTION; RESULTS EVALUATION

5.1. Visual inspection of the base metal of the heating network pipeline and welded joints at the stage of periodic technical inspection should be carried out in order to confirm the absence of surface damage caused by the operating conditions of the pipeline.

Measurement control of the base metal of the heating network pipeline and welded joints at the stage of periodic technical inspection must be carried out in order to confirm the acceptability of damage to the base metal of the pipeline and welded joints identified during visual inspection, as well as compliance of the geometric dimensions of the pipeline and welded joints with the requirements of working drawings, technical specifications, standards and passports.

5.2. When conducting an external inspection of a heating network pipeline, the following must be checked:

correspondence executive scheme given in the pipeline passport, the actual state of the controlled pipeline;

presence and compliance of types of pipeline supports with the installation and assembly drawing, their serviceability; the diagram must indicate the distances between the points of attachment of the supports to the pipeline and the nearest welds or bends;

absence of pipeline pinching when passing through the walls of chambers, near columns and frame trusses;

presence and serviceability of drains;

insulation state;

5.4. During visual and measurement inspection carried out during external inspection of pipelines of heating networks during technical inspection, changes in the shape of pipelines should be detected, as well as surface defects in the base metal of pipelines and welded joints formed during operation (corrosive wear of surfaces, cracks of all types and directions , deformation of pipelines, etc.).

5.5. Before carrying out visual and measuring inspection, the surface of the pipeline or welded joint in the inspection zone must be cleaned to bare metal from corrosion products, scale, dirt, paint, splashes of molten metal and other contaminants that interfere with inspection.

5.6. Visual and measuring control of the metal condition of pipes and welded joints during periodic technical inspection of heating network pipelines must be carried out in accordance with the "Technological maps of visual and measuring control during external inspection of heating network pipelines" (Appendix 2), which should be developed as part of the "Periodic technical examination of pipelines of heating networks", which must be developed by the organization (enterprise) - the owner of the pipeline operating the pipelines of heating networks, or a special organization that has the appropriate license issued by the Gosgortekhnadzor of Russia. Technological maps must indicate the locations of control on a specific pipeline, control schemes, means of measuring the controlled parameter, quality assessment standards, and forms for recording the results of measurement control.

5.7. Visual inspection should generally be performed with the naked eye or with a magnifying glass.

5.8. Visual and measurement control during external inspection of the pipeline must be carried out before testing the pipeline (and welded joints) by other methods of non-destructive testing of magnetic particle flaw detection (before hydraulic testing, before ultrasonic testing, etc.). All measurements must be made after visual inspection or in parallel with it.

5.9. If accessible for inspection, visual and measuring inspection of the heating network pipeline (and welded joints on it) should be carried out both from the outside and from the inside.

Inspection of the heating network pipeline from the inside must be carried out during repair work on the pipeline (replacing pipeline sections, disassembling flange connections, changing pipeline routing, etc.).

5.10. When visually inspecting the condition of the base metal of the heating network pipeline and welded joints, the absence of:

mechanical damage to the base metal of the pipeline and the deposited metal of welded joints;

cracks and other surface defects formed during operation;

corrosion damage to pipeline metal surfaces and welded joints (corrosive wear);

deformed sections of the pipeline (warping, sagging and other deviations from the original shape).

5.11. When measuring the condition of the base metal of the heating network pipeline and welded joints, the following must be determined:

dimensions of mechanical damage to the base metal of the pipeline and welded joints, including the length, width and depth of dents, bulges, etc.;

ovality of cylindrical elements, including pipe bends, straightness (deflection) of the pipeline generatrix;

actual pipeline wall thickness, depth of corrosion damage and pits, dimensions of corrosion damage zones.

5.12. Measurements of the actual thickness of the pipeline wall must be carried out using the ultrasonic method, using previously marked points.

Ultrasonic thickness gauges that meet the requirements of GOST 28702-90 must be used for measurements.

5.13. Sections of the pipeline in which corrosion damage to the metal was detected during inspection must be subject to additional visual and measuring control during further operation, the frequency and volume of which must be determined by the person responsible for the good condition and safe operation of the pipeline. In this case, the necessary measures must be taken to identify the causes of metal corrosion and eliminate them.

5.14. Unacceptable surface defects identified during visual and measurement inspection must be corrected before testing by other non-destructive methods (if any).

5.15. Evaluation of the results of visual and measuring control of the metal condition of pipes and welded joints during the technical inspection of pipelines of heating networks must be carried out in accordance with the standards given in the Rules and other normative and technical documentation.

Standards for assessing quality during visual and measurement control must be provided in the production control documentation for visual and measurement control of specific pipelines.

5.16. For pipelines of heating networks, the assessment of the results of measurement control should be taken based on the proportion of reduction in the initial (calculated) wall thickness.

Sections of the pipeline in which measurement control revealed a decrease in the original (calculated) pipeline wall thickness by 20% or more are subject to replacement. To make a decision on replacement, the person responsible for the good condition and safe operation of the pipeline must perform a verification calculation for the strength of the section of the pipeline where wall thinning was detected, taking into account the requirements of clause 2.1.2 of the Rules.

5.17. The results of visual and measurement monitoring of the internal surface of heating network pipelines should be assessed taking into account the intensity of the internal corrosion process (Table 2), determined by the “internal corrosion indicators” installed in heating networks. Table 2 is based on the corrosion rate (permeability) (mm/year), .

table 2

Assessment of the intensity of internal corrosion

The value should be determined by comparing the corrosion rate (permeability) data obtained from current measurements with the data from the previous measurement control, taking into account the time elapsed between the previous and current measurements. The method for determining the value is given in.

The intensity of corrosion corresponding to group 1 is considered safe.

If the intensity of corrosion corresponds to group 2, the causes of corrosion must be analyzed and measures must be developed to eliminate them.

If the corrosion intensity corresponds to groups 3 and 4, operation of the pipeline should be prohibited until the causes causing intense internal corrosion are eliminated. The decision to prohibit further operation of the pipeline is made by the person who inspected the pipeline.

5.18. Assessment of the quality of welded joints of heating network pipelines should be carried out in accordance with, , and.

6. REGISTRATION OF RESULTS OF VISUAL AND MEASURING CONTROL DURING EXTERNAL INSPECTION OF HEAT NETWORKS PIPELINES DURING PERIODIC TECHNICAL INSPECTION

6.1. The results of visual and measurement control during external inspection at the stage of technical inspection of heating network pipelines during operation must be recorded in the accounting (log book and registration of the results of visual and measurement control - Appendix 3) and reporting documentation drawn up in accordance with, and entered into the passport pipeline.

7. HYDRAULIC TESTING OF HEATING NETWORKS PIPELINES DURING PERIODIC TECHNICAL INSPECTION

7.1. During periodic technical inspection, heating network pipelines must be subjected to hydraulic testing in order to check the strength and density of pipelines and their elements (see Appendix 1), including all welded and other connections.

A hydraulic test is carried out after an external inspection, visual and measuring (if any) control of the pipeline.

7.2. The minimum test pressure value during hydraulic testing of heating network pipelines should be 1.25 working pressure.

The operating pressure value for heating network pipelines in accordance with clause 4.12.31 must be established by the technical manager of the organization operating the heating networks in accordance with the requirements of clause 1.1.4 of the Rules.

7.3. The maximum value of the test pressure is set in accordance with the requirements of clause 4.12.4 of the Rules, taking into account the maximum loads that can be assumed by the fixed supports.

In each specific case, the value of the test pressure must be established according to the technical manager of the organization operating the heating networks.

7.4. Supply and return pipelines of heating networks must be tested separately.

7.5. The hydraulic test must be carried out in the following order:

the tested section of the pipeline is disconnected from the existing heating network;

using a pressure gauge located at the highest point of the section of the pipeline being tested, after filling the latter with water and releasing air, the test pressure is established; the pressure in the pipeline should be increased gradually; the rate of pressure rise must be indicated in the technical documentation for the manufacture of the pipeline;

the pipeline is maintained under test pressure for at least 10 minutes, after which this pressure is gradually reduced to the operating value, at which a thorough inspection of the pipeline along its entire length is carried out.

7.6. For hydraulic testing of the pipeline, water with a temperature not lower than plus 5 and not higher than plus 40 ° C should be used.

Hydraulic testing of the pipeline during periodic technical inspection must be carried out at positive ambient temperatures.

7.7. Pressure measurement during hydraulic testing of a pipeline must be carried out using two pressure gauges, one of which must be a control one. In this case, pressure gauges must be of the same type, with the same accuracy class, measurement limit and division value.

When testing a pipeline, spring pressure gauges that have been verified in the prescribed manner should be used. The use of pressure gauges with expired verification dates is not permitted. Spring pressure gauges must have an accuracy class of 1.5, a body diameter of at least 150 mm and a scale for a nominal pressure of about 4/3 of the measured pressure.

7.8. The pipeline and its elements are considered to have passed the hydraulic test if the following are not detected: leaks, sweating in welded joints and base metal, visible residual deformations, cracks and signs of rupture.

7.9. Unacceptable defects discovered during the hydraulic test must be eliminated, followed by inspection of the corrected areas.

The technology for correcting defects and the control procedure are established by production and technical documentation developed in accordance with the Rules and other normative and technical documentation.

Correction of defects in the same area of ​​a welded joint may be performed no more than three times.

7.10. The results of the hydraulic testing of the pipeline are documented in a report, the recommended form of which is given in Appendix 6.

8. REQUIREMENTS FOR TECHNICAL DOCUMENTATION FOR PERIODIC TECHNICAL INSPECTION OF HEAT NETWORKS PIPELINES

8.1. The results of the periodic technical inspection of the heating network pipeline and the conclusion on the possibility of its further operation, indicating the permitted pressure and the timing of the next technical inspection, must be recorded in the pipeline passport by the person who carried out the inspection (the person responsible for the good condition and safe operation of the pipeline; a specialist from an organization with a permit (license) of the Gosgortekhnadzor bodies of Russia to conduct technical inspection of pipelines; inspector of the Gosgortekhnadzor of Russia).

8.2. If, during the inspection of the pipeline, it turns out that it has serious defects that raise doubts about its strength, then further operation of the pipeline should be prohibited.

The decision to terminate the operation of the pipeline is made by the person who conducted the survey, about which he makes an appropriate entry with justification in the pipeline passport, and also gives an order to terminate further operation of the pipeline to the technical manager of the organization (enterprise) operating the heating networks.

The heating network pipeline is taken out of operation by order of the technical manager of the organization (enterprise) operating the heating networks, in agreement with the dispatcher.

9. SAFETY MEASURES WHEN CARRYING OUT PERIODIC TECHNICAL INSPECTION OF HEAT NETWORKS PIPELINES

9.1. When carrying out work on periodic technical inspection of heating network pipelines (external inspection, visual and measurement control, hydraulic testing, preparatory work), the requirements must be observed.

9.2. Sanitary and hygienic working conditions at those workplaces where control is carried out must meet the requirements.

9.3. At those workplaces where control is carried out, electrical safety conditions must be ensured in accordance with the requirements.

9.4. Fire safety measures must be carried out in accordance with the requirements and.

9.5. Work on the preparation and conduct of periodic technical inspection of heating network pipelines must be carried out in accordance with written approval orders.

9.6. Before being allowed to carry out work on preparation for periodic technical inspection of heating network pipelines, all persons involved in the work must undergo appropriate safety training and be registered in a special journal. The briefing should be carried out within the time limits established by the order of the organization (enterprise) that owns the pipeline and operates the heating networks.

9.7. To carry out external inspection work (visual and measurement control), the convenience of approach for persons performing the external inspection must be ensured; conditions for the safe conduct of work must be created at the place of inspection and control; when working at height, scaffolding, fencing, and scaffolding must be equipped; Workplaces must be provided with the ability to connect local lighting lamps with a voltage of 12 V.

9.8. If work is performed at height or in cramped conditions, personnel must undergo additional safety training in accordance with the regulations in force in the organization (enterprise) operating heating networks.

9.9. In order to prevent eye fatigue and improve the quality of visual and measurement control, it is recommended to take ten-minute breaks every hour of work.

9.10. The specialists carrying out control must be provided with headgear and special clothing in accordance with industry standards of the Ministry of Fuel and Energy of the Russian Federation.

