Gas Supply Project of Tonar Boiler House plus Kalinina, 30/7 Barnaul

Contents

Introduction

1. Source Data

2. General Information

3. Acceptance, commissioning of gas pipelines

3.1 Commissioning, technical documentation

3.2 Commissioning

3.3 Tests

3.4 Gas pressure measurement in gas distribution networks

4. Maintenance

4.1 Route Bypass

4.2 Technical survey of gas pipelines

4.3 Operational and technical documentation

5. Maintenance and overhaul

5.1 Maintenance

5.2 Overhaul

6. Emergency dispatch maintenance of gas distribution systems

6.1 General Instructions

6.2 Localization and elimination of accidents and emergency situations

6.3 Dispatch control of gas distribution systems

6.4 Typical Accident Localization and Response Plans

6.5 List of ADF equipment with material and technical means

7. Occupational Safety Requirements

8. Fire safety requirements

9. Operation Work Schedule

Literature

Appendix A

Appendix B

Appendix B

Introduction

The operation of gas pipelines and gas equipment in cities and settlements is carried out by specialized gas enterprises. Their main tasks are: uninterrupted, reliable and economical gas supply to consumers, maintaining the necessary pressures in gas networks, timely detection and elimination of damage to gas pipelines and installations, acceptance of built gas pipelines and their commissioning.

The structure of the organization of operation of the gas farm depends on the scope of work and the amount of gas sold. Therefore, in large cities, management or trusts are in charge of operation, and in small cities and rural settlements - offices or sections of the gas economy led by regional gas management departments. The main subdivisions of these operating organizations are underground gas pipelines, internal gas equipment and emergency dispatch service [2].

Service of underground gas pipelines and structures. The main tasks of the service are: organization of work to ensure uninterrupted and accident-free operation of underground gas pipelines and structures on them.

The Service provides technical supervision over the construction of networks and structures on them, acceptance for operation of completed gas pipelines; development of plans and schedules for maintenance, maintenance and overhaul of gas pipelines, performance of works in accordance with plans and schedules; execution of works on connection of newly built and overhauled gas pipelines to the existing and gas start-up; bypass of gas pipelines routes, FRG; execution of works to eliminate blockages and accidents in gas pipelines; organization and execution of gas hazardous works, etc. [3]

1. Source data.

The construction of an underground gas pipeline is carried out for the gas supply of the boiler base "ID Altapress" LLC along the street Radishcheva, 1B in Barnaul.

Gas pipeline material steel electric welded pipes as per GOST 1070491; diameter - 57 * 3.5; depth of laying - 1.1 m.

57х3.5 projects "The gas pipeline of high pressure to CJSC SDLPlyus base on st. the Right bank of a pond, 86" pressure of 0.5 MPas crash into a functioning gas pipeline of high pressure (high pressure 2 categories) and passes podzemno to GGRP (depth of laying of 1.38 - 1.9 m).

The climate of the construction area, sharply continental with cold long winters and warm summers.

The soils of the base of the gas pipeline pipes are light solid loam. The normative depth of seasonal freezing of loam is 1.9 m. According to the degree of danger of frosty bulging, loam is almost unpowered.

2. General Information

Natural gas is produced in gas fields, which consist of production wells, field gas collection networks and head facilities for preparing gas for further transportation.

Natural gas supply from gas wells to the place of its consumption is produced through main gas pipelines. The main gas pipeline is a complex structure consisting of gas pipelines, gas purification and drying units, compressor and gas distribution stations and odorisation units.

Pipes of diameter 1220 mm and 1420 mm are used to transport large amounts of gas through gas main lines, working pressure is increased to 7.5 MPa, gas pipelines are laid in two threads or more.

Gas distribution stations (GRS) are built on the way to the city, from which gas, after measuring its amount and reducing pressure, is supplied to the distribution networks of the city. The gas distribution station is the final section of the main gas pipeline and is, as it were, the border between the city and main gas pipelines.

Depending on the maximum working gas pressure, gas pipelines are divided into low-pressure gas pipelines - up to 0.005 MPa; average - over 0.005 to 0.3 MPa; high pressure - more than 0.3 to 1.2 MPa.

Low-pressure gas pipelines are designed to supply gas to residential and public buildings, as well as utility consumers.

