RD 26-12-29-88

Group T58

GUIDANCE DOCUMENT

RULES FOR CONDUCTING PNEUMATIC TESTS OF PRODUCTS FOR STRENGTH AND TIGHTNESS

Date of introduction 1989-07-01

INFORMATION DATA

1. DEVELOPED AND INTRODUCED BY VNIIkompressormash

CONTRACTORS:

B.G. Shchebetenko (head of development);

N.D. Fedorenko, Cand. tech. sciences; N.V. Konygin; B. I. Ogurtsov, Cand. tech. sciences; G.V. Lysenko; V.I. Strelets; V.I. Chigrin; T.A. Pererva; V.G. Kontsevich; V. I. Zozulya, Cand. tech. sciences; N.A. Torgacheva.

2. APPROVED by the Main Scientific and Technical Department of Minkhimmash.

3. PUT INTO ACTION by the letter of the Main Scientific and Technical Directorate of Minkhimmash dated 27.01.89 N 1-10-4 / 61.

4. INTRODUCED FOR THE FIRST TIME

5. REFERENCE REGULATORY AND TECHNICAL DOCUMENTS

	Number of item, sub-item, transfer, application In general, wherever possible and where installation is permitted, care should be taken not to install electrical equipment in hazardous locations where arcs, sparks, or surface heating may occur that could ignite an explosive atmosphere present. These products must be subject to a control certificate to provide a level of security equivalent to that of the standard protection regime. It is very important to note that even if, on an individual basis, any electrical equipment has the appropriate certificates, but is subsequently assembled and is part of a certain set or equipment, these certificates are invalid; if they are not installed in accordance with the standards, criteria, prescriptions and recommendations required for the installation area and type of materials selected by the manufacturer.
GOST 12.3.002-80 *
	Annex 1 Therefore, the dispenser manufacturer will provide a global certificate for each device, which includes certificates of conformity for each of the electrical components, as well as installation and testing in accordance with the standards and applicable codes. The plans will outline the application rules used to classify sites, as well as the choice of electrical materials installed in them. Cables that are mechanically protected or have galvanized steel wire reinforcement, their minimum cross-section can be 2.5 millimeters for power supplies; for lighting and control, must have a minimum cross-section of one square millimeter.

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* Within the territory of Russian Federation GOST 12.3.002-75 is in effect. Hereinafter. - Note from the manufacturer of the database.


This guideline document applies to the production processes of pneumatic tests for strength and tightness of chemical and petroleum engineering products by excess gas pressure under static loading and establishes the organization and procedure for carrying out work and General requirements safety during pneumatic tests, as well as to the design, placement and operation of stands, installations and structures intended for these purposes.

The document does not apply to tests of refrigeration equipment using refrigerants and to the process of filling products with refrigerants prior to these tests.

Terms and definitions used in this document are given in reference annex 1.

1. GENERAL PROVISIONS

1. GENERAL PROVISIONS

1.1. The need for pneumatic tests is established by the technical documentation for a specific product.

1.2. When developing technological processes for pneumatic tests for strength and tightness, when designing test stands, sections and housings, during the manufacture, installation and operation of technological systems, tooling, equipment and protective devices, along with the requirements of this document, the requirements of the current state labor safety standards ( SSBT), sanitary, building codes and regulations and other regulatory documents on labor safety.

1.3. The responsibility for the completeness of the statement of safety requirements in the design and technological documentation, the quality of manufacture, as well as the good condition and safe operation of test stands and protective devices are borne by enterprises and organizations performing the relevant work.

1.4. Normative and technical documents for test methods must contain safety requirements, which must be specific and reflect the specifics of testing products for strength and tightness.

1.5. Responsible for the creation of safe working conditions during pneumatic tests is the head of the enterprise, the head of the shop, the senior foreman and the foreman - the direct supervisor of the tests, appointed by the order of the shop.

1.6. Responsibility for violation of safety rules is assigned to: the head of the shop, senior foreman, foreman (head of tests), who do not provide safe working conditions, and on testers who violated safety rules.

2. INITIAL DATA FOR PURPOSING PNEUMATIC TESTS

2.1. Pneumatic tests of products are assigned in order to:

1) checking the tightness of products for preliminary determination of leaks before using highly sensitive control methods, as well as for acceptance control, if this method meets the requirements for operating the product, and the use of other methods of tightness control provided for by GOST 24054-80 is impractical or unacceptable for technical reasons;

2) checking the strength of products - in exceptional cases when it is impossible or irrational to conduct hydraulic tests (industrial use of the product does not allow the presence of even traces of moisture; the design of the product is not suitable for filling with water; static loads when filling the product with water are unacceptable due to the strength of the product, supporting structures and foundation).

