What functional responsibilities will you have if you increase your rank?
Answer: According to ETKS (unified tariff - qualification directory) by rank
What is AGZU and what is it intended for?
Answer: An automatic group metering unit (AGZU) is designed to measure the average daily volumetric flow rate of gas and to determine the average daily mass flow rate of oil produced from oil wells in automatic and manual modes.
What is SPVK, explain what it is for, what pressure it is calibrated for, calibration dates, what is written on the valve tag?
Answer: SPPK (special spring- safety valve) is designed to relieve excess pressure.
The frequency of calibration should be no less than every 24 months.
Each valve must have...
the sign is securely attached and sealed of stainless steel or aluminum, on which are stamped:
a) serial number of the valve;
b) valve setting pressure – Rust (operation pressure);
c) date of (actual) last inspection and calibration.
SPPK is calibrated to 1,15 Rrab.
Additionally, a red arrow is applied to the valve body, indicating the direction of movement of the lever when the valve is detonated.
What is written on information plate SRD? Timing of hydrotesting of vessels, what pressure is used for hydrotesting?
Answer: After installation, each vessel must be painted in a visible place or on a special plate with a format of at least 150x200 mm:
- registration number;
— permitted pressure;
- date, month and year of the next external inspection and hydraulic test
External inspection and hydraulic tests (NO and GI) are carried out after 2 years
Hydrotesting of vessels is carried out 1,25 Rrab
Why are pressure gauges needed, what types are there? Requirements for pressure gauges, for what reasons pressure gauges are rejected, what is written on the stamp (seal), accuracy class of the pressure gauge, what is checking and calibrating the pressure gauge, the timing of their implementation, selection of the pressure gauge depending on the pressure, what diameter will the pressure gauge be installed at a height of 2 -x up to 3 meters? I-08 is stamped on the seal (stamp), until what day is it subject to use?
Answer: A pressure gauge is a device that measures pressure.
Each vessel and independent cavities with different pressures must be equipped with pressure gauges direct action. The pressure gauge can be installed on a vessel or pipeline fitting up to shut-off valves.
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/cm 2);
1.5 – at a working pressure of the vessel above 2.5 MPa (25 kgf/cm2).
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.
The pressure gauge scale should have a red line indicating the maximum 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.
The pressure gauge must be installed so that its readings are clearly visible to operating personnel.
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.
The pressure gauge is not allowed for use in cases where:
— there is no seal or stamp with a mark on the state verification;
— the state 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 of this device;
- the glass is broken or there is damage that may affect the accuracy of its readings.
Verification pressure gauges with their sealing or branding is carried out at least once every 12 months.
In addition, at least once every 6 months, the owner of the vessel must make additional check working pressure gauges with a control pressure gauge with recording of the results in the log of control checks of pressure gauges. In the absence of a control pressure gauge, it is allowed to carry out an additional check with a working pressure gauge that has the same scale and class as the pressure gauge being tested.
I-08 is stamped on the seal (stamp), until what day is it subject to use? Until 01/01/2009
Share with friends: Question:
Dear experts, please explain what specific regulations technical documents we need to be guided when testing (calibrating) safety valves, since in the "Rules for the Design and safe operation process pipelines(approved by Resolution of the State Mining and Technical Supervision of the Russian Federation dated June 10, 2003 N 80) clause 9.3.31. It is stated that “Safety valves are maintained in accordance with technical documentation and regulatory and technical documentation for industrial safety,” i.e. No detailed answer has been given on this issue. And the second question is whether we have the right to be guided by IPKM-2005 “Procedure for operation, inspection and repair of safety valves, membrane safety devices of oil refining and petrochemical enterprises of the Ministry of Industry and Energy of Russia”, agreed with Rostechnadzor of Russia, to determine the frequency of revision of the control panel.
Best regards, Makarov E.
Answer:
Hello. Calibration is carried out on the basis of the factory
Operating manuals (instructions).
PB 03-583-03 also applies for membrane devices.
There are no similar PBs in the oil and gas industry. It is possible to use the “Operating Procedures...” you specified, if it applies to the oil and gas industry.