Annex 1

TERMS AND DEFINITIONS

Term	Definition, NTD
Pipeline owner	The organization (enterprise) on whose balance sheet the pipeline is located and whose administration bears legal and criminal responsibility for its safe operation
Defect	Each individual non-compliance of products with established requirements,
Durability	The property of an object to maintain an operational state until a limit state occurs with an installed maintenance and repair system
Permissible wall thickness	The wall thickness at which the part can operate at the design parameters during the design life; it is a criterion for determining sufficient actual wall thicknesses
Technical condition monitoring (monitoring)	Checking the compliance of object parameter values ​​with the requirements of technical documentation and determining on this basis one of the specified types of technical condition at a given time. Note. Types of technical condition are, for example, serviceable, operational, faulty, inoperative, etc. depending on the parameter values ​​at a given time
Limit state criterion	A sign (set of signs) of the limiting state of an object, established by normative, technical and (or) design (project) documentation
Reliability	The property of an object to maintain over time, within established limits, the values ​​of all parameters characterizing the ability to perform the required functions in given modes and conditions of use, maintenance, storage and transportation. Note. Reliability is a complex property, which, depending on the purpose of the object and the conditions of its use, may include non-failure operation, durability, maintainability and storability or certain combinations of these properties
Assigned resource	The total operating time, upon reaching which the operation of the object must be stopped, regardless of its technical condition
Designated service life	The calendar duration of operation, upon reaching which the operation of the facility must be terminated, regardless of its technical condition
Operating time	Duration or scope of work of the facility Note. The operating time can be either a continuous value (working hours in hours, mileage, etc.) or an integer value (number of work cycles, starts, etc.)
Fixed support	A support that fixes individual points of the pipeline and absorbs the forces arising in it due to temperature deformations and internal pressure,
Weld joint discontinuity	A generalized name for all violations of the continuity and shape of a welded joint (cracks, lack of penetration, lack of fusion, inclusions, etc.)
Base metal	Metal of parts connected by welding
Residual resource	The total operating time of an object from the moment of monitoring its technical condition until the transition to the limit state Note. Similarly, the concepts of residual time to failure, residual service life and residual shelf life are introduced.
Refusal	An event consisting in a violation of the operational state of an object
Damage	An event consisting of a violation of the serviceable state of an object while maintaining the serviceable state
Movable support	A support that takes the weight of the pipeline and provides it with free movement during temperature deformations,
Limit state	The condition of an object in which its further operation is unacceptable or impractical, or restoring its working condition is impossible or impractical
Test pressure	Excess pressure at which a hydraulic test of a pipeline or its fitting (part) must be carried out for strength and density
Operating pressure in the pipeline element	Maximum excess pressure at the inlet to a pipeline element, determined from the operating pressure of the pipeline, taking into account resistance and hydrostatic pressure
Operating parameters of the transported medium	For supply and return pipelines of water heating networks - the highest possible pressure and maximum temperature of water in the supply pipeline, taking into account the operation of pumping substations along the route and the terrain. For pipelines of steam heating networks - parameters specified in clause 1.1.4, c, d
Allowed pressure	The maximum permissible excess pressure in the pipeline or its fitting, established based on the results of a technical examination or a control strength calculation
Estimated ambient temperature	Maximum temperature of hot water or steam in the pipeline or its fitting
Design wall thickness	The wall thickness theoretically required to ensure the strength of a part when exposed to internal or external pressure
Design pressure	The maximum excess pressure in the design part for which strength calculations are made when justifying the main dimensions that ensure operation during the design life Pressure taken when calculating the strength of a pipeline element
Repair	A set of operations to restore the serviceability and performance of products and restore the resources of products or their components
Resource	The total operating time of an object from the beginning of its operation or its resumption after repair until the transition to the limit state
Welded joint	Permanent connection of parts made by welding and including a seam and a heat-affected zone
Weld seam	A section of a welded joint formed as a result of crystallization of the molten metal, plastic deformation during pressure welding, or a combination of crystallization and deformation
Life time	Calendar duration of operation from the start of operation of the facility or its resumption after repair until transition to the limit state
Heat network	A set of devices intended for the transfer and distribution of thermal energy to consumers
Technical diagnostics (diagnosis)	Determination of the technical condition of the object. Notes: 1. Tasks technical diagnostics are: technical condition monitoring; searching for a location and determining the causes of failure (malfunction); forecasting technical condition. 2. The term “technical diagnostics” is used in the names and definitions of concepts when the technical diagnostic tasks being solved are equivalent or the main task is to find the location and determine the causes of the failure (malfunction). The term “technical condition monitoring” is used when the main task of technical diagnostics is to determine the type of technical condition
Actual wall thickness	Wall thickness measured at a specific area of ​​a part that determines the operating parameters during manufacture or in operation
Pipe element	An assembly unit of a hot water or steam pipeline designed to perform one of the main functions of the pipeline (for example, a straight section, elbow, tee, conical transition, flange, etc.)

Appendix 2

REQUIREMENTS FOR THE CONTENT OF "TECHNOLOGICAL MAP FOR VISUAL AND MEASURING CONTROL DURING EXTERNAL INSPECTION OF HEATING NETWORK PIPELINES"

The technological map of visual and measurement control must contain the following information:

1. Name of the organization (enterprise) and service performing visual and measurement control.

2. Card code.

3. Name of the controlled pipeline indicating the standard or specifications for manufacturing (installation, repair).

4. Name of the control stage (control during technical examination, control of defect correction, etc.).

5. Requirements for introducing an object into control mode (illumination of the object).

6. List of controlled parameters indicating standard indicators for visual inspection.

Note. When developing a map, one should be guided by the requirements of other normative and technical documentation regulating the requirements for visual and measurement control, including quality assessment standards, and working design documentation for the pipeline (welded joint).

Appendix 3

REQUIREMENTS FOR THE CONTENT OF THE "JOURNAL OF WORK ACCOUNTING AND REGISTRATION OF THE RESULTS OF VISUAL AND MEASURING CONTROL DURING EXTERNAL INSPECTION OF A HEATING NETWORK PIPELINE"

The Log Book must indicate:

1. Name and type of controlled object, its number and code.

2. Location and, if necessary, dimensions of controlled areas at the control object.

3. Conditions for carrying out control.

4. Production control document, its number.

5. Method of optical inspection of an object and the instruments used.

6. Method of measurement control and used devices (tools).

7. Brand and batch number of the material being tested (pipeline).

8. Main characteristics of defects identified during inspection (shape, size, location or orientation relative to the basic axes or surfaces of the test object).

9. Name or code of the regulatory and technical documentation according to which the quality assessment was carried out.

Note. In clause 5, either B (visual) or VO (visual-optical) is indicated. The visual-optical flaw detection method is performed using optical instruments (loupes, endoscopes, etc.).

Appendix 4

(enterprise, organization)

ACT N_____ dated______ VISUAL AND MEASURING CONTROL AND EXTERNAL INSPECTION OF THE HEATING NETWORK PIPELINE (recommended form)

1. In accordance with the work order (application)
				number
completed
	visual, measuring
control
	name and dimensions of the controlled object, number of technical documentation, specifications,
drawing, control object number
The control was carried out according to
		name and/or code of PKD
with quality assessment according to standards
			name and/or code of the NTD
2. During inspection, the following defects were revealed
					characteristics of defects,
shape, size, location or orientation for specific objects
3. Conclusion based on the results of visual and measurement control

Appendix 5

REQUIREMENTS FOR REGISTRATION
"SIZE PROTOCOL _____________"
	an object

Appendix 6

ACT FOR HYDRAULIC TESTING OF HEATING NETWORK PIPELINE DURING PERIODIC TECHNICAL INSPECTION (recommended form)

G._________________

"______"________________G.

An object
We, the undersigned,
				name of the organization (enterprise),
position, full name
have drawn up this act in that in the area from cell N________ to cell N_______ routes__________________________________________________________________________
						length		m
pipeline name
A hydraulic test of the pipeline was carried out with test pressure _____ MPa (kgf/cm) for _________ minutes, followed by inspection at a pressure of ____ MPa (kgf/cm). It was discovered
The pipeline was completed according to the project
Drawings N
Conclusion

List of used literature

1. Federal Law "On Industrial Safety of Hazardous Production Facilities". Adopted by the State Duma on June 20, 1997 (3588).

2. Resolution of the Federal Mining and Industrial Supervision of Russia (Gosgortekhnadzor of Russia) dated June 25, 1999 N 45 “On compliance with the requirements of the Rules and Safety Standards for the operation of thermal power equipment by enterprises and organizations of RAO UES of Russia.”

3. GOST 9.602-89. one system protection against corrosion and aging. Underground structures. General requirements for corrosion protection.

4. GOST 15467-79. Product quality management. Basic concepts. Terms and Definitions.

5. GOST 18322-78. Equipment maintenance and repair system. Terms and Definitions.

6. GOST 20911-89. Technical diagnostics. Terms and Definitions.

7. GOST 23172-78. Stationary boilers. Terms and Definitions.

8. GOST 23479-79. Non-destructive testing. Optical view methods. General requirements.

9. GOST 27.002-89. Reliability in technology. Basic concepts. Terms and Definitions.

10. GOST 28702-90. Non-destructive testing. Ultrasonic thickness gauges. General technical requirements.

11. SN 245-71. Sanitary standards for the design of industrial enterprises. - M.: Publishing House of Construction Literature, 1972.

12. SNiP 2.04.07-86*. Heating network. - M.: Ministry of Construction of Russia, 1994.

13. SNiP 3.05.03-85. Heating network. - M.: CITP Gosstroy USSR, 1986.

14. Rules and regulations for the protection of heating network pipelines from electrochemical corrosion: RD 34.20.520-96*. - M.: SPO ORGRES, 1998.

* In the territory Russian Federation RD 153-34.0-20.518-2003 "Standard instructions for the protection of heating network pipelines from external corrosion" is valid

15. Fire safety rules during construction installation work at the facilities of the USSR Ministry of Energy: RD 34.03.307-87. - M.: Informenergo, 1989.

16. Safety regulations for the operation of thermal mechanical equipment of power plants and heating networks: RD 34.03.201-97. - M.: NC ENAS, 1997.

17. Safety rules for operating electrical installations. - M.: Energoatomizdat, 1989.

18. Rules technical operation power stations and networks of the Russian Federation: RD 34.20.501-95*. - M.: SPO ORGRES, 1996.

* On the territory of the Russian Federation, the “Rules for the technical operation of power plants and networks of the Russian Federation” are in force, approved by Resolution of the Ministry of Fuel and Energy of Russia dated June 19, 2003 N 229.

19. Device rules and safe operation steam and hot water pipelines. Guiding document of the Gosgortekhnadzor of Russia: RD-03-94*. - M.: NPO OBT, 1994.

Change N 1*. Approved by Resolution of the Gosgortekhnadzor of Russia dated January 13, 1997 No. 1.

* On the territory of the Russian Federation, the “Rules for the construction and safe operation of steam and hot water pipelines” (PB 10-573-03) apply.

20. Rules for the operation of heat-consuming installations and consumer heating networks and Safety rules for the operation of heat-consuming installations and consumer heating networks. - M.: Energoatomizdat, 1992.

21. Standard fire safety rules for industrial enterprises: / Approved. GUPO Ministry of Internal Affairs of the USSR, 1975.

22. Standard instructions for protecting heating networks from external corrosion: RD 34.20.518-95. - M.: SPO ORGRES, 1997.

23. Standard instructions for metal control and extending the service life of the main elements of boilers, turbines and pipelines of thermal power plants: RD 10-262-98: RD 153-34.1-17.421-98*. - M.: SPO ORGRES, 1999.

* On the territory of the Russian Federation, the “Standard Instructions for Inspecting Metal and Extending the Service Life of Basic Elements of Boilers, Turbines and Pipelines of Thermal Power Plants” (RD 10-577-03) is in force.

24. Standard instructions for the technical operation of transport and distribution systems of thermal energy (heating networks): RD 153-34.0-20.507-98. - M.: SPO ORGRES, 1999.

25. Standard instructions for operation, repair and control of station network water pipelines: TI 34-70-042-85. - M.: SPO Soyuztekhenergo, 1985.

Notice of change. - M.: SPO Soyuztekhenergo, 1989.

26. Standard program for technical diagnostics of pipelines that have expired their design service life (design resource): / Approved by the State Mining and Technical Supervision Authority of Russia on 06/07/95; Approved JSC NPO CKTI.