2.2. The necessity or admissibility of pneumatic strength tests, as well as methods of monitoring and assessing tightness, are established by the design documentation for a specific product.

2.3. Pneumatic tests can be provided for products intended for operation under atmospheric pressure, under filling, under vacuum and under internal overpressure.

2.4. In pneumatic strength tests, air (up to 63.0 MPa) should be mainly used as the working gas.

When testing for tightness, in justified cases, other gases can be used, including those on which the product is operated.

2.5. Leak detection and its assessment at pneumatic tests products under the conditions of production and installation are made by the following methods:

1) manometric, based on the registration of changes in gas pressure over a certain period of time, taking into account the change in gas temperature;

2) gas leakage into the cavity of the product adjacent to the test;

3) bubble, in which gas bubbles are recorded escaping from the product placed in water (in justified cases, in another liquid);

4) soaping;

5) acoustic leak detection based on the indication of ultrasonic acoustic waves excited when gas flows through through pores and slots.

2.6. The sensitivity of tightness control by pneumatic tests is estimated by the amount of gas leakage depending on its pressure per second, m MPa / s (m Pa / s), and is for control methods:

1) gauge - up to 1 · 10 (1 · 10);

2) bubble (air in water) up to 1 · 10 (1 · 10);

3) soaping - up to 5 · 10 (5 · 10);

4) acoustic - up to 1 · 10 (1 · 10);

2.7. The value of gas pressure during pneumatic strength tests must correspond to the value of pressure during hydraulic tests, assigned in accordance with applicable rules and regulations.

2.8. The value of gas pressure during pneumatic tightness tests should be taken for products:

1) working under atmospheric pressure - 0.01 (0.1) MPa (kgf / cm);

2) working under loading - equal to the working hydrostatic pressure;

3) working under vacuum - 0.1 (1.0) MPa (kgf / cm);

4) working under excess pressure - equal to the working pressure during operation, but not higher than the calculated one.

2.9. Products intended for operation under internal overpressure of gas before pneumatic tightness tests, as a rule, must undergo a strength test by hydraulic pressure.

2.10. For products with a design (working) pressure of up to 10 MPa (100 kgf / cm), in cases of inadmissibility of clogging of leaky places with water, suspended particles or corrosion products, it is allowed to conduct pneumatic tightness tests before conducting hydraulic tests.

In this case, the gas pressure should not exceed 10% of the calculated (working).

3. DANGEROUS FACTORS IN PNEUMATIC TESTS

3.1. In the process of pneumatic tests, the main danger is the energy accumulated in the system, the value of which is several orders of magnitude greater than during hydraulic tests.

3.2. During pneumatic strength tests, both sudden depressurization of detachable joints and destruction of the tested product (rupture, separation of elements, etc.) are possible, as a result of which the following dangerous and harmful factors arise:

1) shock wave;

2) fragments of the product and equipment;

3) a sharp increase in pressure the environment in the test area.

The destruction of the product during pneumatic tests is of an emergency nature.

3.3. During pneumatic tightness tests, a sudden depressurization of the detachable connections of the product or systems with compressed gas is possible, as a result of which the following dangerous and harmful factors can arise:

1) elements of detachable joints of a product, tooling and systems moving at high speed under the influence of pressure or a flowing jet;

2) increased noise level, including when safety devices are triggered;

3) swarf, scale, dust, increased by a gas jet, etc .;

4) increased gas contamination of the working area when using compressed gases other than air for testing.

3.4. The degree of hazard of products under gas pressure, both during strength tests and during tightness tests, is assessed by the following characteristics:

1) the value of the test pressure, kgf / cm;

2) energy consumption of compressed gas, kgf / cml,

where is the volume of the internal space (capacity) of the product, l.

4. REQUIREMENTS FOR DESIGN, ORGANIZATION AND PERFORMANCE OF PNEUMATIC TESTS

4.1. Test Process Design Requirements

4.1.1. Responsible for the development of the pneumatic test technological process, which ensures the safety of the test, is the department - the developer of the technological process.

