Order of the Federal Environmental, Industrial and Nuclear Supervision Service (Rostechnadzor) No. 531 of 15 December 2020
Unofficial translation. Only the Russian original published in the official sources of the Russian Federation has legal force. This translation is provided for reference and does not replace the official document.
1. The Federal Norms and Rules in the field of industrial safety "Safety Rules for Gas Distribution and Gas Consumption Networks" (hereinafter - the Rules) have been developed in accordance with Federal Law No. 116-FZ of 21 July 1997 "On Industrial Safety of Hazardous Production Facilities" (Collected Legislation of the Russian Federation, 1997, No. 30, Article 3588; 2018, No. 31, Article 4860) (hereinafter - the Federal Law "On Industrial Safety of Hazardous Production Facilities").
2. The Rules establish requirements aimed at ensuring industrial safety and preventing accidents and cases of work-related injuries at hazardous production facilities of gas distribution and gas consumption. The Rules apply to the hazardous production facilities of gas distribution and gas consumption networks (including the gas consumption networks of thermal power plants (hereinafter - TPP), gas turbine units (hereinafter - GTU) and combined-cycle units (hereinafter - CCU)). The Rules are intended for application during operation (including maintenance, technical diagnostics, current and capital repairs, technical re-equipment), reconstruction, mothballing and decommissioning. The Rules do not apply to equipment and gas pipelines with a pressure of up to 1.2 MPa intended to support the process and the functioning of the site facilities of trunk gas pipelines, to the equipment of filling station sites (automotive gas-filling compressor stations) intended for fuelling vehicles with natural gas, or to the process pipelines of explosion- and fire-hazardous and chemically hazardous production facilities and of the gas facilities of metallurgical and coke-chemical enterprises and production units.
3. The requirements of the Rules apply to all organisations, regardless of their organisational and legal forms, engaged in the operation, technical re-equipment, repair, mothballing and decommissioning of gas distribution and gas consumption networks.
4. Operation, including repair and technical re-equipment, mothballing and decommissioning of gas distribution and gas consumption networks shall be carried out in accordance with the requirements of the Federal Law "On Industrial Safety of Hazardous Production Facilities", the Technical Regulations on the Safety of Gas Distribution and Gas Consumption Networks approved by Government Resolution of the Russian Federation No. 870 of 29 October 2010 (Collected Legislation of the Russian Federation, 2010, No. 45, Article 5853; 2011, No. 26, Article 3819), and the Rules.
5. In an organisation operating gas distribution or gas consumption networks, persons responsible for the safe operation of the hazardous production facilities of the gas distribution and gas consumption networks as a whole and for each section (facility) individually are appointed from among the managers or engineering and technical personnel who have passed attestation in the field of industrial safety.
6. Organisations operating gas distribution and gas consumption networks shall, in addition to the requirements provided for by the Federal Law "On Industrial Safety of Hazardous Production Facilities": carry out a set of activities, including monitoring, maintenance, repair and emergency dispatch support of the gas distribution and gas consumption networks, to keep the gas distribution and gas consumption networks in a serviceable and safe condition; ensure technical diagnostics of the gas pipelines, buildings and structures and the technical and process devices of the gas distribution and gas consumption networks upon reaching the service life limits established by the design documentation; keep the design and as-built documentation throughout the entire service life of the hazardous production facility (until decommissioning). The procedure and conditions for its storage are determined by an order of the head of the operating organisation; where there is no gas service within the organisation operating the gas distribution and gas consumption networks, the enterprise may engage a contractor organisation to provide maintenance and repair services for the gas distribution network and the gas consumption network.
7. The requirements of this Chapter of the Rules apply to the gas pipelines (pipelines and connecting parts) and the technical and process devices of the gas distribution and gas consumption networks of TPPs with a natural gas pressure of up to and including 1.2 MPa.
8. Operation of the gas distribution and gas consumption networks of TPPs includes: process control; maintenance; technical diagnostics; repair; emergency recovery work; switching on and switching off of seasonally operated equipment.
9. Operation of the gas distribution and gas consumption networks of a TPP shall be carried out by the operational personnel and the gas service of the enterprise.
10. At a TPP, a person responsible for the safe operation of the gas distribution and gas consumption networks and a deputy of that person shall be appointed from among the managers (engineering and technical personnel) who have passed attestation in the field of industrial safety.
11. The person responsible for the safe operation of the gas distribution and gas consumption networks of a TPP shall have the following documentation: a copy of the administrative document of the operating organisation assigning responsibility for the safe operation of the gas distribution and gas consumption networks; a job description defining duties, rights and responsibility; design, working and as-built documentation; the acceptance certificate for the gas consumption networks; process diagrams of the external and internal gas pipelines indicating gas-hazardous wells and chambers; operational documentation on the safe use of gas; documents on the assessment (confirmation) of conformity of technical devices with the mandatory requirements established by the legislation of the Russian Federation; the plan of actions for localisation and elimination of consequences of accidents (hereinafter - the PMLA); copies of documents confirming attestation in the field of industrial safety of the workers operating the gas distribution and gas consumption networks, to the extent of the industrial safety requirements necessary for the performance of their job duties.
12. At a TPP, taking into account the specific features of the equipment, technology and nature of production, production (process) instructions shall be developed before the equipment is put into operation, containing the requirements for the process sequence of various operations when preparing the equipment of process complexes for start-up, placing into reserve, repair, and admitting repair personnel (workers) to work on the equipment. The production (process) instructions shall specify the methods and scope of checking the quality of the maintenance and repair work performed. The following shall be developed separately: instructions for the safe conduct of hot work and gas-hazardous work; labour protection instructions for workers engaged in operating the gas distribution and gas consumption networks, developed on the basis of the profession or type of work performed, taking into account the labour legislation of the Russian Federation; job descriptions for managers and engineering and technical personnel.
13. The production instructions shall be developed taking into account the requirements of the manufacturers of the technical devices and the specific operating conditions, and shall be approved by the technical manager of the TPP.
14. The production instruction shall be accompanied by process diagrams indicating the technical devices, the tie-in points of drains, purge gas pipelines (vents), relief gas pipelines and purge agent pipelines, and the location of shut-off, control and safety valves, with numbering corresponding to the actual on-site arrangement.
15. During operation of the gas distribution and gas consumption networks of a TPP, the following shall be ensured: supply of gas to the gas-using equipment at the required pressure, cleaned of foreign impurities and condensate, in a quantity corresponding to its load; safe operation of the equipment, as well as safe conduct of its maintenance and repair; timely maintenance and repair of the equipment; production control over compliance with industrial safety requirements.
16. A passport shall be drawn up for each gas pipeline (external and internal) and process device (gas reduction point (hereinafter - GRP), gas regulating unit (hereinafter - GRU), boiler), containing the basic data characterising the gas pipeline, the GRP room, the technical devices and the control and measuring instruments (hereinafter - instrumentation), as well as information on the technical diagnostics, maintenance and repairs performed.
17. Process diagrams of the gas pipelines shall be displayed in the rooms of the GRPs and control panels or reproduced on the computer screens of the automatic control systems.
18. During operation of gas pipelines and technical devices, the following shall be carried out: visual inspection of the technical condition (walk-round) within the time limits specified in the operational documentation; checking of the actuation parameters of the safety shut-off valve (hereinafter - SSV) and the safety relief valve (hereinafter - SRV) installed in the GRP (GRU) after each repair, but at least once every 6 months; checking of the actuation of the SSVs included in the protection and interlock schemes of boilers before each start-up of the boiler after an idle period of more than 3 days, after each repair, but at least once every six months; checking of the tightness of flanged, threaded and welded joints of gas pipelines and of the gland packings of valves using instruments or a foam-forming solution during maintenance, but at least once every 6 months; monitoring of gas contamination of the air in the GRP rooms and the boiler hall (boiler house) - continuously by automatic gas contamination alarms and at least once per shift using a portable gas analyser; checking of the operability of the automatic gas contamination alarms in the GRP rooms and the boiler hall (boiler house) at least once per shift using a portable gas analyser; checking of the actuation of process protection devices and interlocks and of the operation of alarms before each start-up of equipment and periodically in accordance with the approved schedule; cleaning of filters in accordance with the requirement of the manufacturing organisation, but at least once every 12 months; maintenance of gas pipelines and technical devices in accordance with the requirement of the manufacturing organisation, but at least once every 6 months; maintenance of the corrosion protection facilities of gas pipelines in accordance with the requirement of the manufacturing organisation, but at least once every 12 months; switching on and switching off of gas pipelines and technical devices into the reserve, repair and mothballing modes; technical diagnostics of gas pipelines and technical devices; repair; disconnection of idle gas pipelines and technical devices with the installation of blanking plugs.