27. Guidance document. Instructions for visual and measuring control: RD 34.10.130-96: / Approved. Ministry of Fuel and Energy of the Russian Federation; approved by Gosgortekhnadzor of Russia. - M.: 1996.

28. Steam and hot water boilers, steam and hot water pipelines. Welded joints. Quality control: RD 2730.940.103-92. - M.: NPO TsNIITMASH, 1993.

29. Guidance document. Welding, heat treatment and control of pipe systems of boilers and pipelines during installation and repair of power plant equipment (PTM-1c-293): RD 34.15.027-93*. - M.: NPO OBT, 1994.

* RD 153-34.1-003-01 is in force on the territory of the Russian Federation. -

31. Guidelines for inspection and technical certification of boiler inspection facilities. - M.: Metallurgy, 1979.

32. Guidelines for determining the readiness of heat supply systems for the heating season: MU 34-70-171-87. - M.: SPO Soyuztekhenergo, 1987.

33. Guidelines for carrying out pitting in heating networks: MU 34-70-149-86. - M.: SPO Soyuztekhenergo, 1987.

34. Information letter N 5-88. Diagnostics of the condition of pipelines of heating networks. - M.: SPO Soyuztekhenergo, 1988.

____________________________________________________________________

Brief excerpts from regulatory documentation, rules and SNiP for heating pressure testing .

Analyzing the statistics of the questions you ask and understanding that many questions regarding pressure testing of the heating system for the majority of our audience remain incomprehensible to you, we decided to make a selection from the necessary points and Rules for pressure testing, approved by the Ministry of Fuel and Energy of the Russian Federation and SNiP.

All SNiPs and rules contain more than 100 pages of information, which are sometimes difficult to understand, so in order to make the task easier for you, so that you can look at and, if necessary, refer to the desired paragraph of a specific regulatory document, we have processed the applicable regulatory documents and in brief posted on the site. Explanations to the Rules and SNiP can be found in the article: “Norms and rules for performing pressure testing of a heating system”

1. Rules for the technical operation of thermal power plants.

Developed and approved by the Ministry of Fuel and Energy of the Russian Federation. No. 115 dated March 24, 2003

clause 9.2 Heating, ventilation, air conditioning, hot water supply systems.

Hydraulic tests of equipment at heating points and heating systems should be carried out separately.
Heating points and heating systems must be tested at least once a year, with a test pressure equal to 1.25 working pressure at the heating network inlet, but not less than 0.2 MPa (2 kgf/cm2).

9.2.11 To protect against internal corrosion, heating systems must be constantly filled with deaerated, chemically purified water.

9.2.12 Tests for the strength and density of system equipment are carried out annually after the end of the heating season to identify defects, as well as before the start of the heating period after repairs are completed.

clause 9.2.13 tests for strength and density of water heating systems are carried out at test pressure, but not lower than:

— Elevator unit, water heaters for heating systems, hot water supply - 1MPa (10kgf/cm2 or 10Ati.)

- Heating systems with cast iron heating devices, stamped steel radiators - should be taken as 0.6 MPa (6 kgf/cm2 or 6Ati)

- panel and convector heating systems - 1.0 MPa (10 kgf/cm 2 or 10 Ati).

— For heaters of heating and ventilation systems - depending on the operating pressure established by the technical conditions of the manufacturer.

The minimum test pressure during hydraulic testing should be 1.25 working pressure, but not less than 0.2 MPa (2 kgf/cm2 or 2Ati).
Pipeline tests are carried out in the following order and must be carried out in compliance with the following basic requirements:

• test pressure must be provided at the top point (mark) of the pipelines; the water temperature during testing should be no higher than 45°C, air is completely removed through air venting devices at the highest points;
• the pressure is brought to the working level and maintained for the time necessary to inspect all welded and flanged connections, fittings, equipment, instruments, but not less than 10 minutes;
• If no defects are detected within 10 minutes, the pressure is brought to the test pressure.

The pressure must be maintained for 15 minutes and then reduced to working pressure. The pressure drop is recorded using a control pressure gauge.

Systems are considered to have passed the tests if, during testing:

— no “sweating” of welds or leaks from heating devices, pipelines, fittings and other equipment were detected.

— when testing the strength and density of water and steam heat supply systems, the drop within 5 minutes does not exceed 0.02 MPa (0.2 kgf/cm 2 or 0.2 Ati).

— when testing the strength and density of panel heating systems, the fall within 15 minutes does not exceed 0.01 MPa (0.1 kgf/cm 2 or 0.6 Ati).

— when testing the strength and density of hot water supply systems, the fall within 10 minutes does not exceed 0.05 MPa (0.5 kgf/cm 2 or 0.5 Ati).

— when testing the strength and density of plastic pipeline systems during a 30-minute drop, the drop does not exceed 0.06 MPa (0.6 kgf/cm 2 or 0.6 Ati).

The test results are documented in a Strength and Density Test Certificate.

If the strength and density test results do not meet the specified conditions, leaks must be identified and repaired, and then the system must be retested.

During testing, spring pressure gauges of an accuracy class of at least 1.5 with a diameter of at least 160 mm, with a division value of 0.01 MPa (0.1 kgf/cm 2 or 0.1 Ati) are used.

2. SNiP 3.05.01-85 “Internal sanitary and technical systems”

4.6. Testing of water heating and heat supply systems must be carried out with the boilers and expansion vessels turned off using the hydrostatic method with a pressure equal to 1.5 working pressure, but not less than 0.2 MPa (2 kgf/cm2 (2Ati)) at the lowest point of the system.

The system is considered to have passed the test if, within 5 minutes of being under test pressure, the pressure drop does not exceed 0.02 MPa (0.2 kgf/cm) and there are no leaks in welds, pipes, threaded connections, fittings, heating devices and equipment.

3. SNiP41-01-2003 “Heating, ventilation and air conditioning”

4.4.8 Hydraulic tests of water heating systems must be carried out at positive temperatures in the premises of the building.

Heating systems must withstand, without destruction or loss of tightness, a test water pressure exceeding the operating pressure in the system by 1.5 times, but not less than 0.6 MPa.
The test pressure value during hydraulic testing of heating systems should not exceed the maximum test pressure for heating devices, equipment, fittings and pipelines installed in the system.

rssrv.ru

Why and when is crimping performed?

Pressure testing of a heating system is hydraulic (or pneumatic) testing of its elements to determine their tightness and ability to withstand the design operating pressure of the coolant during operation, including water hammer. This is necessary in order to identify possible places of leaks, its strength, quality of installation and guarantee reliable operation of the system throughout the entire heating season.

When should it be done?

Pressure testing or hydraulic (using water), and sometimes pneumatic (using compressed air) tests of heating systems are carried out in the following cases:

• In new, newly installed ones - after completion of installation work and putting it into operation;
• In those that have already been used:
• after completion of repair or replacement of any of its elements;
• in preparation for each heating season;
• in apartment buildings also at the end of the heating season.

Who should carry out the pressure testing?

In multi-apartment residential buildings, industrial or administrative buildings, pressure testing of heating systems must be carried out by certified specialists from the services responsible for their operation and maintenance. In private houses with autonomous heating, this work can be done either by specialists or independently (most often, in cases where the heating system in the house was installed by hand). In any case, the requirements (by method, maximum pressure, time) and regulatory rules for conducting such tests, which are regulated in SNiP for this species works

How to carry out crimp testing

The procedure for crimping a heating system largely depends on the type and number of floors of the building (large multi-story building or small a private house), its complexity (number of circuits, branches, risers), wiring diagram, material and wall thickness of its elements (pipes, radiators, fittings), etc. Most often, such tests are hydraulic, that is, they are carried out by injecting water into the system , but can also be pneumatic, when excess air pressure is created in it. But hydraulic tests are carried out much more often. So let's look at this option first.

Pressure testing in a multi-apartment high-rise building

As already mentioned, in such buildings, pressure testing of the water heating system is carried out by special services, after installation and before commissioning, after repairs, before the start of each heating season and at its end, using special equipment. Based on the results of such tests, as a rule, a crimping certificate of the appropriate form is drawn up.

Pressure testing of the heating system of an apartment building

Before carrying out hydraulic tests, the following preparatory work is carried out:

• Visual inspection of the condition of the elevator (supply unit), main pipes, risers and all other elements of the heating system;
• Checking the presence and integrity of thermal insulation on heating mains.

If the system has been in operation for more than 5 years, it is advisable to flush it before pressure testing. To do this, the coolant present in it is drained and it is washed with a special solution. After which you can begin hydraulic testing.

The sequence of work during hydraulic pressure testing is as follows:

• The system is filled with water (if it has just been installed or has been washed);
• Using a special electric or manual pump, excess pressure is created in it;
• The pressure gauge monitors whether the pressure is maintained or not (within 15-30 minutes);
• If the pressure is maintained (the pressure gauge readings do not change), then the tightness is ensured, there are no leaks and all its elements can withstand the pressure of the pressure test;
• If a drop in pressure is detected, all elements (pipes, connections, radiators, additional equipment) are checked to identify water leaks;
• After the location of the leak has been determined, it is sealed or the element is replaced (pipe section, connecting fitting, shut-off valves, radiator, etc.) and the hydraulic tests are repeated.

What should the pressure test be?

The fluid pressure that is created during hydraulic tests of heating systems depends on the operating pressure in them, which, in turn, depends on the material of its pipes and radiators that were used during their installation. For new systems, the pressure testing should exceed the working pressure by 2 times, and for existing systems it should exceed it by 20-50%.

Each type of pipes and radiators is designed for a certain maximum pressure. Taking this into account, the maximum operating pressure in the system is selected and must be taken into account when choosing the pressure test. For example, in apartment buildings with cast iron radiators, the operating pressure, as a rule, does not exceed 5 atm. (bar) and is usually within 3 atm. (bar). Therefore, as a rule, pressure testing of such systems is performed with a pressure of no more than 6 atm. Systems with convector-type radiators (steel, bimetallic) can be pressurized at higher pressures (up to 10 atm).

Crimping of the input unit is performed separately, at a pressure of at least 10 atm. (1 MPa). To create such pressure, special electric pumps are used. The tests are considered successful if the pressure drop within 30 minutes is no more than 0.1 atm.

Pressure testing in a private house

In autonomous closed water heating systems of private houses, the operating pressure rarely exceeds 2.0 atm. (0.2 MPa) and, as a rule, is within 1.5 atm. Therefore, to create pressure (1.8-4 atm.) in such a system, you can use both electric and hand pumps, or connect it to the water supply system at home (usually the water pressure in it is 2-3 atm., which can be quite sufficient for hydraulic testing).

Filling the system with water must be done from below through a drain or a tap specially designed for this purpose. In this case, the air will be easily pushed out of it by the liquid coming from below upwards and removed through air valves, which should be installed at its highest point, in places where air pockets may form, as well as on each radiator.

It must also be remembered that the temperature of the water used for testing should not be higher than 45° C.

If the system is quite simple, and, moreover, it was installed with your own hands, then you can do the pressure testing yourself, performing the work in the same sequence as in an apartment building.

If, after pressure testing, the pumped water will be used in the future as a coolant, then it is necessary that it be “soft”, that is, have a hardness of no more than 75-95 units (mainly, this is the presence of magnesium and calcium salts) . An example of “soft” water can be rain or melt water, from snow or ice. If you are not sure about the hardness of the water, and an indicator of its increased hardness may be the formation of scale in an electric kettle, heating elements of a washing machine or boiler, then it is better to do an analysis in the laboratory.

In the same case, if the water used for hydraulic tests will not be used as a coolant, then after pressure testing it should be drained and the system should be immediately filled with the appropriate coolant. This is especially important if pipes made of black steel were used during wiring, and cast iron or steel were used as radiators without protecting their inner surface.

Features of air crimping

Air pressure testing is used less frequently, as a rule, for small buildings and private houses, if hydraulic tests cannot be carried out for some reason. For example, if it is necessary to check the tightness of an installed system, but there is no water or equipment for pumping it.

In this case, an electric air compressor or a mechanical (foot, hand) pump with a pressure gauge is connected to the make-up or drain valve and, with the help of it, excess air pressure is created in it. It should not exceed 1.5 atm. (bar), since at higher pressures, in case of depressurization of the connection or rupture of the pipe, injury to the people conducting the tests may occur. Instead of air valves, plugs must be installed.