Ticket No. 8
Requirements for the safe performance of work when conducting hydraulic testing of the hydraulic control system in the VNK.
1. Hydraulic testing is aimed at checking the strength of the vessel elements and the tightness of the joints. Vessels must be submitted for hydraulic testing with fittings installed on them.
4.2. Hydraulic testing of vessels is carried out only if the results of external and internal examinations are satisfactory.
4.3. Fill the vessel with water. When filling a vessel with water, the air must be completely removed. For hydraulic testing of vessels, water with a temperature not lower than +5ºС and not higher than + 40ºС should be used, if technical conditions no specific temperature value allowed under the condition of preventing brittle fracture is indicated. The temperature difference between the vessel wall and the surrounding air during testing should not cause moisture condensation on the surface of the vessel walls. By agreement with the vessel design developer, another liquid can be used instead of water.
4.5. The pressure in the vessel should be increased gradually. The rate of pressure rise must be specified in the installation and operating instructions.
The use of compressed air or other gas to increase pressure is not permitted.
The test pressure must be monitored by two pressure gauges, one of which must be installed at top cover(bottom) of the vessel. Both pressure gauges must be of the same type, measurement limit, same accuracy classes, and division values.
4.6. Maintain the vessel under test pressure for 5 minutes, unless otherwise specified by the manufacturer.
4.7. Reduce the pressure to the design (permitted) value and inspect the outer surface of the vessel, all its detachable and welded connections.
Tapping the walls of the body, welded and detachable joints of the vessel during testing is not allowed.
4.8. The vessel is considered to have passed the hydraulic test if the following is not detected:
Leaks, cracks, sweating tears in welded joints and in the base metal;
Leaks in detachable connections;
Visible residual deformations, pressure drop on the pressure gauge.
4.9. The vessel and its elements in which defects are identified during testing are subjected to repeated hydraulic tests with test pressure after their elimination.
In cases where a hydraulic test is not possible, it is permitted to replace it with a pneumatic test (air or inert gas). This type of test is allowed subject to its control by the acoustic emission method (or another method approved by the State Mining and Technical Supervision Authority of Russia).
During pneumatic testing, precautions are taken: the valve on the filling pipeline from the pressure source and pressure gauges are taken outside the room in which the vessel being tested is located, and people are removed to a safe place during the test pressure test of the vessel.
Frequency of SPPK calibration.
Along with the technical examination of the vessels, safety valves must be calibrated (at least once every 2 years). The number of safety valves, their dimensions and capacity must be selected according to calculations so that pressure does not build up in the vessel exceeding the excess pressure by more than 0.05 MPa (0.5 kgf/cm2) for vessels with pressure 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/cm2). The calibration pressure of safety valves is determined based on the permitted pressure in the vessel.
At what pressure is the SPPK calibrated?.
The number of safety valves, their sizes and capacity must be selected according to calculations so that vessel pressure was not created exceeding the design one by more than 0.05 MPa (0.5 kgf/cm2) for vessels with pressure 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 above 6.0 MPa (60 kgf/cm2).
When safety valves are operating, it is allowed to exceed the pressure in the vessel by no more than 25% of the working pressure, provided that this excess is provided for by the design and is reflected in the vessel passport.
The procedure for preparing a vessel for inspection.
The person responsible for good condition and safe operation must ensure the preparation of the vessel for technical inspection and participate in it.
2.1. Work inside the vessel must be carried out in accordance with the work permit.
2.2. Before internal inspection and hydraulic testing, carry out the following
current works:
Stop the vessel;
Cool (warm);
Free from the environment that fills it;
Disconnect plugs from all pipelines connecting the vessel to a pressure source or other vessels;
Steam with live steam until the hydrocarbon content is below 300 mg/m 3 and the oxygen content is less than 20% by volume;
Clean the vessel down to metal.
Vessels working with harmful substances 1st and 2nd hazard classes according to GOST 12.1.007, before starting any work inside, as well as before internal inspection, they must undergo mandatory processing (neutralization, degassing) in accordance with instructions for the safe performance of work, approved by the chief engineer .