19. During maintenance of gas pipelines, the condition of the seals of the protective sleeves at the points where the gas pipelines pass through the external building structures of the building is checked, as well as the presence of uniform gaps between the sleeves and the gas pipelines. The results of the check are recorded in the logs of maintenance of gas pipelines and gas-using equipment.
20. During operation of the buildings of the gas consumption network of a TPP, the operating organisation monitors the settlement of the foundations.
21. Visual inspection of the technical condition (walk-round) of the gas consumption network of a TPP is carried out within time limits that ensure the safety and reliability of its operation, but not less frequently than the time limits specified in the operational documentation. In the absence thereof, at least: once per shift for GRPs and the internal gas pipelines of the boiler house; once a month for above-ground gas pipelines. The frequency of walk-rounds of the routes of underground gas pipelines is established by the technical manager of the TPP on a differentiated basis depending on the technical condition of the gas pipelines and the duration and conditions of their operation (corrosion hazard, gas pressure, nature of the terrain and density of its development, season of the year, soil conditions). Gas pipelines shall be inspected after the identification of ground deformation, seismic impacts and other adverse phenomena that may cause impermissible stresses in the gas pipeline. During inspection of underground gas pipelines, wells located at a distance of up to fifteen metres on both sides of the gas pipeline, utility tunnels, basements of buildings and other premises where gas may accumulate are checked for gas contamination. During visual inspection, tightening of glands on valves and pumping of condensate out of the drainage devices of gas pipelines with a pressure of more than 0.3 MPa shall not be permitted. The tightness of the joints of the gas pipeline and of the valves installed on it is checked once a day by external signs of gas leakage (by smell, sound) using highly sensitive gas analysers (leak detectors) or a foam-forming solution (soap emulsion). The use of open flame to detect gas leaks shall not be permitted.
22. The actuation parameters of the SSVs and SRVs in GRPs shall be checked at least once every six months, and also after repair of the GRP equipment.
23. The actuation of the SSVs of boilers and burners shall be checked before light-up of the boiler on gas after an idle period of more than three days, before a planned changeover of the boiler to gas firing, and also after repair of the boiler gas pipelines. Interruption of the electricity supply from an external source shall cause the burner SSVs to close without any additional supply of energy from other external sources.
24. The setting and operation of the safety devices of gas-using equipment are checked before gas start-up, after a prolonged (more than two months) shutdown of the equipment, and also during operation within the time limits established in the operational documentation, but at least once every two months.
25. The actuation of process protection devices and the operation of alarms for maximum and minimum gas pressure in the gas pipelines are checked within the time limits established by the manufacturers, but at least once every six months. Excess gas pressure shall be relieved outside the premises, and the relief shall be safe for personnel and preclude ignition of the gas from a source of fire. Gas relief systems shall ensure safe conditions for gas dispersion, taking into account local climatic conditions, including the wind rose. The working gas pressure in the gas pipelines shall not change during the check. Interlocks are checked before start-up of the boiler or its changeover to gaseous fuel.
26. Monitoring of gas contamination in the GRP rooms and the boiler house shall be carried out by stationary gas contamination alarms or by a portable instrument from the upper zone of the premises at least once per shift. If a gas concentration is detected, additional ventilation shall be arranged and immediate work shall be organised to locate and eliminate the gas leak. Before entry into the premises, the premises shall be checked for gas contamination with a portable alarm.
27. Gas pipelines shall be drained regularly (according to a schedule) through fittings installed at the low points of the gas pipeline. Condensate is collected in mobile containers and disposed of. Discharge of the liquid removed from the gas pipeline into the sewerage system shall not be permitted.
28. The GRP filter shall be cleaned when the permissible pressure differential value specified in the passport of the technical device is reached.
29. Before the start of and during maintenance work, the air of the working zones of the premises (GRP, machine hall, boiler house) shall be monitored for gas contamination, with the analysis results noted in the permit to work for gas-hazardous work. If the gas concentration in the premises exceeds ten per cent of the lower concentration limit of flame propagation (hereinafter - LCLFP), the work shall be suspended. After completion of work involving a breach of integrity and depressurisation, the gas pipelines shall be tested for tightness, and after welding work - for strength and tightness in accordance with the design documentation. Where the design documentation contains no requirements for testing, the tests shall be carried out taking into account the current standardisation documents and acts in the field of technical regulation. The tests shall be carried out by the workers who performed the repair work, in the presence of the operational personnel of the TPP. The test results are documented in a certificate.
30. Maintenance of technical devices is carried out according to a schedule. For the component parts of the gas distribution network and the gas consumption network, maintenance is carried out together with the gas pipeline, unless otherwise established by the operational documentation of the manufacturing organisation.
31. Maintenance of gas pipelines shall be carried out at least once every six months.
32. During maintenance of a GRP, the following shall be carried out: checking of the travel and tightness of the shut-off devices (gate valves, cocks), as well as the tightness of the SSVs and SRVs, using an instrument or a foam-forming solution (soap emulsion); visual inspection of the building structures separating rooms of category A in terms of explosion and fire hazard (in accordance with the requirements of Federal Law No. 123-FZ of 22 July 2008 "Technical Regulations on Fire Safety Requirements" (Collected Legislation of the Russian Federation, 2008, No. 30, Article 3579, 2018, No. 53, Article 8464)) from other rooms; checking of the tightness at the points where the linkages of the mechanism actuators with the CV pass through; checking of the tightness of flanged and welded joints of gas pipelines using an instrument or a foam-forming solution; inspection and cleaning of the filter; checking of the linkages of the mechanism actuators with the control valve (hereinafter - CV), elimination of play and other faults in the kinematic transmission; purging of the impulse lines of measuring instruments, the SSV and the CV; checking of the setting parameters of the SSV and SRV; lubrication of rubbing parts, tightening of valve glands, their cleaning; checking of the condition and operation of the electrical equipment and the ventilation, heating and alarm systems.
33. During maintenance of internal gas pipelines, the following shall be carried out: checking of the tightness of flanged and welded joints of gas pipelines and of the gland packings of valves using instruments or a foam-forming solution (soap emulsion); tightening of valve glands, cleaning; purging of the impulse lines of measuring instruments.
34. When gas-using equipment of seasonal operation is disconnected, blanking plugs shall be installed on the branch gas pipelines to it.
35. Maintenance of the gas distribution and gas consumption networks of a TPP shall be carried out by a work team of at least three persons under the supervision of a foreman, with a permit to work for gas-hazardous work issued, during daylight hours or with sufficient artificial lighting.
36. Current repair involving dismantling of pressure regulators, safety valves and filters is carried out within the time limits established in the operational documentation, but at least once every twelve months, unless otherwise established by the operational documentation of the manufacturing organisation.
37. Current repair of gas pipelines and technical devices shall be carried out on disconnected equipment and gas pipelines, with blanking plugs installed at the boundaries of the disconnected section on the gas supply side.
38. During current repair of above-ground gas pipelines, the following is carried out: elimination of sagging of the gas pipeline and bulging of supports, replacement and restoration of fastenings; dismantling and repair of shut-off valves that do not ensure tight closure, with lapping of the sealing surfaces; restoration of the anti-noise and thermal insulation coatings; cleaning and restoration of the paintwork of gas pipelines and shut-off valves (at least once every five years); checking of the tightness of joints and elimination of defects identified during maintenance.
39. During current repair of shut-off valves, the following shall be carried out: cleaning of the shut-off valves, repair of the actuator and its lubrication, packing of the gland; dismantling of shut-off valves that do not ensure tight closure of the gates, with lapping of the sealing surfaces; checking of the tightening (fastening) of flanged joints, replacement of worn and damaged bolts and gaskets; checking of the serviceability and repair of the drive device; where the shut-off valves are serviced by the manufacturer, the time limits and scope of work shall be determined by the operational documentation for the valves.