Pneumatic tests require more time to hold the system under excess pressure. Since, unlike liquid, air is compressed, it takes more time to stabilize and equalize the pressure in the circuit. Initially, the pressure gauge reading may drop slowly even if it is sealed. And only after the air pressure has stabilized, it is necessary to maintain it for at least another 30 minutes.

Pressure testing of open heating systems

In order to carry out pressure testing of an open heating system, it is necessary to seal the connection point of the open expansion tank, for example, using a ball valve installed on the pipe supplying water to it. When pumping water, it can be used as an air valve, and after it is filled, the tap must be closed before creating excess pressure.

The operating pressure in such systems, as a rule, is determined by the height of the expansion tank, on the basis that for every 1 m of its excess above the level of the return inlet into the boiler, there is 0.1 atm of excess pressure in this place. In one-story houses, an open expansion tank is usually located under the ceiling or in the attic. The water column in this case will be 2-3 m high, and the excess pressure, respectively, will be 0.2-0.3 atm. (bar). When the boiler room is located in a basement or in two-story houses, the difference between the level of the expansion tank and the boiler return can be 5-8 m (0.5-0.8 bar, respectively). Consequently, in this case, to carry out hydraulic tests, a lower excess fluid pressure is required (0.3 - 1.6 bar).

Otherwise, the procedure for performing pressure testing of open systems (one-pipe and two-pipe) is the same as for closed ones.

v-teple.com

What is crimping?

In relation to pipes, this is the name for increasing pressure on an isolated section of a pipeline in order to identify leaks and potential weak points in it. In particular, sections of steel pipes seriously damaged by corrosion.

In what cases is pressure testing necessary?

• When commissioning water supply and heating systems. Steel pipes are connected by threads and welding, metal-plastic and polyethylene pipes are connected by fittings, polypropylene pipes are connected by low-temperature soldering. Any connection is a potential leak point.
  To identify all problem areas, a hydraulic pressure is created in the engineering system being tested that exceeds the maximum operating pressure for this system.
  The logic is simple: if the pipes withstood a pressure of 16 atmospheres for several hours, it means they can withstand a pressure of 8 atmospheres for a long time.

• After repair work. If the heating risers have been replaced, it is logical to test them with increased pressure.
  It is better to identify all the weak points of the new engineering system in the off-season, when stopping it will not cause a bunch of complaints from residents about cold radiators and, even worse, freezing of pipeline sections.
  The situation is not far-fetched: in the Far East and Yakutia, frosts in winter reach 40, and in some places 60 degrees below zero.
  Under such conditions, when the circulation in the heating pipe system stops, within an hour ice plugs form in the lines to the access heating devices. Thermal insulation of pipes only slightly slows down this process.

• Pressure testing of sewer pipes has the same purpose: identifying leaks. In a gravity sewer, minor leaks will only appear as a few drops hanging at the junction.
  They are easy to overlook when accepting a sewer network.
  Meanwhile, when the pipe is filled with wastewater at the peaks of water withdrawal, the drops will turn into a small stream. In addition, even a minor leak will mean a wet ceiling in apartments or office premises and the gradual destruction of ceilings and walls. Excessive pressure in the pipe will reveal all problem areas.

Please note: when crimping plastic sewers, you should especially check the fixation of the pipes with clamps.

A sewer laid in a reinforced concrete duct can operate by gravity without additional fixation, but excess pressure will tear the pipe out of the socket.

• Finally, periodic pressure testing of water supply and heating systems is used to identify emerging problems. In particular, the degree of wear of a steel pipe - after all, it is susceptible to corrosion.
  We encounter a special case of such pressure testing every spring, when heating mains are tested for density and the entire city sits without hot water for a couple of days.

A special case

When testing water wells, other goals are pursued. There you need to make sure not that there are no leaks from the pipe, but to make it impossible for water to flow into the pipe.

The reason is simple: water intake is carried out from the lower horizons, while at the upper levels there may be groundwater contaminated with domestic wastewater from cesspools and septic tanks.

How it's done?

Once it becomes clear what needs to be done, the methods become obvious.

When crimping, the following operations are performed sequentially:

1. The pipeline section is hermetically sealed off from other engineering systems. The choice of method is individual for each case.
   The valves in the elevator assembly are closed, and the heating system ring is cut off by valves. In the case of sewerage, pneumatic rubber plugs are used.

Advice: in, so to speak, field conditions for plastic sewers, you can get by with ordinary plugs for outlets, which are sealed with an O-ring.

Of course, their use implies a slight excess pressure. For a cast iron sewer, you can simply cut out a wooden chopper and wrap it with rags.

1. A pipe pressure testing pump is connected to the pipeline being tested.. This device can be manual, electric, or have its own internal combustion engine.
   The choice of a specific device depends on the required pressure and the volume of the pipeline.

Thus, to pressure test the heating system of a private house, a simple hand pump with a capacity of 3 liters per minute can be used; For pressure testing of heating mains with their volumes, the same pumps are used that provide circulation in them.

Important: hydraulic tests are carried out only with cold water. This is simply related to work safety.

Where leaks are absolutely unacceptable, air pressure testing can be carried out: however, in this case, the pressure drop in the pipe during leaks has to be monitored over a long period of time.

Air, unlike water, is compressible.

1. Water is injected into the pipeline being tested at a pressure exceeding the design operating pressure.. For systems made of heating and water supply pipes, this is usually 6-8 kgf/cm2.
   For heating mains and main water pipelines 10-12 kgf/cm2. Cast iron sewerage is checked with an excess pressure of no more than 2 atmospheres, plastic - no more than 1.6.

The presence of leaks can be easily monitored by the pressure drop: even the cheapest pipe pressure tester is equipped with a pressure gauge.

Where possible, it is better to check for leaks visually. If there are leaks, after they have been eliminated, repeated pressure testing is carried out.

Conclusion

I think we have fully answered the question of what pipe crimping is and why it is needed. The choice of a specific tool is up to you. Good luck!

o-trubah.ru

How is pressure testing of heating networks carried out?

Pressure testing of heating networks– these are special hydraulic tests that are aimed at identifying vulnerable sections of pipelines, equipment, and devices. By its nature, this procedure is mandatory, periodic, and planned. They are used to check the reliability of heat exchangers, pipelines, pumps, boilers and other heat exchange installations. These tests make it possible to identify places where defects may occur: rupture of the main pipeline, leakage, heat loss. This is achieved by creating a pressure in the system that exceeds the operating pressure.

Pressure testing of heating networks detects leaks in fittings and pipelines, expansion joints and flange connections, and also allows you to detect leaks and “fogging” at welds. The main objectives of the test are to determine the endurance, tightness and reliability of pipes. These checks allow your heating system to be ready for the upcoming heating season. It is worth noting that testing networks requires good preparation, because all identified defects need to be corrected in a timely manner. Modern equipment allows us to reduce the costs of carrying out the necessary work.

Before starting the test, all heat exchangers, radiators and pipelines must be flushed. At the beginning of crimping, the sectional area is filled with water. During the filling process, in the return pipeline section, all drain valves and taps are closed, only the air vents remain open. When water appears in them without air, the taps are turned off. After filling the section with water, a 2-3 hour wait is applied. After this, they begin to slowly heat the water. The heating rate should not exceed 30°C per hour. Minor faults are eliminated during the heating process. To eliminate major faults, you need to stop the network. Pressure testing of heating networks allows you to identify all the weak points in the system. After testing the system for strength, the pipeline must be flushed to remove scale and dirt.

Pressure testing of heating networks considered a necessary and indispensable operation. It confirms the readiness and reliability of equipment and pipelines for operation. Pressure testing helps prevent accidents that can pose a danger to the health and even lives of people.

remenergo.net

Regulations

The operating pressure and the design pressure for the procedures depend on the height of the water, that is, on the number of floors. The analysis is carried out by a specialist at the test site. The difference between pressure testing of heating systems for cottages and private houses is that it requires a small pressure of about 2 atmospheres, this allows the use of only water supply. In this case, the liquid should fill the entire structure without air bubbles. In multi-storey buildings, the working pressure is about 6–8 atmospheres, so pump hydraulic pressure testing is necessarily used there.

For the crimping process, there are documents that define the stages, the sequence of work, in compliance with safety regulations, the required equipment, and methods for activating the result:

1. “Rules for the technical operation of thermal power plants No. 115 dated March 24, 2003,” which were developed and approved by the Ministry of Fuel and Energy of the Russian Federation.
2. “Heating, ventilation and air conditioning” SNiP 41–01–2003.
3. “Internal sanitary systems” SNiP 3.05.01–85.

Based on all the standards, the following actions can be distinguished when performing crimp testing:

• The gradual creation of pressure in the system exceeding the working one.
• Hold the test object for about half an hour with constant pressure control.
• Activating the result.
• Elimination, if necessary, of defects.

All pipeline elements that are in disrepair will become unusable after testing, while those that are in good condition will continue to operate.

Performing hydraulic pressure testing

If it is necessary to check a working structure, then pressure testing of the heating is done only after the system has been completely turned off and the coolant has been drained. It is recommended that every 5–7 years additional chemical or hydropneumatic flushing be carried out inside the circuit to remove deposits that interfere with normal functioning. This procedure is required after initial installation.

Next, the entire system is inspected and defective components are replaced. Through the ball drain valve, a gradual filling of water begins from the bottom up to avoid the formation of air bubbles from the water supply with or without a pump. All air valves must be opened. A pressure gauge must be included in the test circuit, the readings of which are monitored. If it shows a drop in pressure, then the system is not sealed and requires repair. Otherwise, it is concluded that the tests were successful. If the test result is negative, water leaks are located and emergency elements are replaced. After this, the entire set of activities is repeated again.

All test results are validated by the personnel conducting them and certified by double-sided signatures from the customer and the contractor. The report notes the time of work, the pressure used with the calculation and the period of its exposure, and the results. To perform crimping in children's rooms, medical institutions and in apartment buildings the participation of supervisory authorities is mandatory.

Pressure testing of air conditioning systems

There is also a need to check the tightness of air conditioning systems. They also use pressure testing similar to hydraulic. This procedure must be carried out after any repair, for example, after replacing a radiator. To check the tightness of the soldering, a mixture of dry nitrogen with R22 refrigerant or only dry nitrogen is driven into the system. The test pressure is reached, after which, using a special leak detector in the first case and simply soap foam in the second, the absence or presence of defects is recorded. The system is being repaired or brought back into working condition.

Cost of crimping

The obligation to carry out regular pressure testing rests with the owners of the houses or the services that serve them, for example, utilities. That is, homeowners will have to resort to the help of specialists who will perform the entire range of necessary procedures.

There are many companies in each region that conduct such tests. Those wishing to use their services are interested in the professionalism of their employees and compliance with sanitary and construction standards. An important parameter when choosing an organization is the price of heating pressure testing. In all specific cases, it is calculated individually, when, after consultation with an on-site specialist, a complete list of required measures and an estimate are drawn up. The final cost will depend on the condition of the pipelines, the list of work performed and the tariffs of the performing company.

With proper and timely pressure testing of air conditioning and heating systems, as well as all other elements, their trouble-free and trouble-free service during operation is guaranteed. Necessary requirement is compliance with regulatory standards and the participation of qualified personnel in all work.

masterim.guru

Why hydrotest?

As you know, the heating system is a closed circuit operating under excess pressure. Any leaks in the threaded connections of the fittings or at the connection points of radiators will lead to water leakage, flooding of premises, damage to building structures, finishing, etc. And since the system operates in winter time under pressure and high temperatures coolant, then during accidents situations may also arise that threaten the life and health of people. The consequences of leaking heating systems can be very expensive and problematic in terms of eliminating them, especially in winter.

Therefore, hydraulic tests of heating and heat supply systems are mandatory measures both at the time of commissioning of the facility and at the stage of preparatory work before the heating season.

In some cases, the absence of a test certificate for a building’s heat supply systems is a guaranteed failure heat supply organization to release heat into the building before the start of the heating period. Therefore, the organization operating the building must be aware of the procedure for preparing networks and must have the appropriate qualifications to test heating systems. In addition, pressure testing of heating systems connected to the heating networks of a city or town is part of the heat supply contract.

The main preparatory work and testing of heating systems include the following activities:

• system pressure testing,
• flushing of pipelines.

What is system testing?

Pressure testing of heating systems means a hydrodynamic test of the pipeline network, that is, the system is maintained under a certain excess pressure for a certain period of time.

