All newly installed fittings at main pipeline facilities must have:

certificates of conformity certifying its compliance with the requirements of State standards and regulatory documents of Russia;
permission from Rostekhnadzor for the right to produce and use these products.

During operation, valve maintenance is performed.

Valves.

The technological operating mode of the valves, indicating the type of control (local or remote), the pressure drop across them and the maximum operating pressure are established on the basis of design documentation.

Operation of valves with a half-closed shutter is prohibited. The exception is emergency situations at the oil pumping station, when valves can be used for a short time to throttle the pressure.

The staff on duty conducts technical inspections once per shift. shut-off valves, during which the following are checked:

tightness of flange connections and gland seals;
smooth movement of moving parts;
serviceability of the electric drive.

Within maintenance The following work is performed once a month:

minor repairs of valves that do not require a special stop of main pumps (cleaning external surfaces, eliminating oil leaks, maintaining sites, etc.);
visual check of the condition of all parts of the valves;
checking the presence of lubricant in the electric drive gearbox and replenishing it;
checking the tightness of the stuffing box and flange connections;
checking the functionality of the electric drive (terminal fastening, overload protection, operation of limit switches and torque limiting clutch);
control of seal tightness.

To ensure the tightness of flange connections, they are tightened twice a year (in spring and autumn). The same procedure is followed if a leak is detected in flange connection.

Tightening of valve flange connections must be carried out at a pressure reduced to a safe level. It must be borne in mind that before tightening the flange connection of the body and the cover of the wedge valve, it is necessary to open the wedge slightly to avoid damage to the threaded bushing.

Determination of the torque of the electric drive of the valve is carried out by measuring the current strength of its electric motor. Its value should not exceed the nominal value by more than 10%.

When carrying out seasonal maintenance, once every 6 months the valve seal is checked for tightness. It is combined with planned stops of the main pipeline and oil pumping station.

To control the tightness of the valve, a pressure difference equal to 0.1-0.2 MPa is created with an excess pressure of at least 0.4 MPa. The criteria for assessing tightness are the change in pressure in the cut-off sections of the pipeline and the presence of noise of leakage of the pumped liquid through the valve.

The change in pressure in the cut-off section of the pipeline is monitored according to the readings of pressure gauges (not lower than the first class of accuracy with a division value of no more than 0.05 MPa) in no less than 30 minutes. The valve is considered not airtight if the pressure change in half an hour is 0.1 MPa or more.

The noise of leakage of the pumped liquid through the valve is recorded using acoustic devices (leak detectors, sound level meters). The detection of such noise in the valves of the pump connection unit to the main pipeline, the discharge and suction lines of the main pumps (aggregate valves), the SOD start-up and reception chamber, and the inlet-dispensing pipes of the tanks indicates that the valve is leaking. In other cases, leaks should not exceed the permissible value determined by the tightness class of the valves.

The criteria for their inoperability are:

Leaks through gland seals and flange connections that cannot be eliminated by additional tightening;
leakage of the pumped medium in the valve exceeding the permissible value;
jamming of the moving parts of the valves when opening and closing the valves;
increase in response time beyond the permissible limit;
failure of the electric drive.

Inoperative valves are repaired.

Information on ways to eliminate their possible malfunctions is given in the table below.

Possible malfunctions of valves and ways to eliminate them

Malfunction	Possible reasons	Remedies
Medium leakage when valve is closed	You break the seal due to wear or contamination of the surfaces of the sealing rings of the body and the wedge or disk. Insufficient force on the flywheel (less than calculated). Insufficient torque developed by the electric drive. Formation of sediment particulate matter or resins in the lower part of the body	Disassemble the valve, clean, grind or replace the sealing rings. Increase the force on the flywheel to the calculated value. Check the torque clutch setting. Check the voltage at the input. Check the technical condition of the electric motor.
Passing the medium through the housing-lid connection	Loss of tightness due to insufficient tightening of bolts. The gasket is damaged. The sealing surfaces of the housing or cover are damaged	Tighten the bolts evenly. Replace the gasket. Remove the cover, repair the damage and rub the sealing surfaces
Passing the medium through the stuffing box	The stuffing box packing is not tight enough. Wear of the stuffing box. Spindle surface damaged	Tighten the oil seal nuts evenly. Refill the oil seal or replace the packing. Repair spindle surface damage
Moving the shutter with delays or with increased torque	The wedge or disc guides are damaged. Formation of solid particles or resin on the guides	Disassemble the valve and repair the damage. Disassemble the valve and remove sediment
Increased torque on the flywheel required for closing	There is no lubrication in the moving joints	Lubricate the moving joints
The electric drive does not work	No power to the electric drive	Check and correct the power line of the electric drive