Medium-pressure gas pipelines serve to supply low-pressure distribution gas pipelines through FRG, and also supply gas to gas pipelines of industrial and municipal enterprises.

Gas flows through high-pressure gas pipelines for urban gas control points, local GRP of large enterprises, as well as enterprises whose technological processes require the use of high-pressure gas (up to 1.2 MPa). Gas pipelines of different pressures are interconnected through gas control points.

The gas supply system should ensure uninterrupted gas supply to all consumers, be simple, convenient and safe to maintain, provide for the possibility of disconnecting its individual elements for emergency and repair work.

According to the number of pressure stages used in gas networks, gas supply systems are divided into: single-stage with the supply of gas to various consumers only through gas pipelines of one pressure; two-stage with two-pressure gas pipeline to consumers - medium and low, high and low, high and medium; three-stage with the supply of three pressures to consumers through gas pipelines - low, medium and high (up to 0.6 MPa); multistage with supply of low, medium and high (up to 0.6 MPa and up to 1.2 MPa) pressures to consumers through gas pipelines. The multi-stage system is used for gas supply to large cities.

Gas supply systems of cities and settlements can be dead end, ring, mixed.

Dead end gas pipelines branch in various directions to gas consumers. These schemes are used for intra-quarter and yard gas pipelines in small settlements, as well as in the initial period of gasification.

Ring networks are a system of closed gas pipelines, due to which a more uniform gas pressure regime is achieved for all consumers and various repair and operation work is facilitated (compared to dead end gas pipelines).

The mixed gas supply system consists of annular gas pipelines and dead end gas pipelines connected to them [3].

3. Acceptance, commissioning of gas pipelines

3.1 Commissioning, technical documentation

After completion of construction and installation works, the construction organization presents the gas pipeline for delivery. When gas pipelines are accepted by the customer, an acceptance commission is created.

1. The acceptance committee includes representatives of the customer (chairman of the commission), design and operating organizations. Representatives of the bodies of the State Gortekhnadzor of Russia are included in the acceptance commission when accepting objects controlled by these bodies.

2. The General Contractor shall submit the following as-built documentation to the acceptance commission for the completed construction of the gas distribution system facility in one copy:

- set of working drawings (as-built geodetic documentation as per GOST R 51872) for construction of the object presented for acceptance with inscriptions made by persons responsible for construction and installation works, on compliance of works performed in kind with these drawings or changes made to them by the design organization;

- certificates of manufacturers (their copies, extracts from them, certified by the person responsible for the construction of the facility) for pipes, shaped parts, welding and insulation materials;

- technical passports of manufacturers (procurement workshops) or their copies for equipment, units, connectors, insulation coatings, insulating flanges, fittings with a diameter of more than 100 mm, as well as other documents certifying the quality of equipment (products);

- manufacturer's instructions on operation of gas equipment and instruments;

- construction passports: external gas pipeline, gas input; indoor (indoor) gas equipment; FRG;

- report of inspection of gas pipeline welded joints by radiographic method; ultrasonic inspection report of gas pipeline welded joints and quality inspection report of joints made by contact welding and soldering;

- act of breakdown and transfer of route (site) for underground gas pipeline;

- work log (for underground gas pipelines with a length of more than 200 m) - at the request of the customer;

- certificates of acceptance of hidden and special works performed in accordance with the contract (contract) - for GRP, boiler houses;

- technical certificate for imported materials and technologies used in construction.

3. The acceptance commission shall check compliance of the installed gas distribution system with the design and the submitted as-built documentation with the requirements of SNiP 42012002 [4].

4. Acceptance by the customer of the gas distribution system completed by the construction of the facility shall be executed by an act according to the form of mandatory appendix A. This act confirms the fact of creation of the facility and its compliance with the project and the mandatory requirements of regulatory documents. It is final for a separately erected gas distribution system facility.

Acceptance by the customer of the gas distribution system facility completed by construction may be carried out in accordance with the requirements of territorial construction standards (TSN) for acceptance, approved in the established order. [4]

3.2 Commissioning [1]:

1. Work on gas pipelines tie-in and gas start-up is carried out by the personnel of the operational organization.

Earthworks and insulation works at the attachment point shall be performed by the construction and installation organization. A section of the gas pipeline at the point of tie-in is filled with sand to a height of at least 20 cm from the upper generatrix of the pipe, carefully knocking out the sinuses.