All heating system equipment is also subject to strength testing: heat exchangers, radiators, shut-off and control valves, pumping stations and other network elements.

In addition to hydraulic tests of heating systems, all other heat supply systems are subject to annual inspection: heat input units into the building, individual heating points, heating units, heat supply systems for supply ventilation and air-thermal curtains, heating systems and underfloor heating, boiler rooms, etc.

Standards governing testing procedures

Both in design, installation and testing work without knowledge regulatory framework It will be impossible to competently perform pressure testing of heating systems.

For example, SNiP 41-01-2003 provides basic recommendations for testing heating systems:

• the air temperature in the building must be above zero degrees;
• pressure testing should not be greater than the maximum maximum pressure of equipment and materials in the heating system;
• the pressure test pressure must be 50% greater than the operating pressure of the heating system and equipment, but the indicator should not be lower than 0.6 MPa.

SNiP 3.05.01-85 regulates:

• carry out hydraulic tests of large-scale components at the assembly site;
• if the pressure in the system drops during hydraulic tests, it is necessary to visually detect the location of the leak, eliminate the leak, and then continue testing for leaks;
• Pressure testing of pipelines with installed valves or wedge valves should be performed by turning the control knob twice;
• sectional heating devices that are not factory assembled must also be pressed on site;
• hidden wiring pipelines must be tested under high pressure before finishing work;
• insulated pipes are subject to pressure testing before applying thermal insulation;
• During testing of heat supply systems, hot water boilers and membrane tanks must be turned off;
• the system is considered operational and has passed the testing measures if the pressure test has not decreased within 30 minutes and no water leaks have been detected by the visual method;
• Testing a heating system for correct and uniform heating is called a thermal test. Such activities must be carried out for seven hours with water at a temperature of at least 60 degrees. If in summer time the heat source does not produce the pressure test temperature, then the tests are postponed until the temporary heat supply is resumed, or until connected to the heat source.

All hydraulic tests are recorded in the pressure test report, and tests of hidden pipelines are accompanied by a sheet for hidden work.

The procedure and technological features of performing pressure testing of the heating system

Hydraulic tests of heat supply systems are usually carried out with different pressure tests depending on the purpose of the system and the type of equipment used. For example, a heat input unit into a building is pressurized with a pressure of 16 atmospheres, heat supply systems for ventilation and ITP, as well as heating systems for multi-storey buildings - with a pressure of 10 atmospheres, and heating systems for individual houses - with a pressure from 2 to 6 atm.

Heating systems of newly constructed buildings are pressed with 1.5-2 times greater pressure from the worker, and heating systems of old and dilapidated houses are pressed with lower values ​​in the range of 1.15-1.5. In addition, when crimping systems with cast iron radiators, the pressure range should not exceed 6 atm, but with installed convectors - about 10.

Thus, when choosing pressure testing, you should carefully read the equipment data sheets. It should not be higher than the maximum pressure of the “weakest” link in the system.

First, the heating or heat supply system is filled with water. If the heating system is filled with a low-freezing coolant, then pressure testing is carried out first with water, then with a solution with additives. You should know that due to lower surface tension, coolants based on ethylene glycol or propylene glycol are more fluid than water, so in case of minor leaks on the threaded connections, sometimes they should only be tightened slightly.

When preparing a functioning heating system for the heating season, the working coolant must be drained and refilled with clean water for pressure testing. The heating system is usually filled at the lowest point of the boiler room or heating unit through a drain ball valve. In parallel with filling the heating system, air must be bleed through air vents on risers, the top points of branches or through Mayevsky taps on radiators. To prevent airing of the heating system, the system is filled only from the bottom up.

Then the system pressure is increased to the calculated one, with the pressure drop monitored by measuring pressure gauges. In parallel with pressure monitoring, a visual inspection of the entire system, pipeline assemblies, threaded connections and equipment is carried out for the formation of leaks and the appearance of drops on the seams. If condensation forms on the system after filling with water, the pipelines must be dried and then inspected further.

Heating devices and pipeline sections hidden in building structures are subject to mandatory inspection.

The heating system is kept under pressure for at least 30 minutes, and if no leaks are detected and no pressure drop is recorded, then it is considered that the system has passed pressure testing.

In some cases, the pressure drop is permissible, but within limits not exceeding 0.1 atmospheres, and provided that a visual inspection does not confirm the formation of water leaks and violations of the tightness of welded and threaded connections.

If the result of hydraulic tests is negative, carry out renovation work with further repeated crimping.

Upon completion of the testing work, a test certificate is drawn up in the form specified in the main regulatory documents.

Pneumatic testing of heating systems

The main limitation of hydraulic tests is carrying out work in rooms with a positive temperature, which is extremely difficult in a building under construction. Therefore, often before the main test work carry out pressure testing of the heating system with air.

The compressor is connected to the drain valve or to the Mayevsky valve at any point in the system, increased air pressure is injected, and the system is maintained certain time without pressure drop.

Flushing heating systems

Hydropneumatic flushing of heating systems is a mandatory measure when preparing the heating system for start-up before the start of the heating season.

Water circulates through a closed circuit of the heating system during the heating period, and when heated and cooled, hardness salts are deposited. And this, together with the processes of corrosion of the internal walls of the pipes, leads to the deposition of scale on them. Scale significantly reduces the internal cross-section of pipelines, increases the hydraulic resistance of the system and reduces the heat transfer of radiators.

In high-temperature heating systems, scale leads to local overheating and further formation of fistulas. Scale deposits one millimeter thick lead to a reduction in heat transfer from the heating system by 15-20%. And in on a global scale- this is a colossal loss of thermal power and a significant decrease in the energy efficiency of the system with a significant increase in the cost of heating the building.

Flushing heating systems is the same necessary annual event as pressure testing, and is carried out before the start of the heating season or at the time of commissioning.

The main sign of a “clogged” heating system is an increase in coolant consumption, an increase in warm-up time, or uneven heating of the radiators. In these cases, situations often arise when the pipelines are hot, but the radiators are not yet warmed up.

The hydropneumatic method involves filling the system with clean water and connecting an air compressor to it. Excessive air pressure increases the flow rate of the coolant and creates turbulent fluid flows. These flows in places of scale deposits create vortex vibrations, as a result of which contaminant particles are torn off the surface of the walls.

When supplying high pressure air, the valve on the air bleed valves must be closed, and a check valve must be installed to protect the compressor from water entering the system.

Also, for flushing the system, there are special solutions that break down the scale deposited on the walls of pipelines and thereby reduce their hydraulic resistance.

Hydraulic testing services

If the heating system is installed contractor at the stage of construction of new housing, then the responsibility for pressure testing of pipelines lies entirely with the contractor.

In the case when the heating system is already functioning, regardless of whether it is a residential building, a municipal institution, a shopping or office complex, pressure testing is carried out by an organization that services all systems of the building. In housing construction, the law provides for responsibilities management company keep heating systems in working order, and, therefore, take measures to prepare for the heating season.

For administrative and other complexes, testing of systems is carried out either by the operating organization or by a contractor who has all the necessary permits to carry out a complex of work.

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SNiP 3.05.03-85
________________
Registered by Rosstandart as SP 74.13330.2011. -
Database manufacturer's note.

BUILDING REGULATIONS

HEATING NETWORK

Date of introduction 1986-07-01

DEVELOPED by the Orgenergostroy Institute of the USSR Ministry of Energy (L. Ya. Mukomel - topic leader; Candidate of Technical Sciences S. S. Yakobson).

INTRODUCED by the USSR Ministry of Energy.

PREPARED FOR APPROVAL BY Glavtekhnormirovanie Gosstroy USSR (N. A. Shishov).

APPROVED by Decree of the USSR State Committee for Construction Affairs dated October 31, 1985 N 178.

With the entry into force of SNiP 3.05.03-85 “Heating networks”, SNiP III-30-74 “Water supply, sewerage and heat supply. External networks and structures” loses its force.

AGREED with the State Mining and Technical Supervision Committee of the USSR on April 15, 1985.

These rules apply to the construction of new, expansion and reconstruction of existing heating networks,

transporting hot water at temperature t and steam at temperature t		200 degrees C and pressure 440 degrees C and pressure			2.5 MPa (25 kgf/sq.cm) 6.4 MPa (64 kgf/sq.cm)

from the source of thermal energy to heat consumers (buildings, structures).

1. GENERAL PROVISIONS

1. GENERAL PROVISIONS

1.1. When constructing new, expanding and reconstructing existing heating networks, in addition to the requirements of working drawings, work plans (WPP) and these rules, the requirements of SNiP 3.01.01-85, SNiP 3.01.03-84, SNiP III-4-80 and standards must also be observed .

1.2. Work on the manufacture and installation of pipelines, which are subject to the requirements of the Rules for the Construction and Safe Operation of Steam and Hot Water Pipelines of the USSR Gosgortekhnadzor (hereinafter referred to as the Rules of the USSR Gosgortekhnadzor), must be carried out in accordance with the specified Rules and the requirements of these rules and regulations.

1.3. Completed heating networks should be put into operation in accordance with the requirements of SNiP III-3-81.

2. EARTHWORK

2.1. Excavation and foundation work must be carried out in accordance with the requirements of SNiP III-8-76, SNiP 3.02.01-83, SN 536-81 and this section.

2.2. The smallest width of the trench bottom for channelless pipe laying should be equal to the distance between the outer side edges of the insulation of the outermost pipelines of heating networks (associated drainage) with an addition on each side for pipelines of a nominal diameter

The width of the pits in the trench for welding and insulation of pipe joints during channelless laying of pipelines should be taken equal to the distance between the outer side edges of the insulation of the outermost pipelines with the addition of 0.6 m on each side, the length of the pits - 1.0 m and the depth from the bottom edge of the pipeline insulation - 0.7 m, unless other requirements are justified by working drawings.

2.3. The smallest width of the bottom of the trench during channel laying of heating networks should be equal to the width of the channel, taking into account formwork (in monolithic sections), waterproofing, associated drainage and drainage devices, trench fastening structure with the addition of 0.2 m. In this case, the width of the trench should be at least 1 .0 m.

If it is necessary for people to work between the outer edges of the canal structure and the walls or slopes of the trench, the width between the outer edges of the canal structure and the walls or slopes of the trench in the clear must be at least: 0.70 m - for trenches with vertical walls and 0.30 m - for trenches with slopes.

2.4. Backfilling of trenches during channelless and channel laying of pipelines should be carried out after preliminary testing of pipelines for strength and tightness, complete completion of insulation and construction and installation work.

Backfilling must be done in the specified technological sequence:

tamping of sinuses between pipelines of channelless laying and the base;

simultaneous uniform filling of the sinuses between the walls of the trench and pipelines during channelless installation, as well as between the walls of the trench and channel, chamber during channel installation to a height of at least 0.20 m above the pipelines, channels, chambers;

backfilling the trench to the design marks.

Backfilling of trenches (pits) to which additional external loads are not transferred (except for the own weight of the soil), as well as trenches (pits) at intersections with existing underground communications, streets, roads, driveways, squares and other structures settlements and industrial sites should be carried out in accordance with the requirements of SNiP III-8-76.

2.5. After turning off the temporary dewatering devices, the channels and chambers must be visually inspected for the absence of groundwater in them.

3. CONSTRUCTIONS AND INSTALLATION OF BUILDING STRUCTURES

3.1. Work on the construction and installation of building structures should be carried out in accordance with the requirements of this section and the requirements of:

SNiP III-15-76 - for the construction of monolithic concrete and reinforced concrete structures of foundations, supports for pipelines, chambers and other structures, as well as for grouting joints;

SNiP III-16-80 - for installation of prefabricated concrete and reinforced concrete structures;

SNiP III-18-75 - when installing metal structures of supports, spans for pipelines and other structures;

SNiP III-20-74 - for waterproofing channels (chambers) and other building structures (structures);

SNiP III-23-76 - for the protection of building structures from corrosion.

3.2. The outer surfaces of channel and chamber elements supplied to the route must be covered with a coating coating or adhesive waterproofing in accordance with the working drawings.

The installation of channel elements (chambers) in the design position should be carried out in a technological sequence linked to the project for the installation and preliminary testing of pipelines for strength and tightness.

Support pads for sliding supports of pipelines must be installed at the distances specified in SNiP II-G. 10-73* (II-36-73*).

3.3. Monolithic fixed panel supports must be made after installation of pipelines in the panel support area.

3.4. In places where channelless pipelines are inserted into channels, chambers and buildings (structures), the cases of bushings must be put on the pipes during their installation.

