5.1.1. To control operation and ensure safe operating conditions, vessels, depending on their purpose, must be equipped with:

• shut-off or shut-off and control valves;
• devices for measuring pressure;
• instruments for measuring temperature;
• safety devices;
• liquid level indicators.

5.1.2. Vessels equipped with quick-release lids must have safety devices that prevent the vessel from being turned on under pressure if the lid is not completely closed and opening it when there is pressure in the vessel. Such vessels must also be equipped with locks with a key mark.

5.2. Shut-off and shut-off and control valves

5.2.1. Shut-off and shut-off and control valves must be installed on fittings directly connected to the vessel, or on pipelines supplying the vessel and discharging the working medium from it. In the case of a series connection of several vessels, the need to install such fittings between them is determined by the project developer.

5.2.2. The fittings must have the following markings:

• manufacturer's name or trademark;
• nominal diameter, mm;
• conditional pressure, MPa (working pressure and permissible temperature may be indicated);
• direction of medium flow;
• brand of body material.

5.2.3. The quantity, type of fittings and installation locations must be selected by the vessel project developer based on specific operating conditions and the requirements of the Rules.

5.2.4. The flywheel of the shut-off valve must indicate the direction of its rotation when opening or closing the valve.

5.2.5. Vessels for explosive, flammable substances, substances of hazard classes 1 and 2 according to GOST 12.1.007-76, as well as evaporators with fire or gas heating must have a check valve on the supply line from the pump or compressor, which is automatically closed by pressure from the vessel . A check valve must be installed between the pump (compressor) and the shut-off valves of the vessel.

5.2.6. Fittings with a nominal bore of more than 20 mm, made of alloy steel or non-ferrous metals, must have a passport of the established form, which must indicate data on the chemical composition, mechanical properties, heat treatment modes and the results of quality control of manufacturing using non-destructive methods.

Reinforcement that is marked, but does not have a passport, may be used after an inspection of the reinforcement, testing and verification of the grade of material. In this case, the owner of the valve must draw up a passport.

5.3. Pressure gauges

5.3.1. Each vessel and independent cavities with different pressures must be equipped with direct-acting pressure gauges. The pressure gauge is installed on the vessel fitting or pipeline between the vessel and the shut-off valve.

5.3.2. Pressure gauges must have an accuracy class of at least: 2.5 - at a vessel operating pressure of up to 2.5 MPa (25 kgf/cm2), 1.5 - at a vessel operating pressure above 2.5 MPa (25 kgf/cm2).

5.3.3. The pressure gauge must be selected with a scale such that the limit for measuring working pressure is in the second third of the scale.

5.3.4. The owner of the vessel must mark the pressure gauge scale with a red line indicating the operating pressure in the vessel. Instead of the red line, it is allowed to attach a metal plate painted red to the pressure gauge body and tightly adjacent to the glass of the pressure gauge.

5.3.5. The pressure gauge must be installed so that its readings are clearly visible to operating personnel.

5.3.6. The nominal diameter of the body of pressure gauges installed at a height of up to 2 m from the level of the observation platform must be at least 100 mm, at a height of 2 to 3 m - at least 160 mm.

Installation of pressure gauges at a height of more than 3 m from the site level is not permitted.

5.3.7. A three-way valve or a device replacing it must be installed between the pressure gauge and the vessel, allowing periodic checking of the pressure gauge using a control valve.

In necessary cases, the pressure gauge, depending on the operating conditions and the properties of the medium in the vessel, must be equipped with either a siphon tube, or an oil buffer, or other devices that protect it from direct exposure to the medium and temperature and ensure its reliable operation.

5.3.8. On vessels operating under pressure above 2.5 MPa (25 kgf/cm 2) or at ambient temperatures above 250 ° C, as well as with explosive atmospheres or hazardous substances of the 1st and 2nd hazard classes according to GOST 12.1.007- 76, instead of a three-way valve, it is allowed to install a separate fitting with a shut-off valve for connecting a second pressure gauge.

On stationary vessels, if it is possible to check the pressure gauge within the time limits established by the Rules by removing it from the vessel, the installation of a three-way valve or a device replacing it is not necessary.

On mobile vessels, the need to install a three-way valve is determined by the vessel design developer.

5.3.9. Pressure gauges and pipelines connecting them to the vessel must be protected from freezing.

5.3.10. The pressure gauge is not allowed for use in cases where:

• there is no seal or stamp indicating verification;
• the verification period has expired;
• when it is turned off, the arrow does not return to the zero scale reading by an amount exceeding half the permissible error for this device;
• the glass is broken or there is damage that may affect the accuracy of its readings.

5.3.11. Checking of pressure gauges with their sealing or branding must be carried out at least once every 12 months. In addition, at least once every 6 months, the owner of the vessel must carry out an additional check of the working pressure gauges with a control pressure gauge and record the results in the control check log. In the absence of a control pressure gauge, it is allowed to carry out an additional check with a proven working pressure gauge that has the same scale and accuracy class as the pressure gauge being tested.

The procedure and timing for checking the serviceability of pressure gauges by maintenance personnel during the operation of vessels should be determined by the instructions for the operating mode and safe maintenance of vessels, approved by the management of the organization that owns the vessel.

5.4. Temperature measuring instruments

5.4.1. Vessels operating at varying wall temperatures must be equipped with instruments to control the rate and uniformity of heating along the length and height of the vessel and benchmarks to control thermal movements.

The need to equip vessels with the specified instruments and benchmarks, as well as the permissible rate of heating and cooling of vessels, are determined by the project developer and indicated by the manufacturer in the vessel passport or in the operating manual.

5.5. Pressure protection devices

5.5.1. Each vessel (cavity of a combined vessel) must be equipped with safety devices against pressure increases above the permissible value.

5.5.2. The following are used as safety devices:

• spring safety valves;
• lever-weight safety valves;
• pulse safety devices (IPU), consisting of a main safety valve (MSV) and a direct-acting pulse control valve (IPC);
• safety devices with degradable membranes (membrane safety devices - MPU);
• other devices, the use of which has been approved by the Gosgortekhnadzor of Russia.

Installation of lever-weight valves on mobile vessels is not permitted.

5.5.3. The design of the spring valve must exclude the possibility of tightening the spring beyond the specified value, and the spring must be protected from unacceptable heating (cooling) and direct exposure to the working environment if it has a harmful effect on the spring material.

5.5.4. The design of the spring valve must include a device for checking the proper operation of the valve in operating condition by forcing it to open during operation.

It is allowed to install safety valves without a device for forced opening, if the latter is undesirable due to the properties of the medium (explosive, flammable, hazard classes 1 and 2 according to GOST 12.1.007-76) or according to the conditions of the technological process. In this case, checking the operation of the valves should be carried out on stands.

5.5.5. If the operating pressure of the vessel is equal to or greater than the pressure of the supply source and the possibility of an increase in pressure from a chemical reaction or heating in the vessel is excluded, then installing a safety valve and pressure gauge on it is not necessary.

5.5.6. A vessel designed for a pressure less than the pressure of the source supplying it must have an automatic reducing device on the supply pipeline with a pressure gauge and a safety device installed on the side of lower pressure after the reducing device.

If a bypass line is installed, it must also be equipped with a reducing device.

5.5.7. For a group of vessels operating at the same pressure, it is allowed to install one reducing device with a pressure gauge and a safety valve on the common supply pipeline up to the first branch to one of the vessels.

In this case, the installation of safety devices on the vessels themselves is not necessary if the possibility of pressure increase in them is excluded.