4.1.2. Pneumatic strength tests should be carried out using protective devices, the characteristics of which and design features are given in Appendix 2.

Recommendations for the use and placement of protective armored devices are given in Appendix 3.

4.1.3. The definition of the radius of the hazardous area during pneumatic strength tests of products carried out in open areas is given in Appendix 4.

4.1.4. Without the use of protective devices at the production site, any products can be tested for strength by excess pressure of air, nitrogen or helium up to 0.1 MPa (1.0 kgf / cm).

4.1.5. Pneumatic tightness tests of products that have passed strength tests, as well as products in accordance with clause 2.10, are recommended to be carried out using the protective devices given in Appendix 5.

4.1.6. At the production site, without the use of protective devices, it is allowed to carry out pneumatic tightness tests with air, nitrogen or helium:

1) products with a volume of not more than 100,000 liters, tested for strength, if the test pressure for tightness does not exceed 0.2 MPa (2.0 kgf / cm);

2) erection joints and detachable joints of pipe products specified in table 1, provided that:

assembly units have been tested for strength,

there are no defects in the assembly joints during non-destructive testing,

the technological process of testing provides for safety requirements,

control over compliance with the test technological process is organized.

Table 1

Total energy consumption, kgf / cm l, no more	Test pressure, kgf / cm, no more	Diameter of pipelines with tested joints, mm, no more
		not limited

4.1.7. Pneumatic tests should be carried out in the temperature range of the ambient atmospheric air and the compressed gas used from plus 50 ° C to minus 40 ° C.

4.1.8. In justified cases, pneumatic testing of products for tightness can be carried out at a compressed gas and ambient temperature from minus 196 ° C to plus 200 ° C, safety requirements are established by special instructions.

4.1.9. Requirements for the quality of preparation of the product for testing, methods of fastening test fixtures and equipment, methods of fastening (installation, mounting) of the product, taking into account the most critical positions during testing and during operation, as well as test modes, should be specified in the technological process (instructions).

4.1.10. The strength of special equipment and fixtures used during testing should be confirmed by calculations and verified by tests. As a rule, the tightness test should use the same fixtures and fittings on which the product was tested for strength.

4.1.11. When carrying out strength tests, it is allowed to simulate the standard fastening of plugs and covers while maintaining the actual loading conditions of the product parts during operation.

When testing for tightness, it is allowed to use other structures for fastening the plugs, which ensure the safety of the tests.

4.2. Requirements for the organization and conduct of tests

4.2.1. The general management of the preparation and conduct of pneumatic tests should be carried out by the head of the tests (foreman, head of the laboratory, head of the site).

4.2.2. The stand (installation) for pneumatic testing in each shift must be assigned to the most qualified tester by the order of the shop.

4.2.3. Access to the controls of the test bench to another person is allowed by order of the head of the test, which should be reflected in the test log.

4.2.4. A minimum number of responsible executors, but not less than two, should serve the test stand during the testing process.

4.2.5. The following persons are allowed to be on the test bench, at the control panel and in the test area:

1) the head of the tests;

2) testers;

3) the controller;

4) the customer's representative.

The presence of unauthorized persons in the test area is allowed only with the permission of the head of the production unit.

4.2.6. The signal about the start of testing (gas supply to the tested item) is given by the tester after checking the readiness for testing.

He also gives a signal about the end or termination of the tests, making sure that there is no pressure in the tested product and the stand systems (after the locking device of the control panel).

Signaling by other persons other than testers is prohibited.

During the tests, the testers have no right to leave the control panel and the product under gas pressure unattended or be distracted for other work.

4.2.7. Simultaneously with the start of the tests, a light board should be switched on on the protective device: "Tests in progress" or "Product under pressure".

4.2.8. Before starting pneumatic tightness tests, the tester must make sure that the strength tests have been completed in full, as there is a record in the accompanying documentation, and the product is stamped with the strength test pressure.

4.2.9. During pneumatic tests, lifting and moving products under pressure is not allowed.

Allowed to lift within the test bench of the product together with a rigid frame, if this does not pass additional loading of the product.

4.2.10. It is forbidden to use any levers not provided for in the technical documentation to close the fittings and tighten the detachable connections.

4.2.11. On a product under excessive gas pressure, it is prohibited to tap, eliminate leaks and other malfunctions, connect and disconnect pipelines and hoses, tighten fasteners.