40. Before repair of gas-using equipment or inspection and repair of boiler furnaces or flue ducts, the gas-using equipment and ignition pipelines shall be disconnected from operating gas pipelines, with a blanking plug installed downstream of the shut-off valves.
41. After completion of repair on gas pipelines and technical devices, they shall be tested in accordance with the requirements of the design documentation; where the design documentation contains no requirements for testing, the tests shall be carried out in accordance with the requirements of the codes of practice for gas distribution and gas consumption networks.
42. Technical diagnostics (industrial safety expert review) of the gas pipelines and the technical and process devices of the gas distribution and gas consumption networks of TPPs shall be carried out to determine and forecast their technical condition (to determine the conformity of the object of the expert review with the industrial safety requirements applicable to it in accordance with the Federal Law "On Industrial Safety of Hazardous Production Facilities"). The service lives of the gas pipelines and the technical and process devices of the gas distribution and gas consumption networks of TPPs are established on the basis of calculations and are specified in the design documentation.
43. Repair of gas pipelines and technical devices is carried out according to schedules approved by the technical manager of the TPP and drawn up on the basis of the operational documentation of the manufacturers. Repair is also scheduled based on the results of maintenance and technical diagnostics. Repair of internal gas pipelines, gas-using equipment and boiler equipment shall be combined. Information on capital repairs shall be entered in the passport of the relevant gas pipeline and technical device. Where a technical device forms part of a gas pipeline and is entered in the "Gas Pipeline Equipment" section of the passport, information on the repair of that technical device may be entered in the gas pipeline passport only. Passports of the relevant gas pipeline and technical device may be kept in electronic form. Where passports are kept in electronic form, any possibility of altering and/or distorting previously made entries shall be excluded.
44. After repair work has been completed, adjustment work shall be carried out.
45. Emergency disconnection of gas pipelines shall be carried out in cases of rupture of welded joints, corrosion or mechanical damage to the gas pipeline and valves with gas escape, and also in the event of an explosion or fire directly threatening the gas pipelines and gas-using equipment.
46. If gas contamination is detected, all work shall be suspended, and measures shall be taken to eliminate the gas leak and to carry out the actions in accordance with the PMLA and the production instructions. Persons not involved in the emergency recovery work shall be removed from the danger zone.
47. Gas-hazardous work shall be performed in accordance with the requirements of Chapter V of the Rules. The permit to work for gas-hazardous work for TPPs (Appendix No. 1 to the Rules) is drawn up in accordance with the mandatory requirements established by the legislation of the Russian Federation on technical regulation.
48. Before the start of work involving dismantling of shut-off valves, connection or repair of internal gas pipelines or work inside boilers, and also when boilers are placed into mothballing and repair mode, the shut-off devices installed on the branches of the gas pipeline to the boiler and on the gas pipeline to the protective ignition device (hereinafter - PID) of the burners shall be closed, with blanking plugs installed. The gas pipelines shall be freed of gas by purging with air or inert gas.
49. Blanking plugs on internal gas pipelines shall be installed on a disconnected section after the section has been purged with air or inert gas and a sample has been taken for analysis of the combustible gas content. Blanking plugs on a gas pipeline shall be removed after testing (control pressure test). Underground and above-ground (external) gas pipelines, regardless of the design pressure, shall undergo a control pressure test at a pressure of 0.02 MPa. The rate of pressure drop shall not exceed 100 Pa/hour. The equipment and gas pipelines of GRPs shall undergo a control pressure test at a pressure of 0.01 MPa. The rate of pressure drop shall not exceed 600 Pa/hour. If the pressure drop exceeds the permissible norms, gas start-up and removal of blanking plugs on the gas pipelines shall not be permitted until the causes of the excessive pressure drop have been eliminated and a repeat control pressure test has been carried out. The results of the control pressure test shall be recorded in the permit to work for gas-hazardous work. If the sections of gas pipelines that have been inspected and subjected to the control pressure test have not been filled with gas, the inspection and pressure test of the section being put into service shall be repeated when gas start-up work is resumed.
50. When gas is started up after mothballing or repair, blanking plugs on the gas pipelines of GRPs shall be removed after inspection of the technical condition (walk-round) of the gas pipelines, maintenance and testing, and after repair on the gas pipeline (welding work) - after a strength and tightness test in accordance with the requirements of the Rules.
51. Before the start of and during work to install and remove blanking plugs, the working zone shall be checked for gas contamination using gas analysers. If the maximum permissible concentration of gas in the air of the working zone exceeds three hundred milligrams per cubic metre, the work shall be performed in hose breathing apparatus or oxygen-isolating breathing apparatus. If the gas concentration in the working zone exceeds ten per cent of the LCLFP, the work shall be suspended and the premises shall be ventilated.
52. Blanking plugs on the gas pipelines of a boiler when it is taken out of mothballing or repair mode shall be removed after inspection of the technical condition of the boiler, maintenance and testing, checking of the operability of the process protections, interlocks and alarms, and also after an entry by the responsible person in the operational log on the readiness of the boiler for light-up.
53. Process protections, interlocks and alarms placed into permanent operation shall be switched on throughout the entire operating time of the gas-using equipment.
54. Repair and adjustment work in the circuits of protections, interlocks and alarms on operating equipment without a permit to work (instruction) for gas-hazardous work shall not be permitted.
55. The shut-off valves on the gas pipeline upstream of the burner device shall be opened after completion of ventilation of the gas-air path and activation of the PID.
56. Before start-up of a boiler after repair, the serviceability and readiness for activation of the main and auxiliary equipment, instrumentation, remote and automatic control facilities, process protection devices, interlocks, information facilities and operational communications shall be checked. Any faults identified in the process shall be eliminated before start-up. Before start-up of a boiler after it has been in reserve for more than three days, the following shall be checked: operability of the equipment, control and measuring instruments, remote and automatic control facilities, process protection devices, interlocks, information and communication facilities; passage of the commands of the process protections to all actuating devices; serviceability and readiness for activation of those devices and equipment on which repair work was performed during the idle period. Any faults identified shall be eliminated before ignition of the boiler. If faults are detected in the protection and interlock facilities acting on the blocking devices of the boiler, ignition of the boiler shall not be permitted.
57. Gas shall be started up into the boiler gas pipeline with the smoke exhausters, forced-draught fans and recirculation smoke exhausters in operation, in the sequence specified in the production instruction for operation of the boiler.
58. Purging of the boiler gas pipelines through the safety pipelines or through the gas burner devices of the boiler shall not be permitted.
59. Before light-up of a boiler from the cold state, a pre-start check of the tightness of closure of the shut-off valves upstream of the boiler burners, including the common boiler SSV, shall be carried out with the draught machinery in operation, as well as an automatic check of the tightness of closure of the SSVs installed upstream of each burner of the boiler. If leaking gates of the shut-off devices are detected, light-up of the boiler shall not be permitted.
60. Immediately before light-up of the boiler and after its shutdown, the furnace, the flue ducts removing the combustion products of the boiler, the recirculation systems and the enclosed volumes housing the headers shall be ventilated with all smoke exhausters, forced-draught fans and recirculation smoke exhausters switched on for at least ten minutes, with the dampers (valves) of the gas-air path open and an air flow rate of at least twenty-five per cent of the nominal value.
61. Ventilation of boilers operating with pressurised furnaces, as well as of hot-water boilers where there is no smoke exhauster, shall be carried out with the forced-draught fans and recirculation smoke exhausters switched on.
62. Before light-up of the boiler, if the gas pipelines have not been under excess pressure, the oxygen content in the boiler gas pipelines shall be determined. If the oxygen content is more than one per cent by volume, ignition of the burners shall not be permitted.
63. Light-up of boilers in which all burners are equipped with ignition protection devices and two safety shut-off valves begins with the ignition of any burner in the sequence specified in the boiler operating instructions. If the first burner being lit fails to ignite (is extinguished), the gas supply to the boiler and the burner shall be stopped, its ignition protection device shall be switched off, and the burner, the furnace and the flue ducts shall be ventilated in accordance with the requirements of the Rules, after which light-up of the boiler is resumed on another burner. Re-ignition of the first burner being lit shall be carried out after the causes of its failure to ignite (extinction) have been eliminated. In the event of failure to ignite (extinction) of the flame of the second or subsequent burners being lit (with stable combustion of the first), the gas supply to that burner only shall be stopped, its ignition protection device shall be switched off, and the burner shall be ventilated with the shut-off device on the air duct to that burner fully open. Its re-ignition is carried out after the causes of its failure to ignite (extinction) have been eliminated.