Lining, insulation and other forms of corrosion protection must be partially or completely removed if there are signs indicating the possibility of material defects. power elements vessel structures (lining leaks, lining holes, traces of insulation being wet, etc.). Electrical heating and the vessel drive must be turned off;
Remove devices that impede external and internal inspection of vessels (coils, stirrers, jackets, plates, etc.).
The possibility of removing welded devices and their subsequent installation in place must be indicated in the technical documentation and in the “Installation and Safe Operation Instructions” of the plant.
manufacturer;
Before inspection, vessels with a height of more than 2 m must be equipped with the necessary devices to ensure safe access to all parts of the vessel.
4.In what cases is it permissible to install shut-off valves between the SRD and PPK.
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 clause 5.5.9 Rules
When installing a group of safety devices and fittings in front of (behind) them, the blocking must be performed 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.What data is applied by the manufacturer to the DDS? ,
What data is applied by the manufacturer to the DDS.
The manufacturer puts the following data on the DDS:
Manufacturer's name;
Name of the vessel;
Design, test and working pressure;
Mass and volume;
Date of manufacture.
Figure 3.1. - Manufacturer's data
Council of Chief Mechanics of Enterprises
oil refining
and petrochemical industry
INSTRUCTIONS. IPKM-2005
“Procedure for operation, inspection and repair
spring safety valves,
membrane safety
oil refining devices
and petrochemical enterprises
Ministry of Industry and Energy of Russia"
Moscow 2006
COUNCIL OF CHIEF MECHANICS OF ENTERPRISES
OIL REFINING AND PETROCHEMICAL
INDUSTRY
PUBLIC CORPORATION
"ALL-RUSSIAN RESEARCH
AND DESIGN AND TECHNOLOGICAL INSTITUTE
EQUIPMENT FOR OIL REFINING AND
PETROCHEMICAL INDUSTRY"
(JSC "VNIKTIneftekhimoborudovanie")
Instructions. IPKM-2005
“Procedure for operation, inspection and repair of spring
safety valves, diaphragm safety valves
devices of oil refining and petrochemical enterprises
Ministry of Industry and Energy of Russia"
Volgograd - 2006
On review of regulatory and technical documentation
The Directorate for Supervision of Oil and Gas Production, Refining and Main Pipeline Transport Facilities reviewed the instructions ((Procedure for operation, inspection and repair of spring safety valves, membrane safety devices of oil refining and petrochemical enterprises of the Ministry of Industry and Energy of Russia" (IPKM-2005), approved by the Chairman of the Council of Chief Mechanics of Enterprises oil refining and petrochemical industry on January 23, 2006, minutes of a technical meeting to review the said instructions dated September 30, 2005 with the participation of specialists from oil refining and petrochemical enterprises and specialists from VNIKTIneftekhimoborudovanie OJSC, comments from NIIKHIMMASH OJSC to the instructions (letter dated April 26, 2006 No. 7064-31-5-31) and changes and clarifications made to the instructions of OJSC “VNIKTIneftekhimoborudovanie” (letter dated June 19, 2006 No. 13/731) and reports the following.
In accordance with Article 17 of the Federal Law of December 27, 2002 No. 184-FZ“On technical regulation” standards of organizations, including public ones, are developed independently, in accordance with the requirements of national norms and rules and are not subject to approval by Rostechnadzor.
The submitted document does not contradict the requirements of national norms and regulations. It is industrial safety and can be used as a recommendation document for organizations operating hazardous production facilities in the oil refining and petrochemical industries instead of a guidance document RUPC-78
Preface
1. DEVELOPED by the Open Joint Stock Company "VNIKTIneftekhimoborudovanie" taking into account proposals from oil refining and petrochemical enterprises of the Ministry of Industry and Energy of Russia.
DEVELOPERS:
A.E. Foliyants; N.V. Martynov; Yu.I. Shleenkov; N.N. Tolkachev; A.E. Starodubtsev; G.V. Gorlanova; S.V. Evgrafova; N.S. Goleva - OJSC "VNIKTIneftekhimoborudovanie";
A.A. Shatalov - Federal Service for Environmental, Technological and Nuclear Supervision;
B.S. Kabanov, V.L. Sokolov - LLC PA "Kirishinefteorgsintez",
S.O. Malikov - Lennihimmash LLC.