5.5.8. In cases where the automatic reducing device cannot operate reliably due to the physical properties of the working medium, it is permissible to install a flow regulator. In this case, protection against pressure increase must be provided.

5.5.9. The number of safety valves, their dimensions and capacity must be selected according to calculations so that a pressure does not build up in the vessel that exceeds the design pressure by more than 0.05 MPa (0.5 kgf/cm2) for vessels with a pressure of up to 0.3 MPa (3 kgf/cm2), by 15% - for vessels with pressure from 0.3 to 6.0 MPa (from 3 to 60 kgf/cm2) and by 10% - for vessels with pressure over 6.0 MPa ( 60 kgf/cm 2).

When safety valves are operating, the pressure in the vessel may be exceeded by no more than 25% of the operating pressure, provided that this excess is provided for by the design and is reflected in the vessel passport.

5.5.10. The capacity of the safety valve is determined in accordance with the ND.

5.5.11. The safety device must be supplied by the manufacturer with a passport and operating instructions.

The passport, along with other information, must indicate the valve’s flow coefficient for compressible and incompressible media, as well as the area to which it is assigned.

5.5.12. Safety devices must be installed on pipes or pipes directly connected to the vessel.

Connecting pipelines of safety devices (supply, discharge and drainage) must be protected from freezing of the working environment in them.

When installing several safety devices on one branch pipe (pipeline), the cross-sectional area of ​​the branch pipe (pipeline) must be at least 1.25 times the total cross-sectional area of ​​the valves installed on it.

When determining the cross-section of connecting pipelines with a length of more than 1000 mm, it is also necessary to take into account the value of their resistance.

Sampling of the working medium from the pipes (and in sections of connecting pipelines from the vessel to the valves) on which safety devices are installed is not allowed.

5.5.13. Safety devices must be placed in places accessible for their maintenance.

5.5.14. Installation of shut-off valves between the vessel and the safety device, as well as behind it, is not permitted.

5.5.15. The fittings in front of (behind) the safety device can be installed provided that two safety devices are installed and locked to prevent their simultaneous shutdown. In this case, each of them must have the capacity provided for in clause 5.5.9 of the Rules.

When installing a group of safety devices and fittings in front of (behind) them, the blocking must be done in such a way that, in case of any valve shutdown option provided for by the design, the remaining switched on safety devices have the total capacity provided for in clause 5.5.9 of the Rules.

5.5.16. The discharge pipelines of safety devices and impulse lines of the IPU in places where condensate may accumulate must be equipped with drainage devices to remove condensate.

The installation of shut-off devices or other fittings on drainage pipelines is not permitted. The media escaping from safety devices and drains must be diverted to a safe place.

Discharged toxic, explosive and fire-hazardous process media must be sent to closed systems for further disposal or to organized combustion systems.

It is prohibited to combine discharges containing substances that, when mixed, can form explosive mixtures or unstable compounds.

5.5.17. Diaphragm safety devices are installed:

• instead of lever-load and spring safety valves, when these valves cannot be used in the operating conditions of a particular environment due to their inertia or other reasons;
• in front of safety valves in cases where safety valves cannot operate reliably due to the harmful effects of the working environment (corrosion, erosion, polymerization, crystallization, sticking, freezing) or possible leaks through a closed valve of explosive and fire hazardous, toxic, environmentally harmful, etc. . substances. In this case, a device must be provided to monitor the serviceability of the membrane;
• in parallel with safety valves to increase the capacity of pressure relief systems;
• on the outlet side of the safety valves to prevent harmful effects of working media from the discharge system and to eliminate the influence of back pressure fluctuations from this system on the accuracy of the safety valves.

The necessity and location of installation of membrane safety devices and their design are determined by the design organization.

5.5.18. Safety membranes must be marked, and the marking must not affect the accuracy of operation of the membranes.

• name (designation) or trademark of the manufacturer;
• membrane batch number;
• membrane type;
• nominal diameter;
• working diameter;
• material;
• minimum and maximum response pressure of membranes in a batch at a given temperature and at a temperature of 20 °C.

The marking must be applied along the edge annular section of the membranes, or the membranes must be equipped with marking shanks (labels) attached to them.

5.5.19. Each batch of membranes must have a passport issued by the manufacturer.

• name and address of the manufacturer;
• membrane batch number;
• membrane type;
• nominal diameter;
• working diameter;
• material;
• minimum and maximum response pressure of membranes in a batch at a given temperature and at a temperature of 20 ° C;
• number of membranes in a batch;
• name of the regulatory document in accordance with which the membranes are manufactured;
• name of the organization according to the technical specifications (order) of which the membranes were manufactured;
• warranty obligations of the manufacturer;
• procedure for admitting membranes to operation;
• sample membrane operation log.

The passport must be signed by the head of the manufacturing organization, whose signature is sealed.

The passport must be accompanied by technical documentation for anti-vacuum supports, clamping and other elements, assembled with which the membranes of this batch are allowed for operation. Technical documentation is not attached in cases where the membranes are manufactured in relation to the fastening units already available to the consumer.

5.5.20. Safety membranes must be installed only in the mounting points intended for them.

Assembly, installation and operation of membranes must be carried out by specially trained personnel.

5.5.21. Safety membranes of foreign manufacture, manufactured by organizations not controlled by the Gosgortekhnadzor of Russia, can be allowed for operation only if there are special permits for the use of such membranes issued by the Gosgortekhnadzor of Russia in the manner established by it.

5.5.22. Membrane safety devices must be placed in places that are open and accessible for inspection and installation and dismantling, connecting pipelines must be protected from freezing of the working medium in them, and the devices must be installed on branch pipes or pipelines directly connected to the vessel.

5.5.23. When installing a membrane safety device in series with a safety valve (in front of or behind the valve), the cavity between the membrane and the valve must be connected by an outlet tube with a signal pressure gauge (to monitor the serviceability of the membranes).

5.5.24. It is allowed to install a switching device in front of membrane safety devices if there is a double number of membrane devices, while ensuring protection of the vessel from overpressure in any position of the switching device.

5.5.25. The procedure and timing for checking the serviceability of safety devices, depending on the conditions of the technological process, must be specified in the operating instructions for safety devices, approved by the owner of the vessel in the prescribed manner.

The results of checking the serviceability of safety devices and information about their settings are recorded in the shift log of the vessels by the persons performing the specified operations.

5.6. Liquid level indicators

5.6.1. If it is necessary to control the liquid level in vessels that have an interface between media, level indicators must be used.

In addition to level indicators, sound, light and other alarms and level locks can be installed on vessels.

5.6.2. Liquid level indicators must be installed in accordance with the manufacturer's instructions, and good visibility of this level must be ensured.

5.6.3. On vessels heated by flame or hot gases, in which the liquid level may drop below the permissible level, at least two direct-acting level indicators must be installed.

5.6.4. The design, number and installation locations of level indicators are determined by the developer of the vessel project.

5.6.5. Each liquid level indicator must be marked with acceptable upper and lower levels.

5.6.6. The upper and lower permissible levels of liquid in the vessel are set by the project developer. The height of the transparent liquid level indicator must be at least 25 mm below the lower and higher than the upper permissible liquid levels, respectively.

If it is necessary to install several height indicators, they should be placed so that they ensure continuity of liquid level readings.

5.6.7. Level indicators must be equipped with fittings (taps and valves) for disconnecting them from the vessel and purging them with the discharge of the working medium to a safe place.

5.6.8. When using glass or mica as a transparent element in level indicators, a protective device must be provided to protect personnel from injury when they rupture.