Work on the tie-in of gas pipelines and gas start-up on the on-site gas pipelines of enterprises is allowed to be carried out by the team of the gas service of the enterprise.

2. Work on gas pipelines tie-in and gas start-up is carried out by start-up teams consisting of at least three people with the necessary tools, devices and personal protective equipment, under the guidance of a specialist (foreman).

3. Gas pipelines tie-in and start-up shall be performed according to permits for gas hazardous works (Annex B) and, if necessary, according to the work organization plan approved in accordance with the established procedure, agreed with ADF.

4. In preparation for work, it is necessary to:

• check and prepare the necessary technical documentation (as-built - for the connected gas pipeline);

• inspect the connected gas pipeline, disconnecting devices, connection point, pit (trench, pit) for work. If defects are detected, perform the work after their elimination;

• Develop (if necessary) a work plan and notify the organizations involved in the work and ADF;

• prepare tools, mechanisms, accessories, materials, instruments, check their suitability for use;

• fabricate connection units;

• ensure availability of the necessary vehicles, compressor;

• obtain work permits for gas hazardous works.

5. The Work Plan contains:

• connection node diagram;

• Process sequence for control pressure testing, gas pipeline tie-in and gas blowing;

• The procedure and conditions for disconnecting gas or reducing its pressure in the existing gas pipeline;

• procedure for gas blowing of the connected gas pipeline according to the scheme, which indicates branches and places of installation of hydraulic locks, condensate collectors, disconnecting devices, pressure gauges, plugs, blowdown candles;

• numerical and qualified staff of workers and specialists;

the need for transport, machinery, devices, instruments, materials;

• security measures;

The work organization plan may provide for the execution of separate work permits for gas hazardous works.

6. Gas consumers shall be notified of the time of the tie-in works related to the gas supply termination or reduction of its pressure not later than 3 days before the start of the works.

7. Before tapping into an active gas pipeline, the connected gas pipeline should be checked for tightness by air pressure testing at a pressure of 0.02 MPa. The pressure drop shall not exceed 10 daPa per 1 hour.

The results of pressure testing are recorded in the work permit. The air pressure in the connected gas pipeline shall be maintained until the start-up of the gas.

If there is excess pressure in the connected gas pipeline and gas start-up not later than 6 months from the date of its commissioning, it is allowed not to perform control pressure testing.

8. Persons involved in the performance of work shall be instructed about the sequence of technological operations and tasks of each team member, safety measures and the use of personal protective equipment.

9. The Tie-in Manager shall check the following before commencing work:

• air pressure in the connected gas pipeline;

• presence of blankings and closing of gate valves in wells (tightening bolts on gas pipeline compensators must be removed);

• presence of a plug at the end of each connected gas pipeline (if there is a disconnecting device at the end of the gas pipeline, the plug must be installed downstream of it);

• disconnection of gas inlets to the building from internal gas pipelines and presence of plugs after disconnecting devices;

• organization of ventilation of pits (pits) for tie-in;

• preparation of tie-in place (insulation cleaning and marking);

• installation of pressure gauges and blowdown candles. Valves on blowdown candles shall be closed;

• performance of safety measures during works;

10. In case of tie-ins with reduction of gas pressure in the operating gas pipeline, pressure reduction and its adjustment in the limits required by the tie-in technology is carried out by gas discharge through blowdown plugs installed on the operating GRP and gas pipeline.

The value of the gas pressure in the operating gas pipeline should be checked during the entire time of work by pressure gauges. If the gas pressure in the existing gas line drops below 40 dPa or rises above 200 dPa, the operation must be stopped before the gas pressure is restored.

11. During gas start-up the gas pipeline is blown by gas through blowdown plugs installed on the connected gas pipeline (on condensate collectors, hydraulic locks, at the endpoints of the gas pipeline). Blowdown plugs on underground sections of the gas pipeline shall be at least 3 m high from the ground surface. The plugs shall be welded with valves and connectors at a height of 1.5 m from the ground for gas sampling.

The exhaust of the gas-air mixture during the blowdown of gas pipelines should be carried out in places where it is excluded from entering the buildings and ignition from any source of fire.