64. If all the burners in operation are extinguished during light-up, the gas supply to the boiler shall be immediately stopped, their ignition protection devices shall be switched off, and the burners, the furnace and the flue ducts shall be ventilated in accordance with the requirements of the Rules. Repeated light-up of the boiler shall be carried out after the causes of the extinction of the burner flames have been ascertained and eliminated.
65. The gas supply to the boiler gas pipelines shall be immediately stopped by the operating personnel in the following cases: failure of the process protections to operate; an explosion in the furnace or flue ducts, heating (visually) of the load-bearing frame beams or columns of the boiler, or collapse of the furnace brickwork; loss of voltage on the remote and automatic control devices or on all instrumentation; an uncontrolled change of the gas pressure to values outside the limits established by the design documentation; rupture of a boiler gas pipeline.
66. In the event of an emergency shutdown of the boiler, the gas supply to the boiler, all boiler burners and their ignition protection devices shall be stopped, and the disconnecting devices on the safety pipelines shall be opened. The disconnecting devices on the purge gas pipelines shall be opened and the furnace and flue ducts shall be ventilated in accordance with the requirements of the Rules.
67. In the event of a planned shutdown of the boiler for transfer to standby mode, the gas supply to the boiler, the burners and the ignition protection devices shall be stopped with their subsequent disconnection; the disconnecting devices on the safety pipelines and on the purge gas pipelines shall be opened, and the furnace and flue ducts shall be ventilated. Upon completion of ventilation, the draught machines shall be switched off, and the manholes, hatches, dampers (valves) of the gas-air path and the guide vanes of the draught machines shall be closed.
68. If the boiler is in reserve or operates on another type of fuel, the blanking plugs downstream of the shut-off valves on the boiler gas pipelines may be left uninstalled. Excess gas pressure may be present in the boiler gas pipelines during operation on another fuel, provided that tight closure of the disconnecting devices upstream of the boiler burners is ensured.
69. The procedure for transferring a boiler from pulverised coal or liquid fuel to natural gas shall be determined by the production instructions for boiler operation. Where the burners are arranged in several tiers, the burners of the lower tiers shall be transferred to gas first. Before a planned transfer of the boiler to natural gas, testing of the actuation of the safety shut-off valves and of the operability of the process protections, interlocks and alarms of the gas consumption network shall be carried out, with action upon the actuators or upon a signal, to an extent not preventing operation of the boiler.
70. Monitoring of the technical devices of the gas reduction point, the readings of the measuring instruments and the automatic gas contamination alarms shall be carried out by means of instruments from the control panels specified in the design documentation: the central control panel of the thermal power plant; the control panel of the boiler-turbine shop; from the local control panel of the gas reduction point; visually on site, during rounds.
71. The shut-off valves upstream of the safety relief valves in the gas reduction point shall be in the open position and shall be sealed.
72. The standby reduction line in the gas reduction point shall be in constant readiness for operation.
73. Process equipment and monitoring, control, alarm and communication devices shall be subjected to external inspection at the following intervals: process equipment, pipeline valves, electrical equipment, protective equipment and process pipelines - before the start of the shift and during the shift at least once every two hours; monitoring and control devices, actuators, alarm and communication devices - at least once a day; ventilation systems - before the start of the shift; fire safety and fire-extinguishing equipment - at least once a month. The results of the inspections shall be entered in the shift handover log (operations log) at the end of the shift. This log may be kept in electronic form. Where the log is kept in electronic form, the possibility of altering and/or distorting previously made entries shall be excluded.
74. It shall be prohibited to take process protections ensuring explosion safety out of service on operating equipment. The process protections ensuring explosion safety include protections against: a change of the gas pressure to values outside the limits established by the design documentation; failure of the flame of the first burner being lit to ignite; extinction of the flames of all burners in the furnace (of the common flame in the furnace); shutdown of all induced-draught fans (for boilers with balanced draught); shutdown of all forced-draught fans; shutdown of all regenerative air heaters. Other process protections, as well as process interlocks and alarms, may be taken out of service on operating equipment only in the daytime and no more than one protection, interlock or alarm at a time, in the following cases: an identified fault or failure; periodic testing in accordance with the schedule approved by the technical manager of the thermal power plant; operation of the equipment in transient modes, where the need to switch off the protection is determined by the operating instructions for the main equipment. Switching off shall be carried out on the written instruction of the shift supervisor of the shop or the shift supervisor of the power plant within the limits of their official powers, with an entry in the operations log and mandatory notification of the technical manager of the thermal power plant. Repair and adjustment work in the circuits of switched-on protections shall be prohibited. Process protections placed in permanent service shall be switched on throughout the entire time of operation of the equipment on which they are installed.
75. Repair and adjustment work in the circuits of protections, interlocks and alarms on in-service equipment without issue of a permit to work shall be prohibited.
76. Work on the adjustment and repair of automation systems, emergency protections and alarms under gas contamination conditions shall be prohibited.
77. Faults in regulators causing an increase or decrease of the working pressure, malfunctions in the operation of safety valves, and gas leaks shall be eliminated immediately upon their detection in accordance with the plan of actions for the localisation and elimination of the consequences of accidents and the production instructions.
78. Operation testing of protection devices, interlocks and alarms shall be carried out within the time limits provided for by the operating documentation of the manufacturers of that equipment, but at least once every 6 months.
79. When being filled with gas, gas pipelines shall be purged until all air has been displaced. Completion of purging shall be determined by analysis of the samples taken, whereby the oxygen content shall not exceed one per cent by volume, or by safe combustion of the gas samples taken, which shall proceed calmly, without pops. During purging of gas pipelines, the gas-air mixture shall be discharged to places where the possibility of its entering buildings, as well as of its ignition from any source of fire, is excluded. When being emptied of gas, gas pipelines shall be purged with air or inert gas until the gas has been completely displaced. Completion of purging is determined by analysis. The residual volume fraction of gas in the purge air shall not exceed twenty per cent of the lower concentration limit of flame propagation.
80. The requirements of this Chapter apply to gas turbine units of thermal power plants and power-generating gas turbine units operating autonomously or as part of combined-cycle units with a natural gas pressure exceeding 1.2 MPa.
81. The gas distribution and gas consumption networks of thermal power plants with gas turbine units and combined-cycle units shall ensure uninterrupted, safe transport and use of natural gas with the pressure and flow parameters determined by the design documentation and the operating conditions.
82. Gas supply to the thermal power plant during operation of gas turbine units and combined-cycle units shall be provided via two gas pipelines. Where there is no standby fuel in the network of the gas turbine units and combined-cycle units, the gas supply to the thermal power plant shall be provided via two gas pipelines from one gas distribution station connected to two independent trunk gas pipelines, or from two trunk gas pipelines.
83. The gas consumption network of gas turbine units and combined-cycle units shall provide the GT with the design gas pressure upstream of the burner devices. The gas consumption network diagrams of gas turbine units and combined-cycle units are provided either as combined (with power boilers) or as separate, depending on the location of the thermal power plant and the gas pressure at the connection point.
84. Technical devices used in the gas consumption network of gas turbine units and combined-cycle units shall have documentation on the assessment (confirmation) of the conformity of the technical devices with the mandatory requirements established by the legislation of the Russian Federation on technical regulation.
85. The scope of equipping the burner devices and the combustion chamber of the gas turbine (hereinafter referred to as the GT) with monitoring devices shall be determined taking into account the operating documentation for the gas turbine unit and the Rules.
86. The apparatus in each gas cleaning stage are provided with a fifty per cent capacity reserve. On the gas pipeline to the gas cleaning unit, a disconnecting device with an electric drive controlled from the local control panel of the gas preparation point (hereinafter referred to as the GPP) shall be provided.
87. Gas pipelines from the filters installed on the gas pipeline to the gas burner devices of the GT shall be made of corrosion-resistant steel.