4.2.12. During pneumatic strength tests, the pressure in the product should be increased gradually, if necessary, with stops and inspections, until reaching:

1) 60% of the test pressure, if its value does not exceed 12.5 MPa (125 kgf / cm);

2) pressure of 10.0 MPa (100 kgf / cm), if the value of the test pressure is 20 MPa (200 kgf / cm) or more.

The rise in pressure must be temporarily stopped at each inspection of the product.

Further increase in pressure until reaching the test pressure should be raised with stops:

1) for products with a test pressure of less than 12.5 MPa (125 kgf / cm) - upon reaching 80% and 90% of the test pressure;

2) for products with a test pressure from 12.5 MPa (125 kgf / cm) to 50.0 MPa (500 kgf / cm) - upon reaching 60%, 80%, 90% and 95% of the test pressure;

3) for products with a test pressure above 50.0 MPa (500 kgf / cm) - upon reaching 60%, 80%, 85%, 90% and 95% of the test pressure and every subsequent 2.5 MPa (25 kgf / cm ).

The duration of the stops is at least 3 minutes. At the same time, access of people to the product or exit from the shelter is not allowed.

4.2.13. The test pneumatic pressure for strength must be maintained for 5 minutes, after which it is reduced to the working (calculated) pressure, at which the tightness tests are carried out.

4.2.14. In a pneumatic leak test of products that have passed hydraulic strength tests, the gas pressure in the product should be raised gradually with stops and inspections until the test pressure is reached.

Stops and inspections are recommended to be performed upon reaching the pressure levels given in paragraph 4.2.12.

The pressure build-up must stop during inspection.

The test pressure in the product is maintained for the period of detecting leaks or assessing the tightness of the product.

4.2.15. At the end of the identification of leaks, before their elimination and after the completion of tests, the excess pressure from the product must be dropped to zero.

4.2.16. Carrying out pneumatic tests should be controlled by the technical control of the manufacturer. The test results are drawn up and reflected in the documentation in the prescribed manner.

4.2.17. If during the pneumatic test:

1) there was a destruction of the tested product or its elements;

2) when compressed gas is supplied, the pressure in the tested product does not increase;

3) the indicating devices, safety valves and shut-off devices are out of order;

4) an alarm has been triggered;

5) the pressure in the product rises above the permitted one, despite the observance of all the requirements of the instructions;

6) a dangerous, harmful concentration of gas has been created in the room, then the tests must be stopped, the pipeline supplying compressed gas is shut off, the electricity is turned off, the gas pressure in the product is reset to zero.

4.3. Requirements for control systems and control of technological test processes

4.3.1 Boards and consoles for control and monitoring of test processes should be moved to a safe place.

4.3.2. On the control panels of test stands and installations with a complex circuit, a mnemonic diagram should be placed in a conspicuous place to facilitate control.

4.3.3. The main instruments in the pneumatic testing process are pressure and temperature control devices for compressed gas. All devices must comply with the requirements of the documentation establishing their accuracy.

Measuring devices must be verified in accordance with the requirements of GOST 8.002-86 *.
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* On the territory of the Russian Federation, PR 50.2.002-94 are in force. - Note from the manufacturer of the database.

4.3.4. The upper limits of the pressure gauge scales should be selected according to the value of the test pressures in the products in accordance with the current regulations.

table 2

Measured pressure, MPa (kgf / cm)			Accuracy class	Note
		up to 13.7 (140) incl.
				for electrical contact pressure gauges

4.3.6. It is prohibited to use pressure gauges with:

1) there is no seal or stamp with a mark on the verification;

2) the verification period has expired;

3) the arrow, when the pressure is completely released, does not return to the zero scale indicator by an amount exceeding half of the permissible error;

4) the glass is broken or there is damage that may affect the correctness of the readings.

4.3.7. The safety valves used during the test must be adjusted to full opening pressure in accordance with the regulations in force and sealed,

4.3.8. Pressure gauges and safety valves on the items under test should be installed in locations where accumulation of liquid is impossible.

5. REQUIREMENTS FOR ROOMS AND AREA FOR TEST STANDS

5.1. The construction of buildings and premises intended for the placement of stands and installations for pneumatic strength testing of products (a detached building, a building attached to a production building or an isolated area in a production building), in which mine-type armored chambers and armored boxes are placed, should be carried out in accordance with the design documentation developed by specialized organizations.