Before filling the gas pipeline with gas, the air pressure in it must be reduced to atmospheric, then remove the plug installed after the disconnecting device at the point of connection of the gas pipeline. When supplying gas, the disconnecting devices must open slowly, smoothly. In this case, it is necessary to continuously monitor the gas pressure using a pressure gauge.

Gas pressure during blowdown of low-pressure gas pipelines shall be not higher than working pressure, medium-pressure and high-pressure gas pipelines - not higher than 0.1 MPa.

Air-gas mixture outlet speed is controlled by cranes on candles. Cranes should be opened sequentially according to the previously planned plan. In case of gas ignition on the spark plug, the valve shall be closed immediately.

Gas blowing must be performed before all air is displaced from the gas pipelines. The end of the purge is determined by analyzing or burning samples. Combustion of the gas-air mixture passed through the soap emulsion should occur calmly, without cotton.

During blowing at the candles there are locksmiths on duty. Samples taken must be taken from the candle at a distance of at least 10 m.

During the blowdown of the gas pipeline, the locksmith on duty does not allow unauthorized persons and transport to the blowdown site.

12. Removal of the plug in the well is carried out by workers in gas masks and rescue belts, using a sparking tool. On the surface of the earth on the windward side there are at least two people holding the ends of the ropes from the rescue belts of the workers in the well and conducting continuous monitoring of the work. The pit is pre-checked for gas content and ventilated if necessary. The presence of unauthorized persons near the well and the use of open fire are not allowed.

13. Upon completion of gas blowing, plugs and pressure gauges installed on gas pipelines are removed. Steel plugs are screwed into the nozzles, which must then be welded, checked for density with a gas indicator or soap emulsion at operating pressure and isolated (on underground gas pipelines). The locations of brewed plugs are included in the drawings of the contractor's documentation.

14. Upon completion of all gas pipeline connection and start-up works, it is necessary to:

• check tightness of tie-in welds with instrument or soap emulsion under operating gas pressure;

• bypass the route of the connected gas pipeline;

• perform isolation of the tie-in point and check the quality of insulation after backfilling of the trench using the instrument method;

• make a mark in the order for gas hazardous works on performance of works (Appendix B).

The permit for gas hazardous works shall be attached to the execution documentation and stored with it.

15. All gas pipelines put into operation are taken into account in a special journal. Operation certificate (F 7E) shall be maintained for underground gas pipelines.

3.3 Tests [4]

1. Gas pipelines completed by construction should be tested for air tightness. For testing, the gas pipeline in accordance with the work design should be divided into separate sections limited by plugs.

Tests of gas pipelines shall be carried out by construction and installation equipment in the presence of a representative of the operational organization. Test results shall be recorded in the construction certificate.

2. Prior to the leak test, the inside of the gas pipeline shall be cleaned in accordance with the work design. Cleaning of internal gas pipelines cavity should be performed before their installation by air blowing.

3. For tests of gas pipelines, pressure gauges of accuracy class 0.15 shall be used. It is allowed to use pressure gauges of accuracy class 0.40, as well as accuracy class 0.6. V-shaped liquid pressure gauges (water filled) shall be used at a test pressure of up to 0.01 MPa.

4. Tests of underground gas pipelines should be carried out after their installation in a trench and filling above the upper generatrix of the pipe by at least 0.2 m or after full filling of the trench.

5. Gas pipelines shall be held under test pressure for the time required to equalize the air temperature in the gas pipeline with the ground temperature prior to the start of the leak test.

6. Gas pipelines are tested for tightness by supplying compressed air to the gas pipeline and creating test pressure in the gas pipeline.

7. Test standards for steel underground gas pipelines shall be adopted as per Table

8. The results of the leak test should be considered positive if the pressure in the pipeline does not change during the test period, that is, there is no visible pressure drop.

When completing the gas pipeline tests, the pressure should be reduced to atmospheric pressure, automatics, valves, equipment, instrumentation should be installed and the gas pipeline should be kept under operating pressure for 10 minutes. Leak tightness of detachable joints should be checked with soap emulsion.

Defects found during tests of gas pipelines should be eliminated only after the pressure in the gas pipeline is reduced to atmospheric.

Once the defects found as a result of the gas pipeline leak test have been eliminated, this test shall be repeated.

Gas pipeline joints welded after testing shall be checked by physical inspection.

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