2. Put into effect by order of the enterprise.
3. With the entry into force of the “Instructions” the action is canceled RUPC-78“Guidelines for the operation, inspection and repair of spring safety valves.”
4. These instructions are mandatory for all enterprises in the oil refining and petrochemical industries.
1 area of use
1.1 This instruction provides for the procedure for operation, supervision, inspection and repair of spring safety valves (SPV), membrane safety devices (MPD) installed or installed on vessels, apparatus, pipelines, pumps, compressors and other types of equipment of oil refining and petrochemical enterprises of the Ministry of Industry and Energy of Russia.
1.2 The instructions do not apply to safety valves of steam boilers, steam superheaters and economizers with an operating pressure of more than 0.07 MPa (0.7 kgf/cm 2) and hot water boilers with water temperatures above 115 °C, which are subject to the “Rules for Construction and safe operation of steam and hot water boilers", as well as safety valves of steam and hot water pipelines with a working steam pressure of more than 0.07 MPa (0.7 kgf/cm 2) or hot water with water temperatures above 115 °C, which are subject to PB 10-573-03.
2 Normative references
3.1.7 Diaphragm safety device(MPU) - a device consisting of a bursting safety membrane (one or more) and its fastening unit (clamping elements) assembled with other elements, providing the necessary release of the mass of the working medium at a certain response pressure.
3.1.8 MPU vacuum- a special membrane safety device used in cryogenic tanks and pipelines to protect the thermal insulation cavity from increased pressure in an emergency.
3.1.9 Safety membrane (MP)- MPU safety element, which collapses at a given pressure and frees up the necessary flow area for communication of the protected vessel (pipeline) with the discharge system.
3.1.10 Bursting membrane (MR)- flat or dome-shaped MP, working to break under the pressure acting on its surface.
3.1.11 Flapping membrane (MX)- dome-shaped MP. working to lose stability (clap) under pressure acting on a convex surface. Losing stability, the membrane is cut using knife blades or torn along a previously weakened section.
3.1.12 Clamping elements- parts used to secure (clamp) the MP along the edge annular section.
3.1.13 Nominal diameter DN (DN)- nominal internal diameter of the pipeline connected to the fittings;
3.1.14 Conditional pressure Ru (PN)- the highest excess pressure at a medium temperature of 293K (20 °C), at which long-term operation of vessels, fittings and pipeline parts having specified dimensions, justified by strength calculations for the selected materials and their strength characteristics corresponding to a temperature of 293K (20 °C) is permissible ;
3.1.15 Internal (external) pressure- pressure acting on the inner (outer) surface of the vessel wall.
3.1.16 Design pressure of the vessel (apparatus), pipelineR race- excess internal or external pressure for which the strength is calculated *
3.1.17 Permitted pressure of the vessel (apparatus), pipeline P times- maximum excess permissible internal or external pressure, established based on the results of technical examination or technical diagnostics.*
3.1.18 Operating pressure vessel (apparatus), pipeline R slave- excessive maximum internal or external pressure that occurs during the normal course of the technological process (pressure, temperature of the working medium, etc.) without taking into account the hydrostatic pressure of the working medium and without taking into account the permissible short-term excess pressure during the operation of the safety valve or other safety devices*.
*Note. Operating, permitted and design pressures are assigned from the condition R slave ≤ P times ≤ R race.
3.1.19 Design temperature of the wall of the vessel (apparatus), pipeline T races- the highest wall temperature at which permissible stresses are determined and strength calculations are carried out.
3.1.20 Operating temperature of the wall of the vessel (apparatus), pipeline T slave- wall temperature that occurs during the normal course of the technological process.