At the entrances of underground pipelines into buildings, devices must be installed (in accordance with the working drawings) to prevent gas from penetrating into the buildings.

3.5. Before installing the upper trays (plates), the channels must be cleared of soil, debris and snow.

3.6. Deviation of the slopes of the bottom of the heating network channel and drainage pipelines from the design is allowed by +/- 0.0005, while the actual slope must be no less than the minimum allowable according to SNiP II-G.10-73* (II-36-73*).

Deviation of installation parameters of other building structures from the design ones must comply with the requirements of SNiP III-15-76, SNiP III-16-80 and SNiP III-18-75.

3.7. The construction organization project and the work execution project must provide for the advanced construction of drainage pumping stations and water release devices in accordance with the working drawings.

3.8. Before laying in a trench, drainage pipes must be inspected and cleared of soil and debris.

3.9. Layer-by-layer filtering of drainage pipelines (except for pipe filters) with gravel and sand must be performed using inventory separation forms.

3.10. The straightness of sections of drainage pipelines between adjacent wells should be checked by inspection “to the light” using a mirror before and after backfilling the trench. The pipe circumference reflected in the mirror must have the correct shape. The permissible horizontal deviation from the circle should be no more than 0.25 of the pipe diameter, but no more than 50 mm in each direction.

Deviation from correct form Vertical circles are not allowed.

4. INSTALLATION OF PIPELINES

4.1. The installation of pipelines must be carried out by specialized installation organizations, and the installation technology must ensure high operational reliability of the pipelines.

4.2. Parts and pipeline elements (expansion joints, mud traps, insulated pipes, as well as pipeline assemblies and other products) must be manufactured centrally (in factories, workshops, workshops) in accordance with standards, technical specifications and design documentation.

4.3. Laying of pipelines in a trench, channel or on above-ground structures should be carried out using the technology provided for by the work project and excluding the occurrence of residual deformations in the pipelines, violation of the integrity of the anti-corrosion coating and thermal insulation by using appropriate installation devices, correct placement of simultaneously working lifting machines and mechanisms.

The design of fastening mounting devices to pipes must ensure the safety of the coating and insulation of pipelines.

4.4. The laying of pipelines within the panel support must be carried out using pipes of the maximum delivery length. In this case, the welded transverse seams of pipelines should, as a rule, be located symmetrically relative to the panel support.

4.5. Laying of pipes with a diameter of over 100 mm with a longitudinal or spiral seam should be carried out with an offset of these seams by at least 100 mm. When laying pipes with a diameter of less than 100 mm, the displacement of the seams must be at least three times the thickness of the pipe wall.

Longitudinal seams must be within the upper half of the circumference of the pipes being laid.

Steeply curved and stamped pipeline bends are allowed to be welded together without a straight section.

Welding of pipes and bends into welded joints and bent elements is not allowed.

4.6. When installing pipelines, the movable supports and hangers must be shifted relative to the design position by the distance specified in the working drawings, in the direction opposite to the movement of the pipeline in working condition.

In the absence of data in the working drawings, the movable supports and hangers of horizontal pipelines must be shifted taking into account the correction for the outside air temperature during installation by the following values:

sliding supports and elements for fastening hangers to the pipe - by half the thermal elongation of the pipeline at the attachment point;

roller bearing rollers - by a quarter of thermal elongation.

4.7. When installing pipelines, spring hangers must be tightened in accordance with the working drawings.

When performing hydraulic tests of steam pipelines with a diameter of 400 mm or more, an unloading device should be installed in spring suspensions.

4.8. Pipe fittings must be installed in a closed state. Flange and welded connections of fittings must be made without tension in the pipelines.

The deviation from the perpendicularity of the plane of the flange welded to the pipe relative to the pipe axis should not exceed 1% of the outer diameter of the flange, but be no more than 2 mm at the top of the flange.

4.9. Bellows (wavy) and stuffing box expansion joints should be installed assembled.

When laying heating networks underground, installation of compensators in the design position is allowed only after preliminary testing of pipelines for strength and tightness, backfilling of channelless pipelines, channels, chambers and panel supports.

4.10. Axial bellows and stuffing box expansion joints should be installed on pipelines without breaking the axes of the expansion joints and the axes of the pipelines.

Permissible deviations from the design position of the connecting pipes of expansion joints during their installation and welding must be no more than those specified in technical conditions for the manufacture and supply of compensators.

4.11. When installing bellows expansion joints, they are not allowed to twist relative to the longitudinal axis and sag under the influence of their own weight and the weight of adjacent pipelines. Slinging of expansion joints should be done only by the pipes.

4.12. The installation length of bellows and stuffing box expansion joints must be taken according to the working drawings, taking into account corrections for the outside air temperature during installation.

Stretching of expansion joints to the installation length should be done using devices provided for in the design of expansion joints, or tensioning mounting devices.

4.13. Stretching of the U-shaped compensator should be carried out after completion of pipeline installation, quality control of welded joints (except for closing joints used for tension) and fastening of fixed support structures.

The compensator should be stretched by the amount indicated in the working drawings, taking into account the correction for the outside air temperature when welding the closing joints.

Stretching of the compensator must be carried out simultaneously on both sides at joints located at a distance of no less than 20 and no more than 40 pipeline diameters from the axis of symmetry of the compensator, using tension devices, unless other requirements are justified by the design.

On the section of the pipeline between the joints used for stretching the compensator, there should be no preliminary displacement of supports and hangers in comparison with the design (detailed design).

4.14. Immediately before assembling and welding pipes, it is necessary to visually inspect each section to ensure that there are no foreign objects or debris in the pipeline.

4.15. Deviation of the pipeline slope from the design is allowed by +/- 0.0005. In this case, the actual slope must be no less than the minimum allowable according to SNiP II-G.10-73* (II-36-73*).

Movable pipeline supports must be adjacent to the supporting surfaces of structures without gaps or distortion.

4.16. When performing installation work, the following types of hidden work are subject to acceptance with drawing up inspection reports in the form given in SNiP 3.01.01-85: preparation of the surface of pipes and welded joints for anti-corrosion coating; performing anti-corrosion coating of pipes and welded joints.

A report on the stretching of compensators should be drawn up in the form given in the mandatory Appendix 1.

4.17. Protection of heating networks from electrochemical corrosion must be carried out in accordance with the Instructions for the protection of heating networks from electrochemical corrosion, approved by the USSR Ministry of Energy and the Ministry of Housing and Utilities of the RSFSR and agreed with the USSR State Construction Committee.

5. ASSEMBLY, WELDING AND QUALITY CONTROL OF WELDED JOINTS

5.1. Welders are allowed to tack and weld pipelines if they have documents authorizing them to carry out welding work in accordance with the Rules for Certification of Welders approved by the USSR State Mining and Technical Supervision.

5.2. Before being allowed to work on welding pipeline joints, the welder must weld the permitted joint in production conditions in the following cases:

with a break in work for more than 6 months;

when welding pipelines with changes in the steel group, welding materials, technology or welding equipment.

On pipes with a diameter of 529 mm or more, it is allowed to weld half the perimeter of the permissible joint; Moreover, if the permissible joint is vertical and non-rotating, the ceiling and vertical sections of the seam must be welded.

The permissible joint must be of the same type as the production joint (the definition of a joint of the same type is given in the Rules for Certification of Welders of the USSR State Mining and Technical Supervision).

The permissible joint is subject to the same types of control that production welded joints are subjected to in accordance with the requirements of this section.

Manufacturing jobs

5.3. The welder is obliged to knock out or fuse the mark at a distance of 30-50 mm from the joint on the side accessible for inspection.

5.4. Before assembly and welding, it is necessary to remove the end caps, clean the edges and the adjacent inner and outer surfaces of the pipes to a width of at least 10 mm to bare metal.

5.5. Welding methods, as well as types, structural elements and dimensions of welded joints of steel pipelines must comply with GOST 16037-80.

5.6. Pipeline joints with a diameter of 920 mm or more, welded without a remaining backing ring, must be made with welding of the root of the seam inside the pipe. When welding inside a pipeline, the responsible person must be issued a work permit for high-risk work. The issuance procedure and form of the permit must comply with the requirements of SNiP III-4-80.

5.7. When assembling and welding pipe joints without a backing ring, the displacement of the edges inside the pipe should not exceed:

for pipelines that are subject to the requirements of the USSR State Mining and Technical Supervision Rules - in accordance with these requirements;

for other pipelines - 20% of the pipe wall thickness, but not more than 3 mm.

In pipe joints assembled and welded on the remaining backing ring, the gap between the ring and inner surface pipes should not exceed 1 mm.

5.8. The assembly of pipe joints for welding should be done using mounting centering devices.

Correction of smooth dents at the ends of pipes for pipelines that are not subject to the requirements of the USSR Gosgortekhnadzor Rules is allowed if their depth does not exceed 3.5% of the pipe diameter. Sections of pipes with deeper dents or tears should be cut out. The ends of pipes with nicks or chamfers with a depth of 5 to 10 mm should be cut off or corrected by surfacing.

5.9. When assembling a joint using tacks, their number should be for pipes with a diameter up to 100 mm - 1 - 2, with a diameter over 100 to 426 mm - 3 - 4. For pipes with a diameter over 426 mm, tacks should be placed every 300-400 mm around the circumference.

The tacks should be evenly spaced around the perimeter of the joint. The length of one tack for pipes with a diameter of up to 100 mm is 10 - 20 mm, with a diameter over 100 to 426 mm - 20 - 40, with a diameter over 426 mm - 30 - 40 mm. The tack height should be for a wall thickness S up to 10 mm - (0.6 - 0.7) S, but not less than 3 mm, for a larger wall thickness - 5 - 8 mm.

The electrodes or welding wire used for tack welding must be of the same grade as that used for welding the main seam.

5.10. Welding of pipelines that are not subject to the requirements of the USSR State Mining and Technical Supervision Rules may be carried out without heating the welded joints:

at outside air temperatures down to minus 20 degrees C - when using pipes made of carbon steel with a carbon content of no more than 0.24% (regardless of the pipe wall thickness), as well as pipes made of low-alloy steel with a wall thickness of no more than 10 mm;

at outside air temperatures down to minus 10 degrees C - when using pipes made of carbon steel with a carbon content of over 0.24%, as well as pipes made of low-alloy steel with a wall thickness of over 10 mm.

At lower outside temperatures, welding should be carried out in special booths, in which the air temperature in the area of ​​​​the welded joints should be maintained not lower than the specified one.

It is allowed to carry out welding work in the open air by heating the welded ends of pipes at a length of at least 200 mm from the joint to a temperature of at least 200 degrees C. After welding is completed, a gradual decrease in the temperature of the joint and the adjacent pipe area must be ensured by covering them with asbestos sheets or using another method.

Welding (at negative temperatures) of pipelines that are subject to the requirements of the USSR Gosgortekhnadzor Rules must be carried out in compliance with the requirements of these Rules.

In rain, wind and snow, welding work can only be carried out if the welder and the welding site are protected.

5.11. Welding of galvanized pipes should be carried out in accordance with SNiP 3.05.01-85.

5.12. Before welding pipelines, each batch of welding materials (electrodes, welding wire, fluxes, shielding gases) and pipes must be subjected to incoming inspection:

for the presence of a certificate with verification of the completeness of the data contained in it and their compliance with the requirements of state standards or technical specifications;

to ensure that each box or other package contains a corresponding label or tag with verification of the data on it;

for the absence of damage (damage) to the packaging or the materials themselves. If damage is detected, the question of the possibility of using these welding materials must be resolved by the organization performing the welding;

on technological properties electrodes in accordance with GOST 9466-75 or departmental regulatory documents, approved in accordance with SNiP 1.01.02-83.

5.13. When applying the main seam, it is necessary to completely overlap and weld the tacks.

Quality control

5.14. Quality control of welding work and welded joints of pipelines should be carried out by:

checking the serviceability of welding equipment and measuring instruments, the quality of the materials used;

operational control during the assembly and welding of pipelines;

external inspection of welded joints and measurements of seam sizes;

checking the continuity of joints using non-destructive testing methods - radiographic (X-ray or gamma rays) or ultrasonic flaw detection in accordance with the requirements of the USSR State Mining and Technical Supervision Rules, GOST 7512-82, GOST 14782-76 and other standards approved in the prescribed manner. For pipelines that are not subject to the USSR State Mining and Technical Supervision Rules, it is allowed to use magnetographic testing instead of radiographic or ultrasonic testing;

mechanical tests and metallographic studies of control welded joints of pipelines, which are subject to the requirements of the USSR State Mining and Technical Supervision Rules, in accordance with these Rules;

tests for strength and tightness.