88. Steels for gas pipelines and shut-off valves shall be selected depending on the operating parameters of the transported gas and the design outdoor air temperature in the construction area, which shall be taken as the temperature of the coldest five-day period of the year with a probability of 0.92.
89. At thermal power plants with gas turbine units and combined-cycle units, noise protection (silencers, anti-noise insulation) shall be provided to ensure the level of noise impact on the environment.
90. For the gas consumption network of thermal power plants with gas turbine units and combined-cycle units, in addition to the work specified in Section III of the Rules, operability testing of the safety shut-off valves included in the protection and interlock schemes of the gas turbine units and combined-cycle units shall additionally be performed in accordance with the schedules approved by the technical manager of the thermal power plant.
91. During operation of the GPP, the following shall be performed: visual monitoring of the technical condition (round) within the time limits established by the production instructions and ensuring the safety and reliability of operation; testing of the actuation parameters of the safety shut-off valves and safety relief valves - at least once every three months, as well as after completion of equipment repair; maintenance - at least once every 6 months; routine repair - at least once every 12 months, unless other repair intervals are established by the manufacturers of the gas equipment; capital repair - upon replacement of equipment or measuring instruments, or repair of the building or of the heating, ventilation and lighting systems, on the basis of defect lists drawn up according to the results of inspections and routine repairs.
92. Gas contamination monitoring in the GPP premises shall be carried out by stationary gas contamination alarms or by a portable instrument from the upper zone of the premises at least once a day. If a gas concentration of ten per cent or more of the lower concentration limit of flame propagation is detected, additional ventilation of the premises shall be arranged, the cause shall be identified and the gas leak shall be eliminated immediately.
93. Maintenance of the gas pipelines and technical devices of the GPP shall be carried out at least once every six months.
94. Operating booster compressors shall be under constant supervision by personnel. Operation of compressors with switched-off or failed automation, emergency ventilation, interlocks or exhaust system fans shall be prohibited.
95. Maintenance and routine repair of booster compressors and of safety shut-off and control valves are carried out in accordance with the operating documentation of the manufacturers of that equipment. Upon expiry of the warranty period, they shall undergo verification and servicing.
96. Booster compressors shall be subject to emergency shutdown in the following cases: emergency gas leaks; faults in the disconnecting devices; vibration, extraneous noises or knocking; failure of bearings or seals; a change of the permissible oil and water parameters; failure of the electric drive of the starting apparatus; faults in mechanical transmissions and drives; an increase or decrease of the specified gas pressure in the inlet and outlet branch pipes.
97. Compressor lubricating oil shall have a certificate and shall conform to the grade specified in the manufacturers' operating documentation for the compressor (in terms of viscosity, flash and auto-ignition temperatures, and thermal stability) and to the specific features characteristic of the operation of a compressor of the given type under the specific conditions.
98. Ventilation of the gas-air path of the waste heat boiler (hereinafter referred to as the WHB) forming part of gas turbine units and combined-cycle units shall be carried out by draught mechanisms.
99. To ventilate the gas-air path of gas turbine units and combined-cycle units after shutdown of the GT, the cold cranking mode of the GT, carried out by means of the starting devices, shall be used.
100. In the production zone of the GPP, the process equipment, gas pipelines, valves, electrical equipment, ventilation systems, measuring instruments, emergency protections, interlocks and alarms shall be inspected every shift; identified faults shall be eliminated in the manner and within the time limits established by the production (process) instructions. Putting process equipment into operation without a prior external inspection (round) shall not be permitted.
101. On the internal gas pipelines of gas turbine units and combined-cycle units, maintenance shall be carried out at least once a month and routine repair at least once every twelve months.
102. The frequency of repairs is established in accordance with the schedules approved by the technical manager of the thermal power plant, taking into account the actual condition of the equipment and according to the results of maintenance and routine repair.
103. The settings of the regulators in the GPP shall correspond to the working gas pressure values specified in the manufacturers' operating documentation for the supply of the gas turbine unit. Gas pressure fluctuations at the outlet may be within ten per cent of the working pressure.
104. The mode of setting and testing the actuation parameters of the safety valves shall not lead to a change of the working gas pressure downstream of the regulator.
105. Gas pipelines supplying gas to the units shall be purged when gas is started up. Purging shall be carried out through the purge gas pipelines to the places provided for by the design.
106. Start-up of the GT is carried out: from the cold state, at a turbine casing metal temperature below one hundred and fifty degrees Celsius, after installation or repair; from the non-cooled state, at a turbine casing metal temperature of one hundred and fifty to two hundred and fifty degrees Celsius; from the hot state, at a turbine casing metal temperature above two hundred and fifty degrees Celsius. The rates of increase of the gas temperature in the flow path, of the rotation speed and of load pick-up during start-up from each thermal state shall not exceed the values specified by the manufacturers.
107. Start-up of gas turbine units and combined-cycle units shall be carried out with the dampers to the flue stack fully open. Switching of the dampers and ignition of the WHB burners may take place only after the GT has reached idle speed.
108. The combustion chambers and gas-air paths of the gas turbine unit or combined-cycle unit, including the flue ducts and the WHB, shall be ventilated (aired) before ignition of the GT burner devices, using the GT starting device, ensuring six air changes of the ventilated volumes up to the flue stack. After each unsuccessful attempt to start the GT, ignition of fuel without prior ventilation of the gas-air paths of the gas turbine unit or combined-cycle unit shall be prohibited. The duration of ventilation shall correspond to the design documentation and shall be specified in the operating instructions and the start-up (ignition) programme. The shut-off valves on the gas pipeline upstream of the burner device shall be opened after completion of ventilation of the gas-air path and switching on of the ignition protection device.
109. If, during ignition of the flame tubes (gas burners) of the GT combustion chamber or in the course of regulation, flame lift-off, flashback or extinction has occurred, the supply of gas to the gas burner and its ignition device shall be immediately stopped. Re-ignition may be commenced after ventilation of the combustion chambers and gas-air paths of the gas turbine unit or combined-cycle unit for the time specified in the production instructions, and after the causes of the malfunctions have been eliminated.
110. The stop and control fuel valves of the GT shall ensure tightness. The valves shall be exercised through their full travel before each start-up, and also daily through part of their travel when the GT operates in base-load mode.
111. Leak-tightness testing of the closure of the stop valve and of the safety shut-off valves of the GT shall be carried out after repair with visual monitoring, before each start-up of the gas turbine unit, and also periodically at least once a month.
112. Start-up of the gas turbine unit shall be directed by the shift supervisor, and after repair or scheduled work - by the head of the shop or his deputy.
113. Before start-up of the gas turbine unit after repair or after standing in reserve for more than three days, the serviceability and readiness for switching on of the process protection and automation devices, the interlocks of auxiliary equipment, the oil system, the standby and emergency oil pumps, the instrumentation and the operational communication devices shall be checked. Any faults identified in the process shall be eliminated.
114. Start-up of the gas turbine unit shall not be permitted in the following cases: a fault in or disconnection of at least one of the emergency protection systems; the presence of defects in the control system which may lead to the permissible gas temperature being exceeded or to overspeeding of the turbine; a fault in one of the oil pumps or in the system for their automatic switching on; deviation from the oil quality standards, or an oil temperature below the established limit; deviation from the fuel quality standards, or a fuel temperature or pressure below or above the established limits; a gas leak; deviation of the monitored indicators of the thermal or mechanical condition of the gas turbine unit from the permissible values.
115. Start-up of the gas turbine unit after an emergency shutdown or after a failure during the previous start-up, if the causes of those failures have not been eliminated, shall not be permitted.
116. Start-up of the gas turbine unit shall be immediately terminated by the action of the protections or by personnel in the following cases: violation of the established sequence of start-up operations; a rise of the gas temperature above that permitted by the start-up schedule; an increase of the load of the starting device above the permissible level; a reduction, not provided for by the instructions, of the rotation speed of the shaft being run up after disconnection of the starting device; surge phenomena in the compressors of the gas turbine unit.