5.2. The creation of special isolated areas in the production building for stands with armored chambers on the floor of the room, intended for strength testing, should be carried out in accordance with the technological planning of the enterprise, developed taking into account the requirements of GOST 12.3.002-75, sanitary rules and this standard and agreed with the specialized organization.

5.3. Open areas on the territory of the enterprise, as well as stands for testing products for strength, located at the production site, where armored chambers and armored caps are used as protective devices, are created on the basis of technological layouts, agreed in accordance with the procedure established at the enterprise.

5.4. Walls, ceilings and partitions of all rooms in which the test stands are located must ensure complete localization of the propagation of the shock wave in the event of a rupture of the test item.

5.5. Detached and attached to production buildings, hulls with armored chambers and armored boxes should be equipped with knock-out elements that ensure weakening of the shock wave from the rupture of the test product and its propagation in the safest direction, as well as the release of the resulting excess pressure.

5.6. If there are weakened elements in the building (gates, light ceilings, windows, etc.), then a danger zone must be designated outside them.

5.7. Buildings, isolated production areas, armored boxes and armored chambers must be equipped with supply and exhaust ventilation.

The performance of general ventilation must ensure at least three exchanges per hour in the internal volume of the room.

5.8. Gas release systems from the tested product should be equipped with noise suppressing devices that reduce noise levels to the maximum permissible for industrial premises.

5.9. The room temperature must be maintained within the range from plus 15 to plus 25 ° C.

5.10. Emergency lighting should be provided in the room. The illumination created in this case should make it possible to carry out the necessary operations to terminate the tests or bring the tests to the end.

5.11. Air collectors and cylinders must be installed and stored in accordance with the requirements of the "Rules for the Design and Safe Operation of Pressure Vessels".

5.12. Compressors must be placed in accordance with the "Rules for the Design and Safe Operation of Compressor Units, Air Ducts and Gas Pipelines".

5.13. Hoisting mechanisms and cranes for servicing test stands must meet the requirements of the current "Rules for the construction and safe operation of hoisting cranes".

5.14. Electrical equipment must comply with the explosion and fire hazard classes of the premises.

6. REQUIREMENTS FOR TEST STANDS

6.1. The developer of the test bench project is responsible for the selection of the test setup scheme, protective devices, pneumatic systems, safety devices, materials, calculation of elements and assembly units, taking into account the requirements of SSBT.

6.2. A pneumatic test bench usually includes:

1) compressors;

2) air collectors for storing compressed air and cylinders for storing other gases;

3) pipelines and valves;

4) consoles and control panels with measuring instruments;

5) body armor;

6) lifting and transport devices, as well as devices for securing products.

In addition to the listed equipment providing the technological process of testing, the stand should include:

1) warning signaling (light, sound), fencing with barriers and warning signs;

2) devices for visual control of pressure in the product;

3) safety devices that exclude excess pressure in the product in the supply systems;

4) a system for venting gas from the product and the protective device after testing.

6.3. Stands and other technological equipment associated with the preparation and conduct of strength tests in production buildings in specially designated areas must ensure the safety of workers in adjacent production areas.

6.4. When designing, manufacturing, installing and operating all components of the test bench, in addition to the requirements of regulatory and technical documents, it is also necessary to be guided by the requirements below.

6.5. All purchased products used as part of the stand must have passports.

6.6. Air and gas supply of the stands should be carried out with air or gas dried and purified from mechanical impurities; the degree of dryness (dew point) is determined by the requirements for the product under test.

6.7. The fittings and pipelines for connecting the tested product to power systems and control panels must correspond to the value of the test pressure.

6.8. The high-pressure system must have a device that allows you to relieve pressure from air collectors (cylinders) and unload the reducers after testing.

6.9. To measure the test pressure, two pressure gauges of the same class should be provided - working and control.

A safety valve must be provided to protect against overpressure.

6.10. All tanks and pipelines of the stand must be rated for strength. The calculation is attached to the stand passport.

6.11. Pipeline connections must be manufactured in accordance with current standards.

The materials used for pipeline parts must comply with the requirements of standards and technical specifications.

6.12. Special fittings for stands (valves, valves, filters, etc.) should be used only of industrial production and have the appropriate technical documentation.

6.13. Tightening of threaded connections should be done only with standard wrenches; lengthening the key handle is not allowed.

6.14. The assembly units of pipelines arriving for the installation of the stand must be tested for strength and tightness. After installation, the piping system must also be tested for strength and tightness.