5.15. During operational quality control of welded joints of steel pipelines, it is necessary to check compliance with the standards of structural elements and dimensions of welded joints (blunting and cleaning of edges, the size of gaps between edges, width and reinforcement of the weld), as well as the technology and welding mode, the quality of welding materials, tacks and weld seam

5.16. All welded joints are subject to external inspection and measurement.

Pipeline joints welded without a backing ring with weld root welding are subject to external inspection and measurement of the dimensions of the seam outside and inside the pipe, in other cases - only from the outside. Before inspection, the weld seam and the adjacent surfaces of the pipes must be cleaned of slag, splashes of molten metal, scale and other contaminants to a width of at least 20 mm (on both sides of the seam).

The results of external inspection and measurement of dimensions of welded joints are considered satisfactory if:

there are no cracks of any size and direction in the seam and the adjacent area, as well as undercuts, sagging, burns, unsealed craters and fistulas;

the dimensions and number of volumetric inclusions and depressions between the rollers do not exceed the values ​​​​given in table. 1;

the dimensions of lack of penetration, concavity and excess penetration at the root of the weld of butt joints made without a remaining backing ring (if it is possible to inspect the joint from inside the pipe) do not exceed the values ​​​​given in table. 2.

Joints that do not meet the listed requirements must be corrected or removed.

Table 1

	Maximum allowed linear size of the defect, mm	Maximum acceptable number of defects for any 100 mm of seam length
Volumetric inclusion of a round or elongated shape with a nominal wall thickness of welded pipes in butt joints or a smaller weld leg in corner joints, mm:
St. 5.0 to 7.5
Recession (deepening) between the rollers and scaly structure of the weld surface with the nominal wall thickness of the pipes being welded in butt joints or with a smaller weld leg in corner joints, mm:
		Not limited

table 2

Pipelines, for which Rules of Gosgortekhnadzor of the USSR		Maximum permissible height (depth), % of nominal wall thickness	Maximum permissible total length along the perimeter of the joint
Spread	Concavity and lack of penetration at the root of the seam Exceeding penetration	10, but not more than 2 mm 20, but not more than 2 mm	20% perimeter
Do not apply	Concavity, excess penetration and lack of penetration at the root of the weld		1/3 perimeter

5.17. Welded joints are subjected to continuity testing using non-destructive testing methods:

pipelines that are subject to the requirements of the USSR State Mining and Technical Supervision Rules, with an outer diameter of up to 465 mm - in the volume provided for by these Rules, with a diameter over 465 to 900 mm in a volume of at least 10% (but not less than four joints), with a diameter over 900 mm - in the volume at least 15% (but not less than four joints) of the total number of joints of the same type made by each welder;

pipelines that are not subject to the requirements of the USSR State Mining and Technical Supervision Rules, with an outer diameter of up to 465 mm in a volume of at least 3% (but not less than two joints), with a diameter over 465 mm - in a volume of 6% (but not less than three joints) of the total number of similar joints performed by each welder; in case of checking the continuity of welded joints using magnetic testing, 10% of the total number of joints subjected to control must also be checked using the radiographic method.

5.18. Non-destructive testing methods should be applied to 100% of welded joints of heating network pipelines laid in non-passable channels under roadways, in cases, tunnels or technical corridors together with other utilities, as well as at intersections:

railways and tram tracks- at a distance of at least 4 m, electrified railways - at least 11 m from the axis of the extreme track;

railways of the general network - at a distance of at least 3 m from the nearest roadbed structure;

highways - at a distance of at least 2 m from the edge of the roadway, reinforced shoulder strip or the bottom of the embankment;

metro - at a distance of at least 8 m from structures;

power, control and communication cables - at a distance of at least 2 m;

gas pipelines - at a distance of at least 4 m;

main gas and oil pipelines - at a distance of at least 9 m;

buildings and structures - at a distance of at least 5 m from walls and foundations.

5.19. Welds should be rejected if, when tested by non-destructive testing methods, cracks, unwelded craters, burns, fistulas, as well as lack of penetration at the root of the weld made on the backing ring are detected.

5.20. When checking by radiographic method the welded seams of pipelines, which are subject to the requirements of the USSR Gosgortekhnadzor Rules, pores and inclusions are considered acceptable defects, the dimensions of which do not exceed the values ​​​​specified in Table. 3.

Table 3

Nominal wall thickness	Maximum permissible sizes of pores and inclusions, mm						Total pore length and
	individual		clusters				inclusions
	width (diameter)		width (diameter)		width (diameter)		for any 100 mm seam, mm
St. 2.0 to 3.0

The height (depth) of lack of penetration, concavity and excess penetration at the root of the weld of a joint made by one-sided welding without a backing ring should not exceed the values ​​​​specified in table. 2.

Acceptable defects in welds according to the results of ultrasonic testing are considered to be defects, measured characteristics, the number of which does not exceed those indicated in the table. 4.

Table 4

Nominal wall thickness	Artificial size	Valid conditional	Number of defects for any 100 mm seam
pipes, mm	corner reflector (“notches”), mm x mm	length of an individual defect, mm	large and small in total	large
From 4.0 to 8.0
St. 8.0 " 14.5
Notes: 1. A defect is considered large if its nominal length exceeds 5.0 mm for a wall thickness of up to 5.5 mm and 10 mm for a wall thickness of over 5.5 mm. If the conditional length of the defect does not exceed the specified values, it is considered minor. 2. When electric arc welding without a backing ring with one-sided access to the seam, the total conditional length of defects located at the root of the seam is allowed up to 1/3 of the pipe perimeter. 3. The amplitude level of the echo signal from the defect being measured should not exceed the amplitude level of the echo signal from the corresponding artificial corner reflector (“notch”) or equivalent segmental reflector.

5.21. For pipelines that are not subject to the requirements of the USSR Gosgortekhnadzor Rules, acceptable defects in the radiographic inspection method are pores and inclusions, the dimensions of which do not exceed the maximum permissible according to GOST 23055-78 for class 7 welded joints, as well as lack of penetration, concavity and excess penetration at the root of a seam made by one-sided electric arc welding without a backing ring, the height (depth) of which should not exceed the values ​​​​specified in table. 2.

5.22. When non-destructive testing methods are used to identify unacceptable defects in pipeline welds that are subject to the requirements of the USSR Gosgortekhnadzor Rules, repeated quality control of the seams established by these Rules must be carried out, and in pipeline welds that are not subject to the requirements of the Rules - in double the number of joints according to compared to that specified in clause 5.17.

If unacceptable defects are detected during re-inspection, all joints made by this welder must be inspected.

5.23. Sections of the weld with unacceptable defects are subject to correction by local sampling and subsequent welding (without re-welding the entire joint), if the sample size after removing the defective section does not exceed the values ​​​​indicated in the table. 5.

Welded joints, in the seams of which, in order to correct the defective area, it is necessary to make a sample with dimensions larger than those allowed according to the table. 5 must be completely removed.

Table 5

Sampling depth % of the nominal wall thickness of welded pipes (calculated height of the seam section)	Length, % of the nominal outer perimeter of the pipe (nozzle)
St. 25 to 50	No more than 50
Note. When correcting several sections in one connection, their total length may exceed that indicated in the table. 5 no more than 1.5 times at the same depth standards.

5.24. Undercuts should be corrected by surfacing thread beads with a width of no more than 2.0 - 3.0 mm. Cracks must be drilled at the ends, cut out, thoroughly cleaned and welded in several layers.

5.25. All corrected areas of welded joints must be checked by external inspection, radiographic or ultrasonic flaw detection.

5.26. On the as-built drawing of the pipeline, drawn up in accordance with SNiP 3.01.03-84, the distances between welded joints, as well as from wells, chambers and user inputs to the nearest welded joints, should be indicated.

6. THERMAL INSULATION OF PIPELINES

6.1. Installation of thermal insulation structures and protective coatings must be carried out in accordance with the requirements of SNiP III-20-74 and this section.

6.2. Welded and flanged connections should not be insulated to a width of 150 mm on both sides of the connections before testing the pipelines for strength and tightness.

6.3. The possibility of carrying out insulation work on pipelines subject to registration in accordance with the Rules of the USSR Gosgortekhnadzor, before performing strength and tightness tests, must be agreed with the local body of the USSR Gosgortekhnadzor.

6.4. When performing flooded and backfill insulation during channelless laying of pipelines, the work design must include temporary devices to prevent the pipeline from floating up, as well as soil from getting into the insulation.

7. TRANSITIONS OF HEATING NETWORKS THROUGH DRIVEWAYS AND ROADS

7.1. Work at underground (aboveground) intersections of heating networks with railways and trams, roads, city passages should be carried out in accordance with the requirements of these rules, as well as SNiP III-8-76.

7.2. When piercing, punching, horizontal drilling or other methods of trenchless laying of casings, assembly and tack of casing links (pipes) must be performed using a centralizer. The ends of the welded links (pipes) must be perpendicular to their axes. Fractures of the axes of the links (pipes) of the cases are not allowed.

7.3. Reinforced shotcrete anti-corrosion coating of cases during trenchless installation should be made in accordance with the requirements of SNiP III-15-76.

7.4. Pipelines within the casing should be made from pipes of the maximum supplied length.

7.5. The deviation of the axis of the transition cases from the design position for gravity condensate pipelines should not exceed:

vertically - 0.6% of the length of the casing, provided that the design slope of the condensate pipelines is ensured;

horizontally - 1% of the length of the case.

The deviation of the axis of the transition casings from the design position for the remaining pipelines should not exceed 1% of the casing length.

8. TESTING AND WASHING (BLOWING) OF PIPELINES

8.1. After completion of construction and installation work, pipelines must be subjected to final (acceptance) tests for strength and tightness. In addition, condensate pipelines and pipelines of water heating networks must be washed, steam pipelines must be purged with steam, and pipelines of water heating networks with an open heating supply system and hot water supply network must be washed and disinfected.

Pipelines laid without channels and in non-passable channels are also subject to preliminary tests for strength and tightness during construction and installation work.

8.2. Preliminary tests of pipelines should be carried out before installing gland (bellows) compensators, sectional valves, closing channels and backfilling of channelless pipelines and channels.

Preliminary tests of pipelines for strength and tightness should be performed, as a rule, hydraulically.

At negative outside temperatures and the impossibility of heating water, as well as in the absence of water, it is allowed, in accordance with the work plan, to perform preliminary tests using a pneumatic method.

It is not allowed to carry out pneumatic tests of above-ground pipelines, as well as pipelines laid in the same channel (section) or in the same trench with existing utilities.

8.3. Pipelines of water heating networks should be tested at a pressure equal to 1.25 working, but not less than 1.6 MPa (16 kgf/sq.cm), steam pipelines, condensate pipelines and hot water supply networks - at a pressure equal to 1.25 working, unless other requirements justified by the project (working project).

8.4. Before performing strength and tightness tests, you must:

carry out quality control of welded joints of pipelines and correction of detected defects in accordance with the requirements of Section. 5;

disconnect the tested pipelines with plugs from the existing ones and from the first shut-off valves installed in the building (structure);

install plugs at the ends of the tested pipelines and instead of stuffing box (bellows) compensators, sectional valves during preliminary tests;

provide access along the entire length of the tested pipelines for their external inspection and inspection of welds during the tests;

open the valves and bypass lines completely.

The use of shut-off valves to disconnect the pipelines under test is not permitted.

Simultaneous preliminary tests of several pipelines for strength and tightness may be carried out in cases justified by the work design.

8.5. Pressure measurements when testing pipelines for strength and tightness should be made using two duly certified (one control) spring pressure gauges of class not lower than 1.5 with a body diameter of at least 160 mm and a scale with a nominal pressure of 4/3 of the measured pressure.

8.6. Testing of pipelines for strength and tightness (density), their purging, washing, disinfection must be carried out according to technological schemes(agreed with operating organizations), regulating the technology and safety precautions for carrying out work (including the boundaries of security zones).

8.7. Reports on the results of tests of pipelines for strength and tightness, as well as on their flushing (purging) should be drawn up in the forms given in mandatory appendices 2 and 3.