117. The gas turbine unit shall be immediately shut down by the action of the protections or by personnel in the following cases: an impermissible rise of the gas temperature upstream of the GT; an increase of the rotor rotation speed above the permissible limit; detection of cracks in, or rupture of, oil or gas pipelines; impermissible axial displacement or impermissible relative displacements of the rotors of compressors and turbines; an impermissible drop of the oil pressure in the lubrication system or of the level in the oil tank, as well as an impermissible rise of the oil temperature at the drain from any bearing or of the temperature of any of the thrust bearing pads; metallic sounds (grinding, knocking) or unusual noises being heard inside the turbomachines and GT apparatus; an increase of the vibration of the support bearings above the permissible values; the appearance of sparks or smoke from the bearings or end seals of the turbomachines or the generator; ignition of oil or fuel where it is impossible to extinguish the fire immediately with the means available; an explosion (pop) in the GT combustion chambers, in the WHB or in the flue ducts; flame extinction in the combustion chambers; an impermissible drop of the liquid or gaseous fuel pressure upstream of the GT stop valve; the closed position of the damper on the WHB flue stack or a rise of the gas pressure at the WHB inlet; loss of voltage on the control and automation devices or on all instrumentation; shutdown of the turbogenerator due to internal damage; the occurrence of compressor surge or an impermissible approach to the surge limit; an impermissible change of the air pressure downstream of the compressors; ignition of deposits on the heating surfaces of the WHB. Simultaneously with the shutdown of the GT by the action of the protection or by personnel, the generator shall be disconnected.
118. The gas turbine unit shall be unloaded and shut down by decision of the technical manager of the thermal power plant in the following cases: disruption of the normal operating mode of the GT or of the normal operation of auxiliary equipment, or the appearance of warning alarm signals, if the causes of the disruption cannot be eliminated without shutdown; sticking of the stop, control and anti-surge valves; icing of the air intake device, if the icing cannot be eliminated while the gas turbine unit operates under load; an impermissible rise of the temperature of the outer surfaces of the turbine casings, combustion chambers or transition pipelines, if that temperature cannot be reduced by changing the operating mode of the gas turbine unit; an impermissible increase of the non-uniformity of the measured gas temperatures; an impermissible rise of the air temperature upstream of the high-pressure compressors, as well as in cases of disruption of the normal water supply; faults in the protections affecting the assurance of explosion safety; faults in the operational instrumentation.
119. In the event of an emergency shutdown of the gas turbine unit or of a combined-cycle unit with a WHB, the following shall be done: the fuel supply to the GT combustion chamber shall be stopped by closing the stop valve, the safety shut-off valves and the other shut-off devices on the gas pipelines of the GT and the WHB; the purge gas pipelines and the safety pipelines on the disconnected gas pipelines of the GT and the WHB shall be opened; the steam turbine and the generator provided as part of the combined-cycle unit shall be disconnected.
120. It shall be prohibited to commence opening up the turbines, the combustion chamber, or the stop and control valves without making certain that the shut-off devices on the gas supply to the GT are closed, blanking plugs are installed on the gas pipelines, the gas pipelines have been emptied of gas, and the valves on the purge gas pipelines are open.
121. After shutdown of the gas turbine unit and combined-cycle unit, effective ventilation of the paths and other places provided for by the design documentation shall be ensured, and the burners shall be purged with air or inert gas. Upon completion of ventilation, the intake and (or) exhaust paths shall be shut off. The duration and frequency of ventilation and of rotor cranking during cooling down of the gas turbine unit shall be specified in the operating instructions.
122. The shut-off valves on the purge gas pipelines and safety gas pipelines shall remain permanently in the open position after shutdown of the gas turbine unit.
123. After completion of repair on gas pipelines and technical devices, they shall be tested for strength and leak-tightness in accordance with the requirements of the design and operating documentation.
124. Before repair of technical devices on a gas pipeline, or before visual monitoring and repair of combustion chambers or flue ducts, the technical devices and ignition pipelines shall be disconnected from the in-service gas pipelines with the installation of a blanking plug downstream of the shut-off valves.
125. Process protections, interlocks and alarms placed in permanent service shall be switched on throughout the entire time of operation of the equipment on which they are installed. Process protections shall be put into operation automatically.
126. It shall be prohibited to take process protections ensuring explosion safety out of service on operating equipment. Other process protections, as well as process interlocks and alarms, may be taken out of service on operating equipment only during daylight hours and no more than one protection, interlock or alarm at a time, in the following cases: detection of a fault or failure; periodic testing in accordance with the schedule approved by the technical manager of the thermal power plant. Switching off shall be carried out on the written instruction of the shift supervisor in the operations log, with mandatory notification of the technical manager of the thermal power plant.
127. Repair and adjustment work on protections, interlocks and alarms on in-service equipment without issue of a permit to work shall be prohibited.
128. Work on the adjustment and repair of automation systems, emergency protections and alarms under gas contamination conditions shall be prohibited.
129. Gas-hazardous work includes: process connection (tie-in) of newly built external and internal gas pipelines to in-service ones, and disconnection (cutting off) of gas pipelines; start-up of gas into gas pipelines upon commissioning, upon removal from mothballing, after repair (reconstruction), and commissioning of gas reduction points and gas regulating units; maintenance and repair of in-service external and internal gas pipelines, gas-using equipment, gas reduction points and gas regulating units; removal of blockages, installation and removal of blanking plugs on in-service gas pipelines, as well as disconnection of gas-using equipment from, or its connection to, gas pipelines and its adjustment; purging of gas pipelines when gas-using equipment is taken out of or put into operation; technical inspection (inspection of the technical condition) of gas pipelines, gas reduction points and gas regulating units, repair, inspection and airing of wells, and checking and pumping out of condensate from condensate collectors; checking the condition of the protection zones of gas pipelines; excavation at places of gas leaks until they are eliminated; liquidation and mothballing of gas pipelines, gas reduction points, gas regulating units and gas-using equipment (dismantling of gas equipment) upon their permanent or temporary withdrawal from operation; work using all types of welding and gas cutting on in-service gas pipelines and on process and technical devices of gas distribution or gas consumption networks; reduction and restoration of the gas pressure in a gas pipeline; performance of work on in-service gas pipelines in pits, trenches and excavations, or on technical devices in gas wells; monitoring of the technical condition of gas pipelines (with the exception of checking the condition of protection zones); monitoring of the intensity of the gas odour at the end points of gas distribution networks; monitoring of the gas pressure in the gas distribution network.
130. Gas-hazardous work shall be performed by a work team of at least two workers under the direction of an engineering and technical worker (comprising at least three workers). Gas-hazardous work not requiring the issue of a permit to work for its performance may be performed by two workers, one of whom is appointed as the person in charge of the work. Gas-hazardous work in wells, tunnels and collectors, as well as in trenches and excavations more than one metre deep, shall be performed by a work team of at least three workers under the direction of an engineering and technical worker (comprising at least four workers).
131. Repair work without the use of welding and gas cutting on low-pressure gas pipelines with a diameter of not more than fifty millimetres, inspection of the technical condition of external gas pipelines, repair, inspection and airing of wells (without descending into them), checking and pumping out of condensate from condensate collectors and water seals, as well as external inspection and cleaning of internal gas pipelines, technical devices and gas-using installations, and inspection of the technical condition of gas reduction points and gas regulating units, are carried out by two workers. Direction of the work is entrusted to the most qualified worker.
132. For the performance of gas-hazardous work in organisations operating gas distribution or gas consumption networks, a permit to work is issued, drawn up in accordance with the recommended form (Appendix No. 1 to the Rules), providing for the development and subsequent performance of a set of actions for the preparation and safe conduct of that work.
133. In an organisation operating gas distribution or gas consumption networks, a list of gas-hazardous work and an instruction determining the procedure for preparing such work and the safety of its performance in relation to the specific production conditions shall be developed and approved by the head of that organisation or his authorised deputy, or by the head of an independent structural subdivision (subsidiary company) of that organisation. A list of gas-hazardous work performed without issue of a permit to work in accordance with production instructions ensuring its safe performance is also approved. The list of gas-hazardous work shall be reviewed and re-approved at least once a year.
134. Workers having the right to issue permits to work for the performance of gas-hazardous work shall be appointed by an administrative document from among the managerial workers and engineering and technical workers operating gas distribution or gas consumption networks, certified in accordance with the established procedure and having not less than one year of work experience at facilities of gas distribution and gas consumption networks.