3.1.21 Permitted temperature of the vessel, pipeline T size- operating temperature at the permitted pressure, established based on the results (pipeline inspection) or technical diagnostics;
3.1.22 Set pressure (opening pressure) of the safety valvePvcm- excess pressure at which the safety valve will make the first clap during adjustment on the bench compressed air(adjusting spring pressure) or begins to lose seal in the valve when tested with water.
3.1.23 Safety valve full opening pressure P 1 - excessive maximum pressure in front of the safety valve when it reaches its full opening.
3.1.24 Pressure behind safety valve R 2 - excess pressure directly at the outlet of the exhaust fitting of the safety valve.
3.1.25 Excessive pressure in the relief system R Sat - maximum pressure in the discharge manifold (flare or candle).
3.1.26 MPU response pressure ( RSrab.) - pressure at which the membrane should collapse (rupture). Indicated together with the response temperature.
3.1.27 Maximum spring deflection- spring compression, at which the gap between the middle coils of the spring does not exceed 0.1 of the diameter of the rod.
3.1.28 Designated membrane service life- calendar duration of operation, upon reaching which the membrane should be replaced, regardless of its technical condition.
4 General provisions
4.1 At each enterprise or production facility, if it is isolated, instructions for the operation, inspection and repair of spring safety valves and MPUs are developed and approved by the chief engineer (technical director).
4.2 Installation of safety valves on vessels, apparatus and pipelines operating under overpressure, is produced in accordance with current regulatory documents and safety rules. The number, design, installation location of valves, MPU and direction of discharge are determined by the project.
4.3 Safety valves and MPU are supplied by manufacturers with a passport and instructions (manual) for use. The passport, along with other information, indicates the service life, valve flow coefficient for compressible and incompressible media, as well as the area to which it is assigned. The manufacturer must have permission to use.
4.4 The diameter of the fitting for the safety valve is taken to be no less than the diameter of the valve inlet pipe.
4.5 The diameter of the valve outlet pipe is taken to be no less than the diameter of the valve outlet fitting.
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 of the total cross-sectional area of the valves installed on it.
In the case of combining the outlet pipes of valves installed on several devices, the diameter of the common manifold is calculated based on the maximum possible simultaneous discharge of the valves, determined by the project.
4.6 The riser diverting the discharge from the safety valve into the atmosphere is protected from precipitation and a drainage hole with a diameter of 20 - 50 mm is made at the lowest point to drain the liquid.
The direction of discharge and the height of the outlet riser are determined by the design and safety rules.
4.7 Sampling of the working medium from branch pipes and sections of connecting pipelines from the vessel to the valve on which safety valves are installed is not allowed.
4.8 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 a throughput in accordance with the requirements of the “Rules for the Design and Safe Operation of Pressure Vessels”.
When installing a group of safety devices and fittings in front of (behind) them, the blocking must be performed in such a way that in case of any valve shutdown option provided for by the design, the remaining switched on safety devices have a total capacity in accordance with the requirements of the “Rules for the Construction and Safe Operation of Pressure Vessels” "
4.9 Heating, cooling, separation and neutralization devices can be installed after the valve. The total reset resistance should not exceed that specified in paragraph.
List of set pressures, frequency of checks and revisions in the form given in the appendix;
Schedule of inspection and repair in the form given in the appendix;
Operational passports in the form given in the appendix;
Passports for MPUs, membranes and springs from manufacturers (stored together with operational passports for valves);
Calculations of the capacity of safety valves (see Appendix) are included in the corresponding passports of vessels (devices), pipelines, pumps, compressors on which the valves are installed.
The following technical documentation is additionally prepared at the LPA:
MPU operation log;
Acts of monitoring the integrity of the safety membrane (free form).
Operating data should be regularly recorded in the membrane operation log:
5.8 In case of absence or loss of the manufacturer’s passport for a valve or spring, it is allowed to draw up new passports (according to the manufacturer’s form) signed by the chief engineer, chief mechanic of the enterprise, senior mechanic of the workshop, foreman of the specialized workshop, section, workshop that carried out the hydraulic test, technical supervision representative. To draw up a passport, the valve must be disassembled, inspected, a hydraulic test and a spring test have been carried out on the valve, and, if necessary, it must be adjusted. Data on the technical characteristics of the safety valve and spring are filled in based on their factory markings, compliance of the geometric dimensions with the drawings, manufacturer's specifications for the springs and test results.