Hydraulic tests

8.8. Pipeline testing should be carried out in compliance with the following basic requirements:

test pressure must be provided at the top point (mark) of the pipelines;

the water temperature during testing must be no lower than 5 degrees C;

if the outside air temperature is negative, the pipeline must be filled with water at a temperature not exceeding 70 degrees C and it must be possible to fill and empty it within 1 hour;

when gradually filling with water, air must be completely removed from the pipelines;

the test pressure must be maintained for 10 minutes and then reduced to operating pressure;

at operating pressure, the pipeline must be inspected along its entire length.

8.9. The results of hydraulic tests for the strength and tightness of the pipeline are considered satisfactory if during the tests there was no pressure drop, no signs of rupture, leakage or fogging were found in the welds, as well as leaks in the base metal, flange connections, fittings, compensators and other pipeline elements , there are no signs of shifting or deformation of pipelines and fixed supports.

Pneumatic tests

8.10. Pneumatic tests should be carried out for steel pipelines with a working pressure not higher than 1.6 MPa (16 kgf/sq.cm) and a temperature of up to 250 degrees C, mounted from pipes and parts tested for strength and tightness (density) by the manufacturers in accordance with GOST 3845-75 (in this case, the factory test pressure for pipes, fittings, equipment and other products and parts of the pipeline must be 20% higher than the test pressure adopted for the installed pipeline).

The installation of cast iron fittings (except for valves made of ductile cast iron) is not allowed during testing.

8.11. Filling the pipeline with air and increasing the pressure should be done smoothly at a speed of no more than 0.3 MPa (3 kgf/sq.cm) per hour. Visual inspection of the route [entry into the security (dangerous) zone, but without descending into the trench] is allowed when pressure equal to 0.3 test, but not more than 0.3 MPa (3 kgf/sq.cm).

During the inspection of the route, the pressure rise must be stopped.

When the test pressure value is reached, the pipeline must be maintained to equalize the air temperature along the length of the pipeline. After equalizing the air temperature, the test pressure is maintained for 30 minutes and then smoothly decreases to 0.3 MPa (3 kgf/sq.cm), but not higher than the operating pressure of the coolant; At this pressure, pipelines are inspected and defective areas are marked.

Leak locations are determined by the sound of leaking air, bubbles when covering welded joints and other places with soap emulsion and the use of other methods.

Defects are eliminated only when the excess pressure is reduced to zero and the compressor is turned off.

8.12. The results of preliminary pneumatic tests are considered satisfactory if during their conduct there is no drop in pressure on the pressure gauge, no defects are found in welds, flange connections, pipes, equipment and other elements and products of the pipeline, and there are no signs of shift or deformation of the pipeline and fixed supports.

8.13. Pipelines of water networks in closed heat supply systems and condensate pipelines should, as a rule, be subjected to hydropneumatic flushing.

Hydraulic flushing with reuse of flushing water by passing it through temporary mud traps installed along the flow of water at the ends of the supply and return pipelines is allowed.

Washing, as a rule, should be done with technical water. Washing with household and drinking water is allowed with justification in the work project.

8.14. Pipelines of water networks of open heating systems and hot water supply networks must be flushed hydropneumatically with potable water until the flushing water is completely clarified. After flushing, the pipelines must be disinfected by filling them with water containing active chlorine at a dose of 75-100 mg/l with a contact time of at least 6 hours. Pipelines with a diameter of up to 200 mm and a length of up to 1 km are permitted, in agreement with local sanitary authorities. epidemiological service, do not chlorinate and limit yourself to washing with water that meets the requirements of GOST 2874-82.

After washing, the results of laboratory analysis of wash water samples must comply with the requirements of GOST 2874-82. The sanitary and epidemiological service draws up a conclusion on the results of washing (disinfection).

8.15. The pressure in the pipeline during flushing should not be higher than the working pressure. The air pressure during hydropneumatic flushing should not exceed the operating pressure of the coolant and be no higher than 0.6 MPa (6 kgf/sq.cm).

Water velocities during hydraulic flushing must be no lower than the calculated coolant velocities indicated in the working drawings, and during hydropneumatic flushing - exceed the calculated ones by at least 0.5 m/s.

8.16. Steam lines must be purged with steam and discharged into the atmosphere through specially installed purge pipes with shut-off valves. To warm up the steam line before purging, all start-up drains must be open. The heating rate should ensure that there are no hydraulic shocks in the pipeline.

The steam velocities when blowing each section must be no less than the operating velocities at the design parameters of the coolant.

9. ENVIRONMENTAL PROTECTION

9.1. When constructing new, expanding and reconstructing existing heating networks, environmental protection measures should be taken in accordance with the requirements of SNiP 3.01.01-85 and this section.

9.2. It is not allowed without agreement with the relevant service: to carry out excavation work at a distance of less than 2 m to tree trunks and less than 1 m to bushes; moving loads at a distance of less than 0.5 m to tree crowns or trunks; storing pipes and other materials at a distance of less than 2 m from tree trunks without installing temporary enclosing (protective) structures around them.

9.3. Hydraulic flushing of pipelines should be done by reusing water. Emptying of pipelines after washing and disinfection should be carried out in places specified in the work project and agreed upon with the relevant services.

9.4. Territory construction site after completion of construction and installation work, it must be cleared of debris.

Appendix 1. ACT ON STRETCHING OF COMPENSATORS

ANNEX 1
Mandatory

________________________ "_____"_________________19_____

Commission consisting of:

(last name, first name, patronymic, position)

_____________________________________________________________,

1. The extension of expansion joints listed in the table in the area from chamber (picket, shaft) No. _______ to chamber (picket, shaft) No. _______ was presented for inspection and acceptance.

Compensator number	Drawing number	Type of compensation	Stretch value, mm		Temperature outdoor
according to drawing			design	actual	air, degrees C

2. The work was carried out according to design estimates ____________

_______________________________________________________________

COMMISSION DECISION

The work was carried out in accordance with design and estimate documentation, state standards, building codes and rules and meet the requirements for their acceptance.

(signature)

(signature)

Appendix 2. ACT ON TESTING PIPELINES FOR STRENGTH AND TIGHTNESS

APPENDIX 2
Mandatory

_____________________ "_____"____________19____

Commission consisting of:

representative of the construction and installation organization _________________

_____________________________________________________________,
(last name, first name, patronymic, position)

representative of the customer's technical supervision _____________________

_____________________________________________________________,
(last name, first name, patronymic, position)

representative of the operating organization ______________________________

_____________________________________________________________
(last name, first name, patronymic, position)

inspected the work performed by ___________________________

_____________________________________________________________,
(name of construction and installation organization)

and drew up this act as follows:

1. ________________ are presented for inspection and acceptance

_____________________________________________________________
(hydraulic or pneumatic)

pipelines tested for strength and tightness and listed in the table, in the section from chamber (picket, shaft) No. ________ to chamber (picket, shaft) No. _________ route ___________

Length __________ m.
(name of pipeline)

Pipeline	Test pressure MPa (kgf/sq.cm)	Duration, min	External inspection at pressure, MPa (kgf/sq.cm)

2. The work was carried out according to design and estimate documentation __________________

_____________________________________________________________________
(Name design organization, drawing numbers and date of their preparation)

COMMISSION DECISION

Representative of the construction and installation organization ________________
(signature)

Representative of the customer's technical supervision _____________________
(signature)

(signature)

Appendix 3. ACT ON WASHING (BLOWING) OF PIPELINES

APPENDIX 3
Mandatory

_______________________________________ "_____"_______________19_____

Commission consisting of:

representative of the construction and installation organization ________________

_____________________________________________________________,
(last name, first name, patronymic, position)

representative of the customer's technical supervision _____________________

_____________________________________________________________,
(last name, first name, patronymic, position)

representative of the operating organization _____________________

_____________________________________________________________
(last name, first name, patronymic, position)

inspected the work performed by ____________________________

_____________________________________________________________,
(name of construction and installation organization)

and drew up this act as follows:

1. Flushing (purging) of pipelines in the section from chamber (picket, shaft) No. __________ to chamber (picket, shaft) No.______ of the route ________________________________________________________________________________ is submitted for inspection and acceptance.

_____________________________________________________________________________________
(name of pipeline)

length ___________ m.

Washing (purging) completed________________________________

_____________________________________________________________.
(name of medium, pressure, flow)

2. The work was carried out according to design estimates _________________

____________________________________________________________________

_____________________________________________________________________.
(name of the design organization, drawing numbers and date of their preparation)

COMMISSION DECISION

The work was carried out in accordance with design and estimate documentation, standards, building codes and regulations and meets the requirements for their acceptance.

Representative of the construction and installation organization ________________
(signature)

Representative of the customer's technical supervision _____________________
(signature)

Representative of the operating organization _____________________
(signature)

The text of the document is verified according to:
official publication
M.: CITP Gosstroy USSR, 1986

There are 4 types of testing of heating networks:

1. For strength and tightness (crimping). Performed at the manufacturing stage before applying insulation. When used annually.
2. At design temperature. Carried out: to check the operation of compensators and fix their working position, to determine the integrity of fixed supports (1 time every 2 years). Tests are carried out during the manufacture of networks before applying insulation.
3. Hydraulic. They are carried out to determine: the actual water consumption of consumers, the actual hydraulic characteristics of the pipeline and to identify areas with increased hydraulic resistance (once every 3-4 years).
4. Thermal tests. To determine actual heat losses (once every 3-4 years). Tests are carried out according to the following dependence:

Q = cG(t 1 - t 2) £ Q norms = q l *l,

where q l is the heat loss of 1 m of pipeline, determined according to SNiP “Thermal insulation of pipelines and equipment”.

Heat losses are determined by the temperature at the end of the section.

Strength and tightness tests.

There are 2 types of tests:

1. Hydraulic.
2. Pneumatic. Checked at t n<0 и невозможности подогрева воды и при её отсутствии.

Hydraulic tests.

Instruments: 2 pressure gauges (working and control) class higher than 1.5%, pressure gauge diameter not lower than 160 mm, scale 4/3 of the test pressure.

Order of conduct:

1. Disconnect the test area with plugs. Replace the stuffing box expansion joints with plugs or inserts. Open all bypass lines and valves unless they can be replaced with plugs.
2. The test pressure is set = 1.25 P slave, but not more than the working pressure of the pipeline P y. Exposure 10 minutes.
3. The pressure is reduced to operating pressure, and inspection is carried out at this pressure. Leaks are monitored by: pressure drop on the pressure gauge, obvious leaks, characteristic noise, fogging of the pipe. At the same time, the position of the pipelines on the supports is monitored.

Pneumatic tests It is prohibited to carry out for: Overhead pipelines; When combined with other communications.

During testing, it is prohibited to test cast iron fittings. It is allowed to test fittings made of ductile cast iron at low pressures.

Instruments: 2 pressure gauges, pressure source - compressor.

1. Filling at a rate of 0.3 MPa/hour.
2. Visual inspection at pressure P ≤ 0.3P tested. , but not more than 0.3 MPa. R use = 1.25 R work.
3. The pressure rises to P tested, but not more than 0.3 MPa. Exposure 30 min.
4. Reducing pressure to P slave, inspection. Leaks are determined by the following signs: a decrease in pressure on pressure gauges, noise, bubbling of a soap solution.

Safety precautions:

• during the inspection it is prohibited to go down into the trench;
• Do not get exposed to air flow.

Design Temperature Tests

Heat networks with d ≥100mm are tested. In this case, the design temperature in the supply pipeline and in the return pipe should not exceed 100 0 C. The design temperature is maintained for 30 minutes, while the increase and decrease in temperature should not be more than 30 0 C / hour. This type of test is carried out after the networks have been pressure tested and breaks have been eliminated.

Tests to determine thermal and hydraulic losses

This test is carried out on a circulation circuit consisting of supply and return lines and a jumper between them, all branches of the branch are disconnected. In this case, the decrease in temperature along the ring is caused only by heat losses of the pipelines. The test time is 2t to + (10-12 hours), t to is the travel time of the temperature wave along the ring. Temperature wave - an increase in temperature by 10-20 0 C above the test temperature along the entire length of the temperature ring, is established by observers and the temperature change is recorded.

The test for hydraulic losses is carried out in two modes: at maximum flow and 80% of the maximum. For each mode, at least 15 readings must be taken with an interval of 5 minutes.