135. Periodically recurring gas-hazardous work performed by a permanent staff of workers is carried out under approved production instructions without issue of a permit to work. Periodically recurring gas-hazardous work performed without a permit to work includes: technical inspection of gas pipelines and gas reduction points (PRG); maintenance of PRG (cabinet type) carried out without reducing the gas pressure at consumers; checking the condition of gas pipeline protection zones; repair, inspection and ventilation of wells (without descending into them); checking and pumping out of condensate from condensate collectors; maintenance of gas pipelines without shutting off the gas; monitoring of the intensity of the gas odour; monitoring of the gas pressure in the gas distribution and gas consumption network; maintenance of shut-off valves and expansion joints located outside wells (without breaking the tightness of the body and flanged joints). Such work shall be performed by a crew of workers of at least two persons under the direction of an engineering and technical worker and shall be recorded in the log of periodically recurring gas-hazardous work, with the start and end times of the work indicated. The log may be kept in electronic form. Where the log is kept in electronic form, any possibility of altering and/or distorting previously made entries shall be excluded.
136. The following gas-hazardous work is carried out under a special plan approved by the technical manager of the gas distribution organisation: gas start-up into the gas distribution and gas consumption networks of settlements during initial gasification, into high-pressure gas pipelines; work on connecting high- and medium-pressure gas pipelines; repair work in PRG and gas control units (GRU) using welding and gas cutting; repair work on medium- and high-pressure gas pipelines (under gas) using welding and gas cutting; reduction and restoration of gas pressure in medium- and high-pressure gas pipelines involving disconnection of consumers; repair work on low-pressure gas pipelines involving shut-off and subsequent gas start-up into groups of residential buildings, if more than one crew is required to perform the work; shut-off and subsequent resumption of the gas supply to industrial production facilities. The plan states: the sequence of operations; the placement of people; the technical equipment; the actions ensuring safety; the persons responsible for carrying out the gas-hazardous work (separately for each work area) and for overall management and coordination of actions.
137. Each person responsible for carrying out gas-hazardous work is issued a separate permit to work in accordance with the plan.
138. As-built documentation (a drawing or photocopy of the as-built documentation) indicating the place and nature of the work being performed shall be attached to the plan and the permits to work. Before the start of gas-hazardous work, the person responsible for carrying it out checks that the documentation corresponds to the actual location of the gas pipeline.
139. Work on localising and eliminating accidents on gas pipelines is carried out without a permit to work until the direct threat of harm to the life, health or property of other persons and to the natural environment has been eliminated. Restoration work to bring gas pipelines and gas equipment into technically sound condition is carried out under a permit to work. Where emergency restoration work is carried out from start to finish by the emergency dispatch service within not more than one day, no permit to work is issued.
140. Permits to work for gas-hazardous work shall be issued in advance to allow the necessary preparation for the work. The permit to work states its period of validity and the start and end times of the work. If the work cannot be completed within the established time limit, the permit to work for gas-hazardous work shall be extended by the person who issued it. Entries in the permit to work for gas-hazardous work shall be clearly legible and shall raise no doubt or ambiguity as to the meaning of what is written, so as to prevent their imprecise execution. The permit to work for gas-hazardous work may be completed using a personal computer. Completion of the permit to work for gas-hazardous work in pencil shall not be permitted. Corrections in the text, signatures of responsible persons made using a facsimile, and photocopies thereof shall not be permitted. The possibility of using an electronic signature in the approval of permits to work for gas-hazardous work is established by the internal documents of the operating organisation in accordance with the requirements of Federal Law No. 63-FZ of 6 April 2011 "On Electronic Signatures" (Collection of Legislation of the Russian Federation, 2011, No. 15, Article 2036, 2020, No. 24, Article 3755). The permit to work for gas-hazardous work may be drawn up and registered in electronic form. In that case, any possibility of altering and/or distorting entries previously made in the permit to work shall be excluded, and conditions shall be ensured for keeping the permit to work for one year from the date of its closure.
141. Permits to work shall be registered in a special log (a recommended form is given in Appendix No. 2 to the Rules). The log may be kept in electronic form. Where the log is kept in electronic form, any possibility of altering and/or distorting previously made entries shall be excluded.
142. When receiving a permit to work, the person responsible for carrying out gas-hazardous work signs the permit-to-work registration log.
143. Permits to work shall be kept for at least one year from the date of their closure. The procedure and conditions for their keeping are determined by an order of the head of the operating organisation. Permits to work issued for initial gas start-up, tie-in to an operating gas pipeline, or shut-off of gas pipelines with permanent seal-welding at the branch points are kept permanently in the as-built technical documentation for the gas pipeline concerned.
144. If gas-hazardous work performed under a permit to work continues for more than one day, the person responsible for its performance shall report daily in writing on the progress of the gas-hazardous work to the person who issued the permit to work. If the work cannot be completed within the established time limit, the permit to work for gas-hazardous work shall be extended by the person who issued the permit to work.
145. Permits to work are issued to seconded workers, for a period not exceeding the duration of the secondment, by the persons referred to in paragraph 136 of the Rules. The performance of gas-hazardous work is monitored by a person appointed by the organisation performing the work, with mandatory periodic monitoring by an employee of the operating organisation. The frequency of monitoring by employees of the operating organisation shall be established by an administrative document of the organisation.
146. Before the start of gas-hazardous work, the person responsible for carrying it out shall instruct all workers on the process sequence of operations and the necessary safety measures and shall verify, by questioning, that the state of health of each worker does not prevent performance of the work. After that, each worker who has received the briefing shall sign the permit to work. Before gas-hazardous work begins in PRG premises, wells, tunnels and collectors, an analysis of the gas-air mixture is carried out using a gas analyser. Samples shall be taken at the most poorly ventilated points. Performance of gas-hazardous work in PRG premises, wells, tunnels and collectors shall not be permitted where the volume fraction of gas in the air exceeds 20 per cent of the lower concentration limit of flame propagation (LCLFP) and/or the oxygen content is less than 20 per cent.
147. During gas-hazardous work, all orders shall be given by the person (employee) responsible for the work. Other officials and managers present during the work give instructions only through the person responsible for carrying out the work.
148. Gas-hazardous work shall be performed in daytime (the day work shift). In areas of the northern climatic zone, gas-hazardous work is carried out regardless of the time of day. Work on localising and eliminating accidents is performed regardless of the time of day under the direct supervision of an engineering and technical worker.
149. Gas pipelines not put into operation within 6 months of the day of testing shall be retested for tightness. In addition, checks are made of the operation of the electrochemical protection installations, the condition of the flue and ventilation ducts (systems), and the completeness and sound condition of the gas equipment, valves, measuring instruments and automation equipment.
150. Newly constructed gas pipelines are connected to operating gas pipelines only before gas start-up. Before their connection to operating gas pipelines, and also after repair, all gas pipelines and gas equipment shall be subjected to external inspection and a control pressure test (with air or inert gases) by the crew performing the gas start-up.
151. External gas pipelines of all pressures shall be subjected to a control pressure test at a pressure of 0.02 MPa. The pressure drop shall not exceed 0.0001 MPa in one hour. External gas pipelines with a natural gas pressure of up to and including 0.005 MPa fitted with water seals shall be subjected to a control pressure test at a pressure of 0.004 MPa. The pressure drop shall not exceed 0.00005 MPa in ten minutes. Internal gas pipelines of industrial, agricultural and other production facilities and of boiler houses, as well as the equipment and gas pipelines of gas control points (GRP) (block-type gas control points (GRPB)), cabinet-type gas control points (ShRP) and GRU, shall be subjected to a control pressure test at a pressure of 0.01 MPa. The pressure drop shall not exceed 0.0006 MPa in one hour. The results of the control pressure test shall be recorded in the permits to work for the performance of gas-hazardous work.
152. Excess air pressure in the gas pipelines being connected shall be maintained until the start of the work on their connection (tie-in).
153. If gas start-up into the gas pipeline did not take place, then upon resumption of gas start-up work the gas pipeline shall undergo repeat inspection and a control pressure test.