The stand is considered to have passed the test if no places of rupture, deformation, leaks and omissions are found.

The test results are documented in an act and entered in the stand passport.

6.15. The assembled test bench after the commissioning must be accepted into operation by the commission appointed by the order for the enterprise.

6.1.6. A passport must be issued for the test bench in accordance with Appendix 6 with the following documentation attached:

1) schematic diagram of the stand;

2) drawings of general types of control and protective device;

3) passports for vessels, units, protective devices, equipment;

4) information about the materials used for the design details;

5) strength calculations of elements working under pressure;

6) information on the welding of pipelines;

7) the act of making the stand in accordance with Appendix 7;

8) act of acceptance of the stand in operation in accordance with Appendix 8;

9) act of testing the protective device for strength.

6.17. Dangerous places of test benches should be provided with warning notices, color safety signs; the boundaries of the test areas should be fenced off or marked.

6.18. Equipment and tools used during testing should be stored in specially designated places.

6.19. Test benches must undergo scheduled preventive maintenance according to the schedules approved by the enterprise.

6.20. To supervise the good condition and safe operation of test benches, by order of the unit from the number of engineering and technical workers, the following should be appointed:

1) responsible for the safe operation of the test bench;

2) responsible for the good condition of the stand.

6.21. The person responsible for the safe operation of the test bench is responsible for monitoring and organizing:

1) correct operation of the equipment and systems of the stand;

2) training, timely briefing and re-certification of personnel;

3) personal protective equipment, devices; overalls and the correctness of their use;

4) compliance by workers with safety rules during the preparation and conduct of tests.

6.22. The duties of the person responsible for the good condition of the stand include:

1) monitoring the technical condition of the stand;

2) ensuring timely fulfillment of the scheduled preventive maintenance of equipment and systems of the stand;

3) organization and conduct of technical examination (certification);

4) entering in the passport of the test stand and instrumentation passports information about the inspections, tests, repairs, replacement of units, etc.

6.23. Technical examination of test benches must be carried out at least once every three years; it is carried out under the guidance of the person responsible for the good condition of the stand.
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For pneumatic testing, the pressure inside gas pipelines, oil and oil product pipelines is created with air or natural gas. As sources of compressed air, mobile compressor units are used, which, depending on the volume of the cavity of the test area and the magnitude of the test pressure, are used one at a time or combined into groups. The time for filling the pipeline with air can be determined from the nomogram of the recommended app. 1. Natural gas for testing pipelines should be supplied from a well (for field pipelines only) or from existing gas pipelines crossing or directly adjacent to the construction site. The pressure during pneumatic strength test of the pipeline as a whole at the last stage should be equal to 1.1 R slave, and the duration of holding under this pressure is 12 hours. The graph of the pressure change in the pipeline during pneumatic testing is shown in Fig. 11. Filling the pipeline with air or natural gas is carried out with inspection of the route at a pressure equal to 0.3 of the strength test, but not higher than 2 MPa (20 kgf / cm 2). During pumping, an odorant should be added to natural gas or air to facilitate subsequent pipeline leak detection. To do this, it is necessary to install installations for dosing odorant at the nodes of connection to gas or air sources. The recommended rate of odorization with ethyl mercaptan is 50-80 g per 1000 m 3 of gas or air. If a leak is found during inspection of the route or in the process of raising the pressure, the supply of air or gas to the pipeline should be stopped immediately, after which the possibility and expediency of further testing or the need to bypass air or gas to an adjacent section should be established.

Rice. 11. Graph of pressure change in the pipeline during pneumatic test:

1 - pressure rise; 2 - pipeline inspection; 3 - test of endurance; 4 - pressure relief; 5 - check for tightness.

Inspection of the route with an increase in pressure from 0.3 R isp before R isp and the duration of the strength test is prohibited. After the end of the pipeline strength test, the phenomenon must be reduced to the design worker and only after that a control inspection of the route should be performed to check for leaks. When depressurizing, air or gas should be bypassed to adjacent areas if possible. Considering that, during pneumatic testing, the processes of filling the pipeline with natural gas and air up to the test pressure take a long time, it is necessary to pay special attention to the rational use of the energy accumulated in the pipeline by repeated bypassing and pumping natural gas or air and. tested areas to areas to be tested. To prevent gas or air losses in case of ruptures, filling the pipeline with a pressure medium and raising the pressure to the test pressure must be carried out along the bypass lines with closed linear valves.