In case of absence or loss of the manufacturer’s passport for the MPU or a batch of safety membranes (MP), it is allowed to draw up new passports (according to the manufacturer’s form) signed by the chief mechanic of the enterprise, the senior mechanic of the workshop, a representative of technical supervision and the chief engineer of the enterprise. To draw up a passport, the MPU must be disassembled and inspected for the absence of visible damage. The data in the passport for the MPU is entered on the basis of the existing markings of safety membranes and fastening devices, for which the MPU is disassembled, inspected for the absence of visible damage, and representatives from the batch of membranes are tested for response pressure. The passport form for LPA is given in the appendix.
5.9 A plate with the following information is securely attached to the body of each valve:
Place of installation (production, workshop number, designation of the apparatus, pipeline according to the technological diagram);
Set pressure Pvcm,
Working pressure in a vessel, apparatus, pipeline R slave.
Membranes for marking are equipped with marking shanks attached to them. The markings on the shanks are applied from the dome side of the membrane using electrographic, impact or other methods that prevent it from being erased during operation. The marking contains the following information:
Name (designation) or trademark of the manufacturer;
Membrane batch number;
Membrane type (MP or MX);
Membrane material;
Nominal diameter Dy (DN) - according to MPU;
Working diameter (Dpab.) - according to that specified in the MPU passport;
Design diameter (Dpacch.) - according to the technical specifications (order) for the MPU;
Minimum and maximum response pressure of membranes in a batch at a given temperature and at a temperature of 20 °C (for all membranes in a given batch).
5.10 Only workers who have passed a knowledge test and are certified in accordance with the current rules are allowed to service safety valves and MPUs. technical devices, where the PC and MPU are installed.
6 Inspection, repair, adjustment and testing of safety valves and MPU. Inspection of clamping tracks
6.1 An inspection of safety valves consists of disassembling, cleaning, troubleshooting parts, testing the inlet part (inlet pipe and nozzle), testing the spring, assembling, adjusting the set pressure, checking the tightness of the valve, testing the valve connections for tightness. The procedure for disassembly and assembly, a list of possible malfunctions in the operation of safety valves and methods for eliminating them are given in the appendix.
Inspection, repair, adjustment, and testing of safety valves are carried out in a specialized repair shop, workshop (site) on special stands in accordance with the instructions for use, inspection and repair of spring safety valves. An approximate list of equipment and mechanisms of a specialized workshop, workshop (site) for inspection and repair of safety valves is given in the Appendix.
6.2 The value of the set pressure, the frequency of inspection, repair and adjustment, the installation location, the direction of discharge from the safety valves are indicated in the list of set pressures (see Appendix). The statement is compiled for each production facility of the enterprise, agreed with the technical supervision service, the chief mechanic and approved by the chief engineer (technical director) of the enterprise and stored at the production facility, in a specialized repair shop, workshop (site), in the technical supervision service.
6.3 For valves that have undergone inspection, repair, adjustment and testing, an inspection report is drawn up (see Appendix) with mandatory verification of the actual set pressure with the list of set pressures.
6.4 Valves that have undergone inspection, repair, adjustment and testing are sealed with a special seal kept by the repairman. The locking screws of the adjusting bushings, the detachable connections between the body and the cover and the cover and the cap are subject to mandatory sealing. The seals indicate the month and year of the inspection and the mark of the specialized workshop, workshop (site). The results of the inspection and repair are recorded in the valve’s operational passport.
6.5 Inspection of the MPU includes disassembly, cleaning and degreasing of parts, and troubleshooting of parts. Parts mating with the membrane that have corrosion or cracking must be replaced.
6.6 Frequency of inspection, repair, adjustment and testing of safety valves
6.6.1 The frequency of inspection, repair and adjustment of safety valves is determined taking into account the conditions and experience of their operation, harmful effects working environment (corrosion, freezing, sticking, polymerization), but it should not exceed the time limits established in - except in cases of using MPU to protect safety valves from corrosion.