Pressure vessel fittings

from "Occupational Safety and Health at Oil Refineries and Petrochemical Plants"

Vessels and apparatus operating under pressure are equipped with the necessary shut-off, control and safety valves and special safety devices.
Shut-off valves are used to turn off and turn on lines supplying or discharging the working medium (valves, valves, plug valves).
Control valves, which include control valves, throttle and feed valves, serve to maintain specified operating parameters in a vessel or apparatus.
The protective fittings are designed to prevent pressure from increasing above the permissible value. This includes shut-off and protective (self-locking) valves installed on process pipelines and blocking the passage of gas in the event of unacceptable changes in its pressure, various safety, pressure-reducing and check valves.
Special safety devices include burst discs, breakaway valves, safety and locking devices for bayonet locks, etc.
To facilitate the opening of large-diameter valves that experience one-sided increased pressure on the sealing elements, especially with a general high pressure of the medium, the valves are equipped with a bypass valve with a nominal bore of 15-20 mm, equalizing the pressure on both sides of the valve before opening it.
Convenience and safety of servicing shut-off and control valves largely depend on the presence of pneumatic, hydraulic or electric drives that speed up and facilitate control of the valves. This is especially important when using large-sized fittings, their location in hard-to-reach places and high environmental pressure. An electric drive is especially necessary for the automatic supply of steam, gas or liquid to a high-pressure apparatus, when the control valves become a direct element of the automation system.
The purpose of pressure reducing valves is to reduce the pressure of steam, gas or liquid to the operating value established for the vessel, apparatus or pipeline.
Check valves allow liquid or gas to flow in only one direction. In particular, they are necessary when connecting devices and machines (compressors, pumps, gas blowers, fans, evaporators) in parallel, creating pressure in the system, since they prevent the unintended movement of a product under high pressure towards lower pressure.
There are two types of safety valves: lever and spring. Lever valves have a small capacity and, in addition, due to the absence of a closed exhaust, they discharge products directly into the surrounding atmosphere, which is not always acceptable. On devices under pressure from toxic and explosive substances, spring valves are usually installed. Such valves have a special flange at the outlet, through which they are connected to the exhaust pipe and then to the flare discharge or to the emergency tank. The spring in the valves is isolated from the body, thereby eliminating the possible harmful effects of high temperatures and the corrosive environment of the device.
According to the current technological instructions at oil refineries, most devices are equipped with two safety valves, a working (emergency) and a control one. It is prohibited to install any devices that create resistance to the discharge at the outlet of the service valve. The control valve discharges the product into a closed system; if necessary, separators, coolers, heating devices, etc. are installed along the discharge line with a total pressure loss of no more than 50 kN/m (0.5 kgf/cm). The valves are adjusted to the beginning of opening so that the control valve is activated first, and if it does not reduce the pressure to the working one, then the working valve begins to operate. This system significantly reduces product losses and reduces emissions into the atmosphere.
Reliable operation of safety valves is ensured by correct calculation of their throughput and precise adjustment. The throughput capacity of safety valves is determined according to the formula established by Gosgortekhnadzor.
The number of safety valves, their dimensions and capacity are selected so that a pressure cannot develop in the vessel that exceeds the operating pressure by more than 50 kN/m (0.5 kgf/cm) for vessels with a pressure of up to 300 kN/m (3 kgf/cm cm) inclusive, by 15% - for vessels with pressure from 300 kN/m to 6 MN/m (from 3 to 60 kgf/cm2) and by 10% - for vessels with pressure over 6 MN/m (60 kgf/cm2 ).
Safety valves are installed directly on the vessel; there should be no shut-off device between the valve and the vessel, otherwise the meaning of its use is lost. When one of the safety valves is removed for repair or inspection, a previously tested and prepared safety valve is immediately replaced in place of the removed one.
In general, the membrane assembly consists of the safety membrane itself and clamping rings fastened together with screws. There are rupture and release membranes. The first are dome-shaped shells, installed in the direction of pressure with a concave surface, the second - with a convex surface (Fig. 25 and Fig. 26). When a certain pressure is exceeded, the rupture disk must collapse and free up the flow area for the release of the medium. The release membrane, rigidly fixed along the edge, under the influence of pressure distributed along the convex side, loses stability and begins to bulge in the other direction. The buckling process progresses rapidly and leads to complete cracking of the shell. At critical pressure, the membrane is knocked out of the socket, and the passage hole is completely freed. With the same dimensions, made from the same material, release membranes operate at a pressure several times lower than bursting ones.
O - With fastening by a lens; b - with fastening by means of a lens and a conical holder.
To ensure the operation of the membrane, it is necessary to determine the value of the destruction pressure. By calculation it is possible to determine only the average value of the destruction pressure only very tentatively with a significant error. Therefore, the dimensions of the membranes and their destruction pressure have to be determined experimentally.
In case of discharge of toxic and explosive products, safety valves, membranes and other protective devices are equipped with special outlets for the release of gases and vapors into the atmosphere, into emergency tanks or into the flare line.
To monitor pressure, pressure gauges are placed on the vessels. The pressure gauge is checked at least once a year by a special organization and sealed or branded, in addition, an additional check is carried out by the company at least once every 6 months. The pressure gauge is not allowed for use if it does not have a seal or stamp on it or the inspection period has expired.

PB-03-576-03 requirements for materials

Appendix 4 PB-03-576-03 provides a list of steel grades and alloys used for the manufacture of cylinders, as well as a list of materials used for the manufacture of pressure vessels:

For sheet steel;

For steel pipes

For forgings;

For section steel;

For steel castings;

For fasteners

For non-ferrous metals and alloys

For cast iron castings

The notes to the tables state:

Thickness requirements;

Requirements for the scope and types of tests.

Eg,

Sheet steel

Steel grade, standard or specification designation	Technical requirements	Working conditions	Test types and requirements	Notes given at the end of the table
Wall temperature, °C	Medium pressure, MPa (kgf/cm 3), no more
St3sp, St3ps, St3kp2 GOST 380, GOST 14637	GOST 14637	From 10 to 200	1,6 (16)	GOST 14637	clause 1
St3sp, St3ps, St3Gps categories 3, 4, 5 depending on the operating temperature GOST 380, GOST 14637	GOST 14637 TU 14-1-3023 groups 1, 2	-0 to 425	5 (50)	GOST 14637 TU 14-1-3023	pp. 2, 4, 5, 7, 8
and other steel grades

Notes

1. Sheet thickness no more than 16 mm.

2. It is allowed to use sheet steel grades St3sp, St3ps category 3 with a thickness of no more than 40 mm; steel grades St3sp, St3ps categories 4 and 5 with a thickness of no more than 25 mm, steel grade St3Gps with a thickness of no more than 30 mm.

3. The scope and types of tests for steel grades 15 and 20 according to GOST 1577 must be carried out in accordance with GOST 5520 to the same extent as for steel grades 15K, 16K, 18K and 20K of the corresponding categories.

4. The mechanical properties of sheets less than 12 mm thick are checked on sheets taken from the batch.

5. A mechanical aging test is carried out if during the manufacture of vessels or their parts operated at temperatures above 200 degrees. C, steel is subjected to cold deformation (rolling, bending, flanging, etc.).

6. Sheets in accordance with GOST 19281 must be supplied with mandatory compliance with paragraphs. 2.2.1, 2.2.2, 2.2.3, 2.2.7, 2.2.9, 2.2.12 GOST, and the macrostructure must be monitored in accordance with GOST 5520 from a batch of sheets.

7. Tests are carried out sheet by sheet at operating temperatures below -30 degrees. C, above 200 degrees. With or at a pressure of more than 5 MPa (50 kgf/cm2) with a sheet thickness of 12 mm or more.

8. It is allowed to reduce the temperature limit for the use of carbon and low-alloy steels by 20 degrees. C (but not lower than -70 degrees C) for vessels with a wall thickness of up to 36 mm, if, when calculating the strength, the permissible stresses are reduced by at least 1.35 times and the vessel is heat treated.

If, when calculating strength, the permissible stresses are reduced by at least 2.85 times, then the temperature limit for the use of these steels can be reduced by 20 degrees. (but not lower than -70 degrees C) without heat treatment of the vessel.

And other notes.

clause 5.1. To conduct the technological process and ensure safe operating conditions, vessels, depending on their purpose, must be equipped with:

1. shut-off or shut-off and control valves,
2. devices for measuring pressure,
3. instruments for measuring temperature,
4. safety devices,
5. liquid level indicators.

clause 5.2. shut-off and shut-off and control valves

Shut-off and shut-off and control valves must be installed on fittings directly connected to the vessel, or on pipelines supplying the working medium to the vessel and discharging the working medium from it. When connecting several vessels in series, the number and location of installation of shut-off valves is determined by the designer.

The flywheel of the shut-off valve must indicate the direction of rotation when opening and closing the valve.

Vessels for explosive, flammable substances, substances of hazard classes 1 and 2, as well as evaporators with fire or gas heating must have a check valve on the supply line from the pump or compressor, which is automatically closed by pressure from the vessel. A check valve must be installed between the pump and the shut-off valves of the vessel.

Fittings made of alloy steels or non-ferrous metals with a nominal bore of more than 20 mm must have a passport indicating:

Chemical composition data;

Mechanical properties data;

Data on heat treatment modes;

Data on the results of manufacturing control using a non-destructive method.

clause 5.3. pressure gauges

Each vessel and independent cavities with different pressures must be equipped with direct-acting pressure gauges. The pressure gauge can be installed on a fitting of a vessel or pipeline up to the shut-off valve.

Pressure gauges must have an accuracy class of at least:

2.5 at P slave £2.5 MPa,

1.5 at P slave > 2.5 MPa

The pressure gauge must be selected so that the readings are in the second third of the scale.

On the pressure gauge scale, operating pressures are marked with a red line or a red metal plate is attached.

The pressure gauge must be installed so that the pressure readings are clearly visible to operating personnel.

The diameter of the pressure gauge body is set at the height:

Up to 2 m – at least 100 mm;

From 2 to 3 m – at least 160 mm;

It is not allowed to install a pressure gauge above 3 m.

If necessary, the pressure gauge, depending on the operating conditions, must be equipped with a siphon tube, an oil buffer or other devices that protect it from exposure to the working environment or temperature and ensure its reliable operation.

Pressure gauges and the pipelines on which they are installed must be protected from freezing.

Pressure gauges are not allowed for use in cases where:

1) there is no seal or stamp indicating that the inspection was carried out;

2) the inspection period has expired;

3) when turned off, its arrow does not return to zero;

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

Checking pressure gauges with their sealing or branding must be done at least once a year.

Once every 6 months, the owner of the vessel must check the working pressure gauge with a control pressure gauge.

clause 5.4. Temperature measuring instruments

Vessels operating at varying wall temperatures must be equipped with instruments to control the rate and uniformity of heating along the length and height of the vessel and benchmarks to control thermal movements.

The need to equip the vessel with temperature recording devices is determined by the project developers.

clause 5.5. Pressure protection devices

Each vessel must be equipped with a safety device (SD) to prevent pressure from increasing above the permissible value. The following are used as safety devices:

1. spring safety valves PPK;
2. lever-weight safety valves;
3. pulse safety devices (IPU), consisting of a main safety valve (GPV) and a direct-acting pulse control valve (IPC);
4. safety devices with destructive membranes (MPU);
5. other devices, the use of which has been approved by Rostekhnadzor.

The design of the PPK must exclude the possibility of tightening the spring beyond the established value, and the spring must be protected from unacceptable heating (cooling) and direct exposure to the working environment if it has a harmful effect on the spring material.

The design of the spring valve must include a device for checking the proper operation of the valve in operating condition by forcing it to open during operation.

It is allowed to install the control panel without a device for forced opening, if this is unacceptable due to the process conditions or if the environment is explosive, flammable, class 1 and 2. In this case, the valves are checked on stands. The frequency of these checks is set by the chief engineer.

If the operating pressure of the vessel is equal to or greater than the pressure of the supply source (P slave ³P pit) and the possibility of an increase in pressure from a chemical reaction or heating in the vessel is excluded, then installing a safety valve and pressure gauge on it is not necessary.

A vessel designed for a pressure less than the pressure of the source feeding it (P slave<Р пит), должен иметь редуцирующее устройство с манометром и предохранительным клапаном, установленными на стороне меньшего давления после редуцирующего устройства.

For a group of vessels operating at the same pressure (P slave = P feed), it is allowed to install one reducing device with a pressure gauge and safety valves on a common supply pipeline up to the first branch to one of the vessels. In this case, the installation of safety devices on the vessels themselves is not necessary if the possibility of pressure increase in them is excluded.

The number of safety valves and their capacity must be selected according to calculations in accordance with GOST 12.2. 085-82.

The manufacturer must supply the PU with a passport and operating instructions.

Configuration and adjustment of safety devices must be carried out in accordance with GOST 12.2.85-82.

PU must be installed on pipes or pipelines directly connected to the vessel. The connecting pipelines of the PU (supply, discharge, drainage) must be protected from freezing of the working environment in them.

Safety devices must be installed in places accessible for maintenance.

Installation of shut-off valves between the vessel and the safety device, as well as behind the safety valve, is not permitted.

The fittings in front of (behind) the safety device can be installed provided that two safety valves are installed and blocked to prevent their simultaneous shutdown.

The discharge pipelines of safety devices and impulse lines of the IPU in places where condensate may accumulate must be equipped with drainage devices to remove condensate.

Installation of shut-off valves or other fittings on drainage pipelines is not permitted. The media escaping from safety devices and drains must be diverted to a safe place.

Diaphragm safety devices are installed:

1. instead of lever-load and spring safety valves, when these valves cannot be used in the operating conditions of a particular environment due to their inertia or other reasons;
2. in front of safety valves in cases where safety valves cannot operate reliably due to the harmful effects of the working environment (corrosion, erosion, polymerization, crystallization, sticking and freezing) or possible leaks through a closed valve of explosive and fire hazardous environments, toxic and environmentally harmful environments. In this case, a device must be provided to monitor the serviceability of the membrane;
3. in parallel with a safety valve to increase the capacity of pressure relief systems;
4. on the outlet side of the safety valves to prevent the harmful effects of working media from the discharge system and to eliminate the influence of fluctuations in back pressure from this system on the accuracy of operation of the safety devices.

The necessity and location of installation of membrane safety devices and their design are determined by the design organization.

Each safety diaphragm must have a factory stamp with the specified response pressure and permissible operating temperature.

The passport is issued for the entire batch of membranes of the same type sent to one consumer.

To manufacture membranes, the enterprise must have permission from Rostechnadzor.

Safety diaphragms must only be installed in the clamping fixtures designed for them.

During operation, safety valves must be periodically checked for proper operation by purging them in operating condition or by testing them on a bench.

The procedure and timing for checking the serviceability of valves, depending on the conditions of the technological process, must be specified in the operating instructions for safety devices, approved by the chief engineer.

clause 5.6. Liquid level indicators

If it is necessary to control the liquid level in a vessel that has an interface between media, liquid level indicators must be used

In addition to the level indicator, vessels can be equipped with sound, light and other alarms and level blocking.

The design, number and installation locations of level indicators are determined by the developer of the vessel project.

Each level indicator must indicate the permissible upper and lower levels.

Level indicators must be equipped with fittings (taps and valves) to disconnect them from the vessel and purify them.

When a transparent glass or mica element is used in quality level indicators, a protective device must be provided to protect personnel from injury when they rupture.

Section 3. Rules for design and safe operation

Pipeline fittings

Moscow Standardinform 2010

Preface
The goals and principles of standardization in the Russian Federation are established by Federal Law No. 184-FZ of December 27, 2002 “On Technical Regulation”, and the rules for applying national standards of the Russian Federation are GOST R 1.0-2004 “Standardization in the Russian Federation. Basic provisions"

Standard information
1 DEVELOPED by the Closed Joint Stock Company "Research and Production Company "Central Design Bureau of Valve Manufacturing" (CJSC "NPF "TsKBA") and the Non-Profit Organization "Scientific and Industrial Association of Valve Manufacturers" (NO "NPAA")
2 INTRODUCED by the Technical Committee for Standardization TC 259 “Pipe fittings and bellows”
3 APPROVED AND ENTERED INTO EFFECT by Order of the Federal Agency for Technical Regulation and Metrology dated December 15, 2009 No. 1057-st
4 INTRODUCED FOR THE FIRST TIME
Information about changes to this standard is published in the annually published information index “National Standards”, and the text of changes and amendments is V monthly published information indexes “National Standards”. In case of revision (replacement) or cancellation of this standard, the corresponding notice will be published in the monthly published information index “National Standards”. Relevant information, notices and texts are also posted in the public information system - on the official website of the Federal Agency for Technical Regulation and Metrology on the Internet

NATIONAL STANDARD OF THE RUSSIAN FEDERATION
Pipeline fittings
GENERAL SAFETY REQUIREMENTS
Pipeline valves.
General safety requirements
dateintroduction - 2011-01-01

Application area

This standard applies to pipeline fittings and drive devices for them and establishes general safety requirements for their design, manufacture, installation, operation, repair, transportation, storage and disposal.

2 Normative references

This standard uses normative references to the following standards:
GOST R 8.568-97 State system for ensuring the uniformity of measurements. Certification of testing equipment. Basic provisions
GOST R 15.201-2000 System for developing and putting products into production. Products for industrial and technical purposes. The procedure for developing and putting products into production
GOST R EN 13463-1-2009 Non-electrical equipment intended for use in potentially explosive environments. Part 1. General requirements
GOST R 50891-96 Gearboxes for general machine-building applications. General technical conditions
GOST R 51317.2.4-2000 (IEC 61000-2-4-94) Electromagnetic compatibility of technical equipment. Electromagnetic environment. Electromagnetic compatibility levels for low-frequency conducted emissions in industrial power supply systems
GOST R 51330.0-99 (IEC 60079-0-98) Explosion-proof electrical equipment. Part 0. General requirements
GOST R 51901.12-2007 (IEC 60812:2006) Risk management. Method for analyzing failure modes and consequences
GOST R 52543-2006 (EN 982:1996) Volumetric hydraulic drives. Safety requirements
GOST R 52720-2007 Pipeline fittings. Terms and Definitions
GOST R 52760-2007 Pipeline fittings. Requirements for marking and distinctive coloring
GOST R 52857.1-2007 Vessels and apparatus. Norms and methods of strength calculations. General requirements
GOST R 52857.2-2007 Vessels and apparatus. Norms and methods of strength calculations. Calculation of cylindrical and conical shells, convex and flat bottoms and covers
GOST R 52857.3-2007 Vessels and apparatus. Norms and methods of strength calculations. Strengthening holes in shells and bottoms under internal and external pressure. Calculation of the strength of shells and bottoms under external static loads on the fitting
GOST R 52857.4-2007 Vessels and apparatus. Norms and methods of strength calculations. Calculation of strength and tightness of flange connections
GOST R 52857.5-2007 Vessels and apparatus. Norms and methods of strength calculations. Calculation of shells and bottoms from the impact of support loads
GOST R 52857.6-2007 Vessels and apparatus. Norms and methods of strength calculations. Calculation of strength under low-cycle loads
GOST R 52869-2007 (EN 983:1996) Pneumatic actuators. Safety requirements
GOST R 53402-2009 Pipeline fittings. Control and test methods
GOST R 53671-2009 Pipeline fittings. Gates and check valves. General technical conditions
GOST R 53673-2009 Pipeline fittings. Disk valves. General technical conditions
GOST R IEC 60079-0-2007 Explosive atmospheres. Part 0. Equipment. General requirements
GOST 2.601-2006 Unified system of design documentation. Operational documents
GOST 2.602-95 Unified system of design documentation. Repair documents
GOST 2.610-2006 Unified system of design documentation. Rules for the implementation of operational documents
GOST 9.908-85 Unified system of protection against corrosion and aging. Metals and alloys. Methods for determining corrosion indicators and corrosion resistance
GOST 12.0.004-90 System of occupational safety standards. Organization of occupational safety training. General provisions
GOST 12.1.007-76 System of occupational safety standards. Harmful substances. Classification and general safety requirements
GOST 12.1.012-2004 System of occupational safety standards. Vibration safety. General requirements
GOST 12.1.019-79 System of occupational safety standards. Electrical safety. General requirements and nomenclature of types of protection
GOST 12.1.044-89 (ISO 4589-84) System of occupational safety standards. Fire and explosion hazard of substances and materials. Nomenclature of indicators and methods for their determination
GOST 12.2.007.0-75 System of occupational safety standards. Electrical products. General safety requirements
GOST 12.2.052-81 System of occupational safety standards. Equipment working with oxygen gas. General safety requirements
GOST 12.2.085-2002 Pressure vessels. Safety valves. Safety requirements
GOST 12.3.009-76 System of occupational safety standards. Loading and unloading works. General safety requirements
GOST 12.3.019-80 System of occupational safety standards. Electrical tests and measurements. General safety requirements
GOST 27.002-89 Reliability in technology. Basic concepts. Terms and Definitions
GOST 356-80 Pipeline fittings and parts. Conditional, test and working pressures. Rows
GOST 1639-93 Scrap and waste of non-ferrous metals and alloys. General technical conditions
GOST 2171-90 Parts, products, semi-finished products and blanks made of non-ferrous metals and alloys. Brand designation
GOST 2787-75 Secondary ferrous metals. General technical conditions
GOST 5761-2005 Valves for rated pressure no more PN
GOST 5762-2002 Industrial pipeline fittings. Valves for rated pressure no more than PN 250. General technical conditions
GOST 9454-78 Metals. Impact bending test method at low, room and elevated temperatures
GOST 9544-2005 Pipeline shut-off valves. Valve tightness classes and standards
GOST 12893-2005 Single-seat, double-seat and cage control valves. General technical conditions
GOST 15150-69 Machines, instruments and other technical products. Versions for different climatic regions. Categories, operating, storage and transportation conditions regarding the impact of environmental climatic factors
GOST 19433-88 Dangerous goods. Classification and labeling
GOST 21345-2005 Ball, cone and cylindrical valves for rated pressure no more PN 250. General technical conditions
GOST 21744-83 Multilayer metal bellows. General technical conditions
GOST 30774-2001 Resource conservation. Waste management. Waste hazard certificate. Primary requirements
GOST 31294-2005 Direct acting safety valves. General technical conditions
Note - When using this standard, it is advisable to check the validity of reference standards and classifiers in the public information system - on the official website of the Federal Agency for Technical Regulation and Metrology on the Internet or according to the annually published information index “National Standards”, which was published as of January 1 of the current year, and according to the corresponding monthly information indexes published in the current year. If the reference standard is replaced (changed), then when using this standard you should be guided by the replaced (changed) standard. If the reference standard is canceled without replacement, then the provision in which a reference is made to it is applied in the part that does not affect this reference.

3Terms, definitions and abbreviations

3.1 This standard uses terms according to GOST R 52720, GOST 27.002, as well as the following terms with corresponding definitions:
3.1.1 valve safety: The condition of the valves in which there is no unacceptable risk associated with causing harm to the life or health of citizens, the property of individuals or legal entities, state or municipal property, the environment, the life or health of animals and plants, due to a critical failure of the valves or contact with the valves or its working environment with trouble-free operation of the valves.
3.1.2 test category: A type of test characterized by the organizational characteristics of its conduct and decision-making based on the results of assessing the object as a whole.
3.1.3 control tests: Tests carried out at various stages of the life cycle of valves in order to establish its compliance with the requirements of regulatory documents.
3.1.4 limit state criterion in relation to critical failure of reinforcement: A set of signs or a separate sign indicating the potential for a critical failure of the valve.
3.1.5 critical valve failure: Failure of fittings, the possible consequences of which will be harm to the life or health of citizens, property of individuals or legal entities, state or municipal property, the environment, life or health of animals and plants.
3.1.6 hazardous substances: Flammable, oxidizing, combustible, explosive, toxic, highly toxic substances and substances hazardous to the environment.
3.1.7 destination indicators: Basic technical data and characteristics of the valves that determine the possibility of its safe use in specific operating conditions.
3.1.8 reliability indicators: Indicators characterizing the ability of fittings to perform the required functions in given operating conditions.
3.1.9 limit state of reinforcement in relation to critical failures: The condition of the valve, upon reaching which its further operation is unacceptable due to the possibility of a critical failure.
3.1.10 probability of failure-free operation in relation to critical failures: The probability that within a given operating time (designated service life, designated resource) a critical failure of the valve will not occur.
3.1.11 system designer: A legal entity or individual entrepreneur who develops design and operational documentation for systems (production lines interconnected by the production cycle of the installation) in which valves are used.
3.1.12 valve developer: A legal entity or individual entrepreneur developing design and operational documentation for valves.
3.2 The following abbreviations are used in this standard:
AS - nuclear power plant;
Spare parts - spare tools and accessories;
KD - design documentation; PS - passport;
RE - operating manual;
TU - technical conditions;
ND - normative documentation;
ED - operational documentation.

4 Danger of fittings and safety measures

4.1 Danger of fittings

4.1.1 Valve can pose a danger both as a result of its critical failure and when it fails to perform its intended function.
4.1.2 The danger of harm to the life and health of citizens, the environment, the life and health of animals, the property of individuals and legal entities emanating from the valves as a result of its critical failure is:
- destruction of reinforcement;
- loss of tightness in relation to the external environment;
- destruction of the pipeline system due to failure of the fittings to perform their intended functions.
4.1.3 The danger of harm to the life and health of citizens, the environment, the life and health of animals, the property of individuals and legal entities, emanating from the valves when performing the function as intended without failure, is:
- causing harm as a result of exposure to them from fittings (thermal, chemical, radiation, electrical, mechanical hazards, noise, vibration);
- causing harm when valves are activated with the discharge of the working medium directly into the atmosphere (thermal, chemical, radiation, environmental, mechanical hazards);
- causing harm due to violation of safety precautions during the operation of the product.

4.2 Possible failures and limit state criteria

4.2.1 Potential failures of valves include:
- loss of strength of body parts and welds;
- loss of density of materials of body parts and welds;
- loss of tightness in relation to the external environment through seals of fixed (gasket and non-gasket) connections of body parts, moving connections (oil seals, bellows, membranes, etc.);
- loss of seal tightness beyond permissible limits;
- failure to perform functions as intended.
The criticality of a valve failure is determined by the designer of the system in which the valve is used, depending on the probability (frequency) of the failure and the severity of its consequences at the site of operation. Analysis of the types, consequences and criticality of failures is carried out in accordance with GOST R 51901.12.
4.2.2 The criteria for the limit state of reinforcement include:
- the initial stage of violation of the integrity of body parts (sweating, drip leak, gas leak);
- unacceptable change in the dimensions of elements according to the conditions of strength and functioning of the reinforcement;
- loss of tightness in detachable connections, which cannot be eliminated by tightening them with the calculated torque;
- occurrence of cracks on the main parts of the reinforcement;
- the presence of noise from the flow of the working medium through the valve or freezing (frost formation) on the body from the side of the outlet pipe when the valve is in the “closed” position, indicating leakage through the valve of the shut-off or safety valve;
- increase in torque when controlling valves to values ​​higher than the standards specified in Table 3, 6.1.7, ED and TU.
Limit states of reinforcement precede its failure.

4.3 Measures to ensure valve safety

4.3.1 The fittings must comply with the requirements of this standard, standards for specific types and types of fittings, design documentation and safety rules of federal supervisory authorities for systems in which the fittings are operated.
4.3.2 When ensuring the safety of valves at all stages of its life cycle, it is necessary:
- eliminate or reduce hazards to the extent reasonably practicable;
- use appropriate protective measures against hazards that cannot be avoided;
- inform system designers and valve users about residual hazards, indicating appropriate special measures to reduce them.
4.3.3 The safety of the valves in relation to various types of hazards associated with critical failures of the valves must be ensured:
- mechanical safety:
a) the use of materials for the main parts of valves operating under pressure, selected taking into account the parameters and operating conditions, as well as taking into account the danger posed by the working environment;
b) carrying out strength calculations using verified programs and providing the necessary safety margins for the main structural elements of the reinforcement, taking into account its operating conditions (working pressures, temperature of the working environment, climatic conditions, possible erosion and corrosive effects of the working environment, seismic and other external influences) ;
c) the use of components and parts, tested and/or tested design solutions;
d) the tightness of the fittings relative to the external environment;
- thermal safety:
a) tightness relative to the external environment;
b) carrying out assembly/installation in accordance with regulated procedures;
- chemical safety:
a) tightness relative to the external environment, selection and confirmation during testing for shut-off valves of the corresponding tightness class in the valve;
b) selection of safety margins for valves, taking into account the corrosion rate of materials of valve parts under pressure and in contact with the working environment;
c) confirmation of the strength and density of materials, welds and joints by testing;
- electrical safety:
a) design and use of electrical equipment for fittings in accordance with the indicators of purpose (in terms of voltage, type of current, etc.);
b) grounding of body parts of electrical equipment of fittings in compliance with the requirements of special rules;
- explosion proof:
a) the use of electrical equipment of the appropriate explosion protection level, confirmed in the prescribed manner;
b) the use of intrinsically safe materials of mating parts for fittings operating in explosive atmospheres;
c) provision in the design of devices for removing static electricity and removing stray ground currents;
- Fire safety:
a) the use of fire-resistant materials in the construction of reinforcement;
b) tightness relative to the external environment;
c) carrying out special tests for fire resistance;
- Industrial Safety:
a) designing the fittings in accordance with its functional purpose and taking into account the loads that may arise during its operation, establishing requirements for the reliability and safety of the fittings, taking into account ensuring the reliability and safety of the systems in which it will be operated;
b) development of ED (PS and OM, spare parts list);
c) establishment in the ED of indicators characterizing safety for valves, the failures of which under operating conditions are classified as critical;
d) introducing into the ED a list of possible critical failures and criteria for limit states of reinforcement;
e) the presence of mandatory markings;
f) carrying out the entire set of tests (preliminary, acceptance, etc.) confirming the required characteristics of the valves;
g) the level of technological processes for the manufacture of fittings and production control systems, ensuring the required indicators of failure-free operation of fittings;
h) organization and implementation of production control;
i) operation of valves in accordance with the requirements of ND and ED;
j) providing the consumer with information about the material composition of the product, types of heat treatment performed, hydraulic, pneumatic and mechanical tests and non-destructive testing performed;
- radiation safety:
a) tightness relative to the external environment, selection and confirmation during testing for shut-off valves of the corresponding valve tightness class;
b) selection of safety margins for the reinforcement according to calculations taking into account the corrosion rate of the materials of the reinforcement parts that are under pressure and in contact with the working environment.
4.3.4 The safety of valves in relation to various types of hazards not associated with valve failures must be ensured:
- mechanical safety:
a) the absence of sharp protruding parts and edges on the outer surfaces of the reinforcement;
b) protection of personnel from moving parts of valves and drives (actuators);
c) fastening the fittings to protect them from failure or displacement in the event of significant reactive forces from the discharged working medium, in the event of a likelihood of seismic impact on the fittings, as well as to relieve loads on the fittings from the influence of the pipeline;
- thermal safety:
a) thermal insulation of fittings or installation of fences, use of personal protective equipment for operating personnel for fittings installed in the serviced premises with a working environment temperature above 50 °C or below minus 40 °C;
b) a design that ensures a reduction in the temperature of the fittings in places of possible contact during maintenance. The temperature of the metal surfaces of the reinforcement in the presence of possible (unintentional) contact of an open area of ​​skin with them should be no lower than 4 ° C and no higher than 40 ° C;
- chemical safety:
a) the choice of materials used for the manufacture of parts and fittings that do not emit harmful chemicals in dangerous concentrations under normal operating conditions and in design emergency situations;
b) washing and use of personnel protective equipment during the process of maintenance, repair and disposal of fittings;
- electrical safety:
a) protection against electrostatic discharges if there is a danger of their occurrence;
b) periodic checks of insulation resistance;
- noise protection:
a) the design of the flow part of the valve, which reduces to the maximum possible extent the noise that occurs when the flow of the working medium passes through the valve valve;
b) the use of noise-absorbing sound insulation fittings;
c) the use of noise-absorbing sound insulation means for the premises in which the fittings are operated, and personal protective equipment for operating personnel;
- vibration protection:
a) the design of the flow part of the valve, reducing to the maximum possible extent the vibrations that occur when the flow of the working medium passes through the valve valve;
b) the use of devices that absorb vibration;
- radiation safety:
a) selection of non-radioactive materials for fittings;
b) decontamination of fittings during its repair and disposal and the maximum possible removal of decontamination solutions during external decontamination;
c) the use of personnel protection equipment during the process of maintenance, repair and disposal of valves.

5 Indicators of safety fittings

The specifications, design documentation and ED must contain indicators (characteristics) and technical requirements, the implementation of which will ensure the safety of the valves during the specified service life and resource, including:
- purpose indicators (including energy efficiency indicators);
- reliability indicators;
- indicators characterizing safety;
- possible failures and criteria for limit states.

5.1 Purpose indicators

5.1.1 The main indicators of the purpose of the fittings are:
- type of fittings (functional purpose) - in accordance with GOST R 52720;
- nominal diameter;
- nominal pressure (or operating pressure, or design pressure);
- name and parameters of the working environment:
a) chemical composition and phase (aggregate) state;
b) temperature range;
c) classification of the working environment according to GOST 12.1.007, GOST 12.1.044 according to the group of process pipelines according to and according to the category of steam and hot water pipelines according to;
- climatic version (with environmental parameters);
- explosion safety category;
- types and parameters of external influences (including seismic, fire);
- seal tightness;
- hydraulic characteristics (in accordance with Appendix B);
- response time (for shut-off valves);
- setting pressure (for safety valves).
Indicators of the energy efficiency of the valve are the hydraulic characteristics, the power characteristics of the valve (torque or force required for control), as well as the power of the electric motor (electromagnet) of the drive.

5.2 Reliability indicators

A.1 Calculation of reinforcement for strength is a mandatory part of the design documentation. For nuclear power plants or at the customer's request, a calculation or extract from the strength calculation is a mandatory document that is supplied along with the valve data sheet.
A.2 The calculation must contain quantitative justification for the strength, tightness and performance (functioning) of the reinforcement. The calculation justification for the strength of the reinforcement should be based on estimates for the following limit states:
- destruction of the part (ductile, brittle, under creep conditions);
- plastic deformation over the entire cross-section of the part;
- occurrence of a macrocrack during cyclic loading of a part;
- unacceptable change in the dimensions of elements according to the operating conditions of the reinforcement;
- loss of stability of the part;
- loss of tightness at fixed and movable joints (leakage that cannot be eliminated by tightening the joints with the calculated torque);
- loss of tightness in the valve (leakage that cannot be eliminated by the design force (torque) of the control);
- disruption of the functioning of the fittings.
A.3 When carrying out strength calculations of reinforcement, the following loads and impacts must be taken into account:
- design pressure;
- design temperature;
- parameters of the working environment in non-stationary modes (limits of changes in pressure and temperature of the medium, rate of change and number of cycles);
- pressure test parameters;
- maximum loads acting on the valves in case of violation of normal operating conditions and in emergency situations;
- loads transmitted from the pipelines to the pipes and to the places where the fittings are attached to the building structure;
- seismic, shock and vibration loads, dynamic effects of moving parts;
- other loads and impacts that have a significant impact on the strength, tightness and performance of the fittings.
A.4 The calculation should include the following sections:
- determination of the forces and moments required to ensure the tightness of the valve assembly and to control the valves (force calculation of the valves);
- determination of the forces and moments required to ensure the tightness of detachable connections of fittings in operating and testing modes (force calculation of detachable connections);
- determination of the minimum wall thicknesses of valve elements operating under pressure (body, cover, fasteners);
- verification calculation of components and parts of reinforcement, including the following assessments: static strength, cyclic strength, long-term static strength, long-term cyclic strength, seismic strength, vibration strength, resistance to brittle fracture, stability (the need to perform one or another section of the verification calculation is determined during the calculation depending on on the design, operating parameters and purpose of the fittings).
A.5 Strength calculations are performed in accordance with the requirements of strength calculation standards in force in the relevant industry, for example: GOST R 52857.1, GOST R 52857.2, GOST R 52857.3, GOST R 52857.4, GOST R 52857.5, GOST R 52857.6, , , , . In the calculations, general engineering or special verified (and/or certified) calculation methods and (or) computer calculation programs are used.
A.6 The minimum wall thicknesses of valve elements operating under pressure are determined taking into account the design pressure and design temperature. The minimum wall thicknesses of elements are determined without taking into account the deposited or cladding layer. The minimum wall thicknesses of elements are determined taking into account the negative tolerances provided for in the design documentation, possible technological tolerances, as well as allowances for the corrosive and erosive influence of the environment. The minimum wall thickness of the element is determined from the condition that the total membrane stresses in the element do not exceed the nominal value of the permissible stress.
A.7 When determining the rated permissible stress, the following characteristics of the material at the design temperature are taken into account:
- conditional yield strength corresponding to a permanent elongation of 0.2%, Rр 0,2;
- conditional yield strength corresponding to a permanent elongation of 1.0%, Rр 0,1;
- minimum value of temporary resistance Rm;
- creep limit (average 1% value of creep limit over 105 hours for reinforcement operating under creep conditions)
- long-term strength limit (the average value of the tensile strength over 105 hours for reinforcement operating under creep conditions),
- Young's modulus (elastic modulus) E;
- Poisson's ratio µ;
- the magnitude of plastic deformation at fracture δ.
Safety factors are taken in accordance with the strength calculation standards in force in the relevant industry, but they must be no less than the following values:
- yield strength 1.5;
- tensile strength 2.4;
- according to the long-term strength limit 1.5;
- creep limit 1.0.
A.8 The verification calculation considers all loads acting on the reinforcement in normal operation modes, violations of normal operation and in emergency situations, including those specified in A.3.
The need to take into account a particular load in the calculation is determined by the designer (calculator) depending on the value and conditions of the load, the type of calculation, the design and purpose of the reinforcement.

Appendix B
(required)

Pipeline fittings. Welding and quality control of welded joints. Technical requirements

Rules for the design and safe operation of process pipelines

Industrial pipeline fittings. Method for determining the dimensions of handwheels and handles

52] ST TsKBA 072-2009

Pipeline fittings. Torques and dimensions of handwheels and handles

Maintenance and repair of vessels operating under excess pressure over 0.07 MPa (dust collectors, filters, separators, heat exchangers, etc.) and controlled by Gosgortekhnadzor must be carried out in accordance with the requirements for the safe maintenance of vessels specified in the "Rules for the design and safe operation of vessels, working under pressure", 1987

Deviation from these “Rules” may be allowed only in exceptional cases with the permission of the USSR State Mining and Technical Supervision. A copy of the permission (to change the design, material, installation location, etc.) to deviate from the “Rules” must be attached to the vessel passport.

These “Rules” are mandatory for all officials and engineering and technical workers involved in the design, manufacture, installation, repair and operation of vessels.

Vessels should be installed in open areas in places where there are no crowds of people. The installation of vessels must provide the opportunity to inspect, repair and clean them from the inside and outside.

For ease of maintenance, platforms and stairs should be installed that do not interfere with the strength and stability of the vessel. Vessels operating under pressure above 0.07 MPa must be registered with the Gosgortekhnadzor authorities before they are put into operation.

The management of the enterprise is obliged to ensure that the vessels are maintained in good condition and their operating conditions are safe. The orders must be appointed from among the engineering and technical workers who have passed the test of knowledge of these “Rules” in the prescribed manner, responsible for the good condition and safe operation of the vessels, as well as those responsible for supervising the technical condition and operation of the vessels.

Technical inspection is carried out by an inspector of Gosgortekhnadzor in the presence of a person responsible for the good condition and safe operation of the vessels, and the following is carried out:

Internal inspection once every 4 years;

Hydraulic testing once every 8 years with a test pressure of 1.25 P working.

Vessels operating under pressure are subject to early technical inspection in the presence of an inspector from Gosgortekhnadzor:

After reconstruction and repair using welding of elements working under pressure;

If before they were put into operation they were inactive for more than one year;

If the vessel has been dismantled and installed in a new location;

If such an examination is necessary at the discretion of the inspector, the person exercising supervision or the person responsible for the good condition and safe operation of the vessel.

Before inspection, the vessel must be freed from condensate and dirt (blown through a drainage device), stopped, disconnected with plugs from all pipelines connecting the vessel to pressure sources, and the gas must be vented; Before hydraulic testing, all fittings must be thoroughly cleaned, taps and valves must be ground in, hatches must be tightly closed.

After installation and registration, the following is applied to each vessel with paint in a visible place or on a special plate with a format of at least 200x150 mm:

Registration number;

Allowed pressure;

Date of next inspection and hydraulic test.

Maintenance and repair of pressure vessels.

To ensure normal operating conditions, the above vessels must be equipped with:

Instruments for measuring pressure and temperature of the medium;

Safety devices;

Shut-off valves.

Each vessel is equipped with at least one safety valve, which eliminates the possibility of an arbitrary increase in the pressure of the medium in the vessel. Safety valves are set to a pressure equal to 1.15 Rwork.

Shut-off valves installed on vessels are designated:

Conditional passage;

Conditional pressure;

Direction of medium flow.

Installation of shut-off valves between vessels and the safety valve is prohibited.

Shut-off valves are installed on the inlet and outlet pipelines of each vessel. Each vessel must be equipped with a pressure gauge installed on the fitting of the vessel body or on the pipeline to the shut-off valve. Pressure gauges must have an accuracy class of at least 2.5 and be selected with a scale such that the operating pressure measurement limit is in the second third of the scale.

Install the pressure gauge so that its readings are clearly visible to maintenance personnel. Check pressure gauges with their sealing or branding at least once every 12 months, in addition, at least once every 6 months, additionally check working pressure gauges with a control pressure gauge and record the results of control checks in the journal. Pressure gauges are not allowed for use in cases where:

There is no seal or mark;

The verification period has expired;

When it is turned off, the pressure gauge needle does not return to the zero scale mark by an amount exceeding half the permissible error;

The glass is broken or there is other damage that may affect the accuracy of its readings.

While the unit is operating, monitor instrument readings and record them in the operational log. The cause of any abnormal deviation in instrument readings must be immediately investigated so that appropriate action can be taken.

Blow the separator at least once a day, in winter - once a shift.

Complete cleaning of the separators should be carried out once a year according to the schedule of preventive maintenance of gas distribution stations equipment, approved by Ch. hospital engineer.

Drainage of condensate from the PU must be carried out in special containers with its subsequent transportation outside the GDS. Spilling condensate onto the ground is not allowed. In the event of a condensate spill, soil saturated with condensate is removed from the GDS territory. Devices (separators) and pipelines under pressure may only be heated with hot water or steam. Under pressure it is prohibited:

1. tighten any screw connections or flange bolts;

2. hit the vessel and fittings;

3. heat vessels or other equipment with an open fire. Repair of vessels and its elements during operation is not allowed. If defects are identified that threaten the safe operation of the vessel or the period for the next inspection has expired, the operation of the vessel is prohibited, and the reason for the prohibition is recorded in the vessel passport. The vessel must be stopped:

When the pressure in the vessel increases above the permitted limit;

If the safety valves are faulty;

If cracks, bulges, significant thinning of the walls, gaps or sweating, in welds, rupture of gaskets are detected in the main elements of the vessel;

If a fire occurs that directly threatens the pressure vessel;

If the pressure gauge malfunctions and it is impossible to determine the pressure using other devices;

In case of malfunction or incomplete quantity of fasteners of flanges, covers and hatches.

When opening, inspecting and cleaning the dust collector, the internal surfaces should be generously moistened with water to prevent spontaneous combustion of possible pyrophosphoric iron deposits, having thoroughly steamed the dust collector before this and measured the gas content.

Uninterrupted operation of gas purification units at gas distribution stations is achieved by proper organization of repair and maintenance work. The latter are usually held in the summer and include:

Current repairs (provided once a year) - external and internal inspections, cleaning vessels from contaminants, washing Raschig rings, replacing filter material, inspecting shut-off valves to eliminate oil and gas leaks;

Medium repair (after 4 years) - partial replacement of contact tubes in dust collectors, as well as repair and replacement of shut-off valves;

Overhaul - repair of vessel bodies, replacement of contact tubes in dust collectors, replacement of nozzles made of Raschig rings.