Pressure regulators. During maintenance of pressure regulators, which is performed by maintenance personnel once a month, the following work is performed:

external inspection to check the tightness of the housing and connections;
checking the tightness of the stuffing box seals and, if necessary, tightening them;
monitoring the integrity and serviceability of the shaft, drive levers, and gearbox;
checking the presence of lubricant in the electric drive and gearbox (replenish if necessary);
checking and tightening contact connections of the electric drive.

For the pressure regulator block as a whole the following are produced:

control of the accuracy and synchronism of the shutter actuation;
checking the functioning of the block heating system.

Safety valves.

The integrity of the safety valve body may be compromised due to corrosion, fatigue, or increased permissible pressure.

Due to damage to the sealing surfaces or foreign objects on them, misalignment of valve parts and other reasons, it is possible for the pumped liquid to pass through the valve seal at a pressure less than the calculated one.

Due to the excessively high flow rate of the discharged liquid, as well as deposits on the surface of the supply pipeline or pipe, pulsation may occur - rapid and frequent closing and opening of the safety valve.

Finally, safety valve may simply not operate at a given set pressure due to an incorrectly adjusted or too stiff spring, as well as increased friction in the spool guides.

Therefore, the scope of maintenance of safety valves includes:

external inspection to determine the integrity of the body;
checking valve operation at a given pressure;
control of tightness and pulsations.

Maintenance of safety valves is performed by maintenance personnel 2 times per shift.

Check valves.

Similar to gate valves, maintenance of check valves is performed by maintenance personnel once per shift and includes:

checking the tightness of seals (with elimination of detected leaks);
monitoring the performance of damping devices and their restoration;
cleaning the outer surface.

The tightness of check valves is checked once a year, similar to gate valves. It should correspond to the values given in the table below.

Check valve tightness standards

Electric drives.

Reliable operation of the electric drive is ensured by:

maintaining its components and parts in working order;
careful fastening of the drive to the valve, electric motor to the gearbox, limit switch to the drive;
timely operation of limit switches and torque limiting clutches;
high-quality lubrication of its rubbing parts.

Therefore, during maintenance of the electric drive, a visual check is made of the condition of the electric drive and supply cables, the condition and fastening of the electric motor terminals, checking the protection of the electric motor from overloads, checking the operation of the limit switches and their revision, checking the operation of the torque limiting clutch, and also checking the presence of lubricant in the bearings and gearbox and replenishing it.

The main malfunctions of electric drives and methods for eliminating them are given in the table below.

Possible malfunctions of electric drives and ways to eliminate them

Manifestation of malfunction	Possible reasons	Remedies
*Manual control*
When the drive is switched to manual control, the flywheel rotates idle	Clutch cams do not engage; clutch cams are broken; the head of the rod or rod has burst; the key on the worm spline shaft or on the flywheel is torn off	Remove the manual control unit, check the clutches and gears
When switching the drive from electric and back, the rod does not move or moves slowly	The pins touch the walls of the worm grooves; jamming of the rod or rod in the guides; spring is broken. Jamming of jaw couplings on the worm shaft	Remove and inspect the manual control and locking assembly, check the condition of the pins and springs. Check the condition of the worm claw couplings and the keys on it
The force on the flywheel increases so much that it is impossible to open or close the valve	Jamming of moving parts of valves or electric drives	Rotate the handwheel in the opposite direction to repeat closing or opening. If the jam does not clear, find out the cause and fix the problem.
The indicator arrow does not rotate during the stroke	Faulty transmission from the drive shaft to the camshaft of the limit switch. The screw that locks the disk with the arrow is loose	Check transmission. Open the pointer, remove the glass and tighten the locking screw
*Electrical control*
When you click on trigger buttons the electric motor does not rotate	The power circuit is faulty. The starter does not work. No voltage on control panel	Check the power circuit. Check the starter for serviceability. Check starting equipment
When you press the start buttons, the engine rotates idle and the electric drive stops	The electric drive is not switched to electric control. The key on the worm or motor shaft has been cut. The locking screw has loosened and the coupling on the motor shaft has moved towards the bearing	Convert the electric drive to electric control. Disassemble the drive, find out the fault and fix it. Remove the electric motor, put the coupling in place and secure it with a screw.
In the extreme positions of the valve shut-off element, the warning lamps do not light up	The lamps have burned out. There is no tension. The electric drive is stopped in the intermediate position of the shut-off element	Replace lamps. Check control circuit. Check the position of the shut-off element using the local indicator and start the drive by pressing the corresponding button
The “Closed” and “Open” lamps light up at the same time	Short circuit between the wires going to the limit switch	Disconnect the signal wires from the limit switch and eliminate the short circuit
During the movement of the electric drive in the closing direction, the LM lamp came on and the electric motor turned off	Jamming of moving parts of the valve or actuator	Find out the cause of the jamming and eliminate it
When starting an electric drive with bilateral torque limitation from the fully closed position to the opening direction, the valve passage does not open and the LM lamp lights up	Insufficient torque in the opening direction, the torque limiting clutch is activated	Press the clutch spring towards opening
When the “Closed” position is reached, the electric motor does not automatically turn off	The closing cam is loose. Malfunction of the torque limiting clutch release mechanism	Check the settings of the cams and the serviceability of the microswitches and, if necessary, replace the faulty one. Adjust the clutch, check the serviceability and, if necessary, replace the microswitch
When the “Open” position is reached, the electric motor does not automatically switch off	The opening cam is loose. Microswitch is faulty	Check the setting and make adjustments in the “Open” position. Check and, if necessary, replace the microswitch
Inadmissible leakage of medium between the sealing surfaces of the fittings	Insufficient torque. Solid particles have gotten between the sealing surfaces of the fittings. The sealing surfaces of the fittings are worn out or damaged	Press the clutch spring. Clean the passage and sealing surfaces of the fittings. Repair sealing surfaces

During the operation of pipelines, one of the main responsibilities of maintenance personnel is constant and careful monitoring of the condition of the outer surface of pipelines and their parts (welds, flange connections, including fastening pipeline fittings), anti-corrosion protection and insulation, drainage devices, compensators, supporting structures, etc. .d.

The main method of monitoring the reliable and safe operation of process pipelines is periodic inspection, which is carried out by the technical supervision service together with mechanics, supervisors and installations (productions).

The results of the audit serve as the basis for assessing the condition of the pipeline and the possibility of its further operation. As a rule, an inspection of pipelines should be timed to coincide with scheduled preventative repairs of pipeline fittings, individual units, installations or workshops. The timing of inspection of pipelines at pressures up to 10 MPa (100 kgf/cm 2) is established by the administration of the enterprise depending on the rate of corrosion-erosive wear of pipelines, operating experience, results of the previous external inspection, audit. The timing should ensure safe, trouble-free operation of the pipeline in the period between inspections.

For high-pressure pipelines [over 10 MPa (100 kgf/cm2)], the following types of inspection are established:

selective, general selective and complete. The timing of the selective audit is set by the enterprise administration depending on the operating conditions, but at least once every 4 years.

The fittings of technological pipelines are the most critical element of communications, therefore the necessary measures must be taken to organize constant and thorough supervision of the serviceability of the fittings, as well as timely, high-quality inspection and repair.

Inspection and repair of pipeline fittings, including check valves, as well as valve drive devices (electric, pneumatic, hydraulic, mechanical drive), are usually carried out during the pipeline inspection period. Inspection and repair of fittings should be carried out in specialized workshops or repair areas. In some cases, at the discretion of technical supervision, it is allowed to inspect the fittings by disassembling them and inspecting them directly at the installation site (welded fittings, large-sized, hard-to-reach, etc.). When inspecting valves, the following work must be performed:

a) external inspection;

b) disassembly and inspection of the condition of individual parts;

c) inspection inner surface and, if necessary, testing by non-destructive methods;

d) grinding in of sealing surfaces;

e) assembly, testing and crimping for strength and density.

When planning the inspection and repair of fittings, one should first of all carry out the inspection and repair of fittings operating in the most difficult conditions, while observing the principle of alternation. The results of repairs and testing of fittings are documented in a report.

The need for valve maintenance is its main disadvantage, but the possibility of repair is one of the main advantages.

Possible malfunctions and methods for eliminating them

Malfunction		Elimination
Leaky flow shut-off	Defects in the contacting surfaces of the valve and body. (scale, shells, scratches)	Grinding in of sealing surfaces on the valve and in the body. As a rule, the contacting surfaces are made of bronze. To do this, it is necessary to dismantle the cover, remove the shutter, and, if necessary, the body. Grinding is performed with diamond pastes of various grain sizes with a gradual transition from coarse to fine. It should be borne in mind that in wedge valves, after several grindings, the valve subsides, which leads to a violation of the tightness even with ground wedge surfaces.
Leakage from under the oil seal along the rod	The rod is not sealed	Tighten the seals and, if necessary, replace the seal packing. If after replacing the seal the leak could not be eliminated, most likely corrosion pits have formed in the rod and it will have to be welded or replaced.
The flywheel cannot be turned	The shutter is jammed	Occurs in valves that lack attention from maintenance personnel and are opened less than once a year. The reason is scale on the sealing surfaces. Remove the top cover of the valve and clean the sealing surfaces of the disc and body. If necessary, grind in rubbing surfaces. It is not allowed to knock on the rod, as the guide nut may be torn off.
The flywheel rotates, but the valve does not open	Shutter breakage "cheeks fell"	In valves with a rising stem, this problem appears when the “cam” of the rod holding the valve is worn out or if the thread on the rod guide nut has been torn off. If there is a problem with the rod, it should be replaced or the worn out “cam” welded on. A worn guide nut should be replaced if the valve design allows it. In valves with a non-rising stem, the valve may fall if the nut fixed in it wears out. To eliminate the malfunction, it is necessary to replace the valve, since it will most likely not be possible to replace a nut with a broken thread.

It is prohibited to disassemble a valve under pressure.

After installation, it is necessary to remove air from the valve; to do this, loosen the bolts pressing the oil seal, and after drops of water appear from under the oil seal, the bolts are pressed.

Once a month, perform a full cycle, open/close, to clean the rubbing surfaces from a small layer of accumulated scale or sludge.

Keep the stem of valves with a rising stem lubricated.

Once a week, check the tightness of the stem seal and, if necessary, tighten or replace it. It is not allowed to replace the seal on a pipeline under pressure.

The gate valve should not be in an intermediate position during operation. Either a fully open or fully closed shutter position is allowed.

The invention is intended for repairing shut-off pipeline valves. A method for repairing gate valves, mainly wedge valves, by installing, with a gap, finally processed seats in the body bores on an adhesive self-curing composition, followed by assembly and curing of the assembled adhesive composition. Before assembly, threads are cut in the body bores and on the seats. Each seat is made with an annular radial protrusion. After this, the seats are screwed onto the adhesive self-curing composition into the threaded bores of the body. In this case, an elastically deformable element is installed between the annular radial projections of the seats or the ends of the seats and the body. This allows the screw-in seat to self-align along the wedge, and one elastically deformable element ensures that all gaps are removed, which increases the tightness of the connection between the seats and the body. This implementation reduces labor intensity and increases the reliability of valve repair. 3 ill.

The invention relates to the mechanical engineering industry, in particular to the repair of pipeline fittings. There is a known method of restoring the sealing fields of the valve, which consists in surfacing a hard stainless alloy directly onto the body and wedge of the valve, followed by machining and lapping (see A.F. Pongilsky. Mechanic for repairing pipelines and steam-water valves. M.: graduate School , 1973). This method is quite labor-intensive and requires special, precise and complex equipment. There is also a known method for repairing wedge valves (see AS 310078), which consists of installing, for example, final processed metal rings on a self-hardening composition in the gap in the bored grooves of the body and wedge, followed by assembling the wedge and body, holding the assembly until the composition is cured . The disadvantages of this method include the possibility of incomplete contact of the sealing rings of the housing and the wedge with each other (and therefore lack of tightness) and the impossibility of self-installation in the absence of a lateral gap between the ring and the groove. And if these gaps are made sufficient for self-installation of the rings, it is possible that the self-hardening composition is squeezed out before the start of its polymerization, which means there is no elastic compression of the rings to each other, which also leads to loss of tightness or the appearance of incomplete contact of the rings with the adhesive composition, which reduces the reliability of the connection. Moreover, this method is not applicable to valves with screw-in seats (see D.F. Gurevich. Calculation and design of pipeline fittings. Leningrad: Mashinostroenie, 1969, Fig. 129-131). The objective of the invention is to reduce labor intensity and increase the reliability of repairs. The technical result is achieved by the fact that the sealing fields of the wedge and screw-in seats are mechanically processed “as clean”, i.e. with the minimum allowance removed until signs of wear disappear, the sealing fields of both the body seats and the wedge are ground in, the threads are cut on the seats in the body bores, then they are screwed onto an adhesive self-hardening composition into the body threaded bores, between the annular radial protrusions of the seats or an elastically deformable element is installed at the ends of the seats and the body. The essence of the invention is illustrated by drawings: Fig. 1 shows a cross-section of a wedge valve with screw-in seats; Fig. 2 - view A in Fig. 1, option, in Fig. 3 - view A in Fig. 1, option. In the body 1, 2 seats 3 are installed on the thread 2 with a gap 4, in which a self-hardening composition 5 is placed, limited by an elastically deformable element 6 or 7 installed between the body 1 and the annular radial protrusion 8 or the end 9 of the screw seat 3, the sealing field 10 of which interacts with the sealing field 11 of the wedge 12. After disassembling, the seats 3 are cleaned of dirt, the sealing fields are processed “as clean” and ground in, the seat threads and body bores are cut or the existing threads are loosened with a gap sufficient for self-installation, then the sealing fields are also processed “as clean” 11 wedges 12 and grind them in. Then the threads of the seat 3 are covered with a self-hardening composition 5, elastically deformable elements 6 or 7 are installed and the seat 3 is screwed into the body 1, after which the wedge 12 is inserted into the body 1, taking into account the overlap of the sealing fields of the wedge and the seat, ensuring the tightness of the product, and left assembled until self-denial. The valve is ready for operation. Depending on the degree of wear of the sealing fields of the seats 10 and the wedge 11, one or two seats are installed on the elastic element 6. Thus, minimal machining “as clean”, grinding in four fields, cutting threads - this is the volume of machining of the proposed method, which is significantly less than known analogues. Gaps in the mating allow the screw seat to self-align along the wedge, and one elastically deformable element allows you to select all the gaps in the seals.

Formula of invention

A method for repairing gate valves, predominantly wedge valves, by installing, with a gap, finally processed seats in the body bores onto an adhesive self-curing composition, followed by assembly and curing of the adhesive composition assembly, characterized in that before assembly, threads are cut in the body bores and on the seats, with each seat being made with an annular radial protrusion, after which the seats are screwed onto an adhesive self-hardening composition into the threaded bores of the body, while an elastically deformable element is installed between the annular radial protrusions of the seats or the ends of the seats and the body.

Similar patents:

This invention relates to a shut-off valve comprising a housing (1), two o-ring seals (20) located in this body (1), and two gate discs (12) located between these o-ring seals (20), which, with the help of an actuator (7), ) can be brought into contact with both O-rings (20). According to the invention, it is proposed that each gate disc (12) on its side facing the other gate disc (12) be equipped with a recess (28) in which there is a corresponding pressure block (22a, 22b), and each pressure block (22a, 22b) on its facing side on the other side of the pressure block there is a recess (34, 37), while both recesses (34, 37) together form a space (40) in which a package (23) of disc springs is placed, containing several disc springs (41) with a first elastic force and a first stroke of each spring and a plurality of disc springs (42) with a second spring force and a second stroke of each spring, the first spring force being greater than the second spring force and the first spring stroke being less than the second spring stroke. 6 salary f-ly, 4 ill.

The invention relates to the field of mechanical engineering, in particular to a device for a parallel pipeline valve with a sliding spindle, and can be used as equipment for pipelines for various purposes. The valve consists of a body 1 with cheeks 2, a retractable spindle 3, a wedge spacer element 4 attached to it, gate discs 5, a cover 6 with a stuffing box assembly 7. The body 1 has upper stops 8, and the rear beveled surfaces of the gate discs 5 have shaped (in our case, T-shaped) slots. On the side surfaces of the wedge spacer element 4 there are responsive projections to the T-shaped groove. In the lower inner surface of the body 1 there are lower stops 9 to limit the vertical downward movement of the breech disks 5. To create additional force for lifting the wedge spacer element 4 and to prevent premature lifting of the breech disks 5, springs 10 with pushers 11 are placed in the wedge spacer element 4, and on the rear On the surfaces of the valve discs 5, stops 12 are attached for the pushers 11. The invention is aimed at increasing operational reliability due to reduced wear of the seals while simultaneously simplifying the design and increasing its manufacturability. 1 salary f-ly, 3 ill.

The invention relates to the engineering industry, in particular to the repair of pipeline fittings

PUBLIC CORPORATION
JOINT STOCK COMPANY
ON OIL TRANSPORTATION "TRANSNEFT"
JSC AK TRANSNEFT

TECHNOLOGICAL
REGULATIONS

REGULATIONS
MAINTENANCE
AND REPAIR OF SHUT-OFF VALVES

Moscow 2003

The regulations developed and approved by JSC AK Transneft establish industry-wide mandatory requirements for the organization and performance of work in the field of main oil pipeline transport, as well as mandatory requirements for the registration of the results of this work.

Regulations (enterprise standards) are developed in the system of JSC AK Transneft to ensure reliability, industrial and environmental safety of main oil pipelines, regulation and establishment of uniformity of interaction between the divisions of the Company and JSC MN when carrying out work on the main production activities both among themselves and with contractors , government supervisory authorities, as well as unification of the application and mandatory implementation of the requirements of relevant federal and industry standards, rules and other regulatory documents.

REGULATIONS
MAINTENANCE
AND REPAIR SHUT-OFF VALVES

1. GENERAL PROVISIONS

This regulation establishes a list and procedure for performing basic operations for the maintenance and repair of shut-off valves at oil trunk pipeline facilities.

The purpose of developing this regulation is to establish an assessment procedure technical condition, the procedure for maintenance and repair of shut-off valves.

The regulations establish:

Criteria for the technical condition of shut-off valves;

The procedure for carrying out diagnostic control;

Typical scope of work on maintenance and repair of shut-off valves;

Maintenance and repair standards.

2. equipment range

The regulations on maintenance and repair apply to shut-off valves of main oil pipelines with a nominal diameter of up to 1200 mm.

3. MONITORING THE PERFORMANCE OF FITTINGS

3.1. All domestic and imported valves newly installed at main oil pipeline facilities must have certificates of conformity certifying the compliance of the shut-off valves with the requirements of State standards and regulatory documents of Russia and permission from the State Technical Supervision Authority of Russia for the right to produce and use these products.

The RNU (JSC) must take into account the service life, operating time and number of closed-open operating cycles of the valves.

3.2. The fittings are considered operational if:

The strength of the materials of parts and welds operating under pressure is ensured;

There is no leakage of medium and sweating through metal and welds;

The tightness of the stuffing box seals and flange connections of the fittings is ensured in relation to external environment;

The tightness of the valve valve is ensured in accordance with the passport for the shut-off valve;

Ensures smooth movement of all moving parts of the fittings without jerking or jamming;

The electric drive ensures smooth movement of the shutter, opening and closing within the time specified in the passport; the electric drive is switched off when the valve reaches its extreme positions and when the torque exceeds the permissible value on the yoke assembly.

If any of these conditions are not met, the valve is considered inoperable and is taken out of service.

The performance of the fittings is characterized by reliability indicators. Reliability indicators include: the assigned service life of the valve, the assigned resource - in “open-closed” cycles, the assigned service life before repair, the probability of failure-free operation during the assigned resource.

3.3. The inoperability of the reinforcement is determined by the criteria of failures and limit states.

The failure criteria for shut-off valves are:

· loss of tightness in relation to the external environment that cannot be eliminated by additional tightening;

· leakage of medium in the gate beyond the permissible limit;

· impossibility of working movements of the shut-off element (jamming of moving parts) when opening and closing the valve;

· increase in response time beyond the permissible limit;

· failure of the electric drive.

The criteria for limit states of reinforcement are:

· achieving the designated service life;

· destruction or loss of density of the base material and welds;

· violation of the geometric dimensions of mating parts (due to wear or corrosion destruction).

Upon reaching the designated service life, the shut-off valves are subject to re-examination in order to determine its technical condition and the possibility of extending its service life.

Reliability indicators, failure criteria and limit states are indicated in the valve certificates.

3.4. Monitoring of the performance and technical condition of the valves is carried out by external inspection, diagnostics and testing

3.4.1. During an external inspection the following is checked:

· condition and density of materials and reinforcement welds;

· smooth movement of all moving parts of the valves and electric drive;

· serviceability of the electric drive;

· tightness of the fittings in relation to the external environment, including:

· tightness of gasket seals;

· tightness of the stuffing box seal.

When the shut-off valve is in working order, the passage of medium through the stuffing box and gasket seals is not allowed.

3.4.2. The technical condition of the valve during operation should be determined by diagnostic monitoring. To determine the technical condition of the valve body and welds, acoustic emission (AE), ultrasonic (UT) and other non-destructive testing methods are used.

Carrying out diagnostic monitoring of the valve is combined in terms of timing with major repairs (table), and is also carried out when excessive stresses are detected on the nozzles or when failures occur in the operation of the valve according to the criteria of limit states. When diagnosing, devices and AE sensors and ultrasonic testing devices or flaw detectors are used.

Diagnostic control and conclusions based on its results are carried out by specialized organizations that have permission from the State Mining and Technical Supervision of Russia, or by specialists from the Russian National Research University, Central Bureau of Technical Inspection, if they have a developed and approved diagnostic control methodology.

The results of diagnostic testing (conclusion) are entered into the valve form or attached to its passport.

Monitoring the tightness of the valve valve during operation can be carried out using acoustic emission leak detectors.

3.4.3. On existing main oil pipelines, the fittings are also tested for strength and density of materials and welds, tightness with respect to the external environment, valve tightness and performance. Testing of fittings is combined in terms of testing of oil pipelines or is carried out after major repairs of oil pipelines.

The test mode and test pressures are established and depend on the life and operating parameters of oil pipelines in accordance with regulatory documents regulating testing on existing oil pipelines.

4. TYPICAL SCOPE OF MAINTENANCE WORK

The scope of maintenance includes the following work:

Minor repairs to valves that do not require a special stop of main pumps (cleaning external surfaces, maintenance of sites, eliminating oil leaks, etc.);

Visual check of the condition of all parts of the shut-off valves, including lubricants in bearings and gearboxes, and their replenishment;

Checking the condition and fastening of the electric motor terminals, checking the protection of the electric motor from overloads and phase imbalance;

Checking the operation of limit switches, their revision;

Checking the operation of the torque limiting clutch;

Checking the tightness of the stuffing box and flange connections.

The oil seal repair operation is carried out in accordance with the manufacturer's operating instructions.

To ensure the tightness of the flange connections of the shut-off valves, it is necessary to tighten the flange connections twice a year (in spring and autumn); if a leak is detected in the flange connection, the bolts and nuts are uniformly tightened; if moderate tightness of the flanges does not give positive results and the leak continues, the gasket is replaced according to the manufacturer's operating instructions.

Before tightening the flange connection (body and cover) of wedge valves, it is necessary to open the wedge slightly to avoid damage to the threaded bushing.

Tightening of flange connections of shut-off valves