154. During repair work in a gas-contaminated environment, non-ferrous metal tools that preclude spark formation shall be used. The working part of ferrous metal tools shall be liberally greased with solidol or another similar grease. The use of electric tools that produce sparking shall not be permitted. The footwear of persons performing gas-hazardous work in wells and in PRG and GRU premises shall have no steel heel plates or nails. When performing gas-hazardous work, portable explosion-proof lamps with a voltage of up to twelve volts shall be used.
155. Performance of welding work and gas cutting on gas pipelines in wells, tunnels, collectors, technical basements and PRG and GRU premises without shutting off the pipelines, purging them with air or inert gas and installing blinds shall not be permitted. Before the start of work on welding (cutting) a gas pipeline, or on replacing shut-off valves, expansion joints and insulating flanges, in wells, tunnels and collectors, the covers shall be removed (dismantled).
156. Gas cutting and welding on operating gas pipelines may be performed at a gas pressure of 0.0004 - 0.002 MPa. During performance of the work, the gas pressure in the gas pipeline shall be monitored continuously. If the gas pressure in the gas pipeline falls below 0.0004 MPa or rises above 0.002 MPa, the work shall be stopped.
157. Connection of gas pipelines without pressure reduction shall be performed using special equipment that ensures the safety of the work. The production instructions for work on connecting gas pipelines without pressure reduction shall take into account the recommendations of the equipment manufacturers and contain the process sequence of operations.
158. During the work, the gas pressure in the gas pipeline shall be monitored using a specially installed pressure gauge. A pressure gauge installed not more than one hundred metres from the place of work may be used.
159. Work on connecting gas-using equipment to operating internal gas pipelines using welding (cutting) shall be carried out with the gas pipelines shut off and purged with air or inert gas.
160. Gas pressure in an operating gas pipeline shall be reduced by means of shut-off devices or by adjustment of the pressure-reducing valves in the PRG. To prevent the gas pressure in the gas pipeline from being exceeded, excess pressure shall be discharged to the purge gas pipeline.
161. The methods of connecting newly constructed gas pipelines to operating ones are determined by the design documentation.
162. Checking the tightness of gas pipelines, valves and instruments with an open flame shall not be permitted. The presence of unauthorised persons, the use of open flame sources and smoking at the places where gas-hazardous work is performed shall not be permitted. The places of work shall be fenced off. Excavation pits shall be of dimensions convenient for performing the work and for the evacuation of workers. Warning signs "Flammable - Gas" are posted or put up near the places where gas-hazardous work is performed.
163. During gas cutting (welding) on operating gas pipelines, to avoid a large flame, the points where gas escapes are sealed with fireclay mixed with asbestos crumb.
164. Blinds installed on branches to consumers (service inlets) are removed on the instruction of the person directing the gas start-up work, after visual inspection and pressure testing of the gas pipeline.
165. During gas start-up, gas pipelines shall be purged with gas until all air has been displaced. Completion of purging shall be established by analysis and by burning the samples taken. The volume fraction of oxygen shall not exceed one per cent by volume, and combustion of the gas shall proceed steadily, without pops.
166. When being freed of gas, gas pipelines shall be purged with air or inert gas. After checking with a gas analyser, the volume fraction of gas in the sample of air (inert gas) shall not exceed twenty per cent of the LCLFP. When gas pipelines are being purged, release of the gas-air mixture into premises, into ventilation and flue systems, or into places where there is a possibility of it entering buildings or being ignited from a fire source shall be prohibited.
167. Sections of external gas pipelines being disconnected, and sections of internal gas pipelines when gas equipment is dismantled, shall be cut off, freed of gas and welded shut at the branch point.
168. In gas-contaminated wells, collectors and premises, and outdoors in a gas-contaminated atmosphere, repair work using an open flame (welding, cutting) shall not be permitted.
169. During maintenance and repair, gas-using equipment shall be disconnected from the gas pipeline by means of blinds.
170. Descent into wells (without step irons) and excavation pits shall be by metal ladders secured at the edge of the well (excavation pit). To prevent slipping and sparking when resting on a hard base, the ladders shall have rubber feet.
171. Before the start of gas-hazardous work, a laboratory or rapid analysis of the air shall be carried out for the content of oxygen and of the hazardous substances specified in the list of gas-hazardous work, according to the place and nature of the work, with the results recorded in the permit to work for gas-hazardous work and in the shift (operations) log. Work inside wells and collectors, in tunnels and in other similar devices and structures (containing a confined space) without isolating respiratory protective equipment shall not be permitted. Outside, on the windward side, two persons shall be present for each person working in wells and excavation pits, to provide backup and to prevent unauthorised persons from accessing the place of work.
172. Dismantling (replacement) of equipment installed on external and internal gas pipelines shall be performed on a shut-off section of the gas pipeline with blinds installed. Blinds shall correspond to the maximum gas pressure in the gas pipeline, have tails protruding beyond the flanges, and bear a stamp indicating the gas pressure and the diameter of the gas pipeline.
173. Tightening or replacing the gland packing of shut-off valves and dismantling the threaded joints of condensate collectors on medium- and high-pressure external gas pipelines may be performed at a gas pressure of not more than 0.1 MPa.
174. Replacement of gaskets of flanged joints on external gas pipelines may be performed at a gas pressure in the gas pipeline of 0.0004 - 0.002 MPa.
175. Dismantling of flanged and threaded joints and of valves on internal gas pipelines of any pressure shall be performed on a section of the gas pipeline that has been shut off and blinded.
176. During repair work on gas pipelines and equipment in premises where gas contamination is possible, supervision of the work and prevention of the introduction of fire sources and of spark formation shall be ensured.
177. Before the start of repair work on underground gas pipelines involving disconnection of the gas pipeline (replacement of gate valves, removal and installation of blinds or gaskets), the existing protection against electrochemical corrosion shall be switched off and a jumper shall be installed on the sections of the gas pipeline being disconnected (if there are no permanently installed jumpers) to prevent spark formation.
178. Clearing of ice, tar, naphthalene and other blockages in gas pipelines by rodding (with metal rods), by pouring in solvents or by steam supply may be performed at a gas pressure in the gas pipeline of not more than 0.005 MPa.
179. The use of an open flame to thaw external polyethylene gas pipelines, rehabilitated steel gas pipelines and internal gas pipelines shall be prohibited.
180. When clearing blockages in gas pipelines, measures shall be taken that minimise the escape of gas from the gas pipeline. The work shall be performed wearing hose breathing apparatus or oxygen-isolating breathing apparatus. Release of gas into premises shall be prohibited. When gas pipelines are being cleared, consumers shall be warned of the need to shut off gas-using equipment until the work is completed.
181. Threaded and flanged joints that were dismantled to clear blockages in the gas pipeline shall, after reassembly, be checked for tightness with soap emulsion or using highly sensitive gas analysers (leak detectors).
182. The person responsible for carrying out the work is responsible for workers having personal protective equipment, for its sound condition and for its use. The availability and sound condition of the necessary personal protective equipment are determined when the permit to work for gas-hazardous work is issued. When organising the work, the person responsible for carrying out the work shall provide for the possibility of quickly withdrawing workers from the danger zone. Each person taking part in gas-hazardous work shall have and, where necessary, use a hose breathing apparatus or oxygen-isolating breathing apparatus prepared for operation (for work performed in excavation pits, tunnels, wells, collectors and similar devices and structures (with confined spaces). The use of filtering breathing apparatus shall not be permitted.
183. Permission to switch on oxygen-isolating breathing apparatus is given by the person in charge of the work. When working in oxygen-isolating breathing apparatus, the residual oxygen pressure in the apparatus cylinder, which ensures the return of the person working to an area free of gas contamination, shall be monitored. The duration of work in breathing apparatus without a break shall not exceed thirty minutes. The time of work in oxygen-isolating breathing apparatus shall be recorded in its passport.
184. The air intake nozzles of hose breathing apparatus shall be positioned on the windward side and secured. Where there is no forced air supply by a fan, the length of the hose shall not exceed fifteen metres. The hose shall have no kinks or pinch points. Breathing apparatus is checked for tightness before the work is performed by pinching the end of the corrugated breathing tube.
185. During operation, regular checking of the sound condition of individual work safety systems shall be ensured in accordance with the operating documentation, as well as timely replacement of elements, components or subsystems whose protective properties have deteriorated, in accordance with the requirements of the operating documentation (operating instructions) of the manufacturers.