The designated service life of the safety membrane is determined by the manufacturer of the MPU, taking into account the specific operating conditions of the safety membrane (corrosion rate of the material, the composition of the working environment of the device being protected, the temperature of the environment at the installation site of the safety membrane, the degree of load (the relationship between the operating pressure and the response pressure of the membrane) and the expected load speed (the rate of increase in the pressure of the “explosion” of the medium in the apparatus) upon activation, the nature of the loading of the membrane during operation (static, alternating, pulsating), the rate of creep of the material under specific operating conditions), and is confirmed by calculation.
6.6.2 The rate of corrosion of valve parts is determined based on safety valve inspection data or testing of samples made of similar steel under operating conditions.
6.6.3 Tests of valve detachable connections for tightness are carried out during each revision.
6.6.4 The timing of inspection, repair, and adjustment of safety valves of a production facility are indicated in an annually compiled schedule in the form given in Appendix B. The schedule is agreed upon with the technical supervision service, the chief mechanic and approved by the chief engineer (technical director).
6.6.5 Valves received from the manufacturer or from reserve storage must be adjusted on a bench to the set pressure immediately before installation on vessels and pipelines. After the expiration of the preservation period specified in the passport, the valve must be subjected to inspection with complete disassembly.
6.7 Defects of safety valve and MPU parts
6.7.1 Valve parts must not have burrs, nicks, dents, or bends. In case of damage to the nozzle and spool (nicks, risks, corrosion), it is necessary machining and subsequent grinding restore their surfaces.
6.7.2 The thread of the adjusting screw must be clean and free of nicks. All fasteners with defective threads are replaced.
6.7.3 Safety valve springs are checked visually for cracks and corrosion pits.
Springs are considered unsuitable for use if dents, nicks, cracks, and transverse risks are found during inspection.
The perpendicularity of the ends of the spring axis must be within the tolerance specified in the appendix, in the tables and.
6.7.4 During each inspection of the safety valve, the springs are subjected to control, including:
Threefold compression by a static load causing maximum deflection, while the spring should not have a residual deformation (shrinkage) of more than 1.5% of the original height of the spring in a free state;
Compression of the maximum working static load specified in the passport or specification for the springs, the axial movement must be within the limits specified in the appendix, in the tables and;
Checking for the absence of surface cracks using magnetic particle or capillary flaw detection; the need for inspection is determined by the instructions of the enterprise operating the safety valve.
In addition to magnetic particle or penetrant flaw detection, springs can be checked for surface cracks by immersing the spring for 30 minutes. in kerosene and then wipe it dry, after which the spring is sprinkled with chalk powder. Dark streaks on the surface of the chalk indicate the presence of surface cracks; such a spring is rejected.
Magnetic particle and penetrant flaw detection are carried out in accordance with RDI 38.18.017-94 and RDI 38.18.019-95.
6.7.5 If traces of corrosion or wear are visually detected on the valve body, it is subjected to thickness testing. Rejection of the housing according to wall thickness, as well as the sealing surfaces of the flanges, is carried out in accordance with clause 13.52 RD 38.13.004-86.
6.7.6 When inspecting the MPU or replacing the membrane and detecting corrosion damage or cracking of the surfaces of the clamping rings mating with the membrane, the clamping rings must be replaced.
Fasteners (studs, nuts) are rejected if they are worn out, threads are chipped, or turnkey surfaces are worn out.
6.8 Adjusting safety valves
6.8.1 Adjustment of safety valves to the set pressure is carried out on a special stand. The installation pressure is determined by the project in accordance with the “Rules for the Design and Safe Operation of Pressure Vessels”.
Rice. 3. Installation diagram of the MPU with a three-way valve in front of the valves.
7.4 MPU should be installed on branch pipes or pipelines directly connected to the vessel.
7.5. The connecting pipelines of the MPU should be protected from freezing of the working environment in them.
7.6. MPU should be placed in places that are open and accessible for inspection, maintenance, installation and dismantling.
List of organizations specialized in the design and manufacture of membrane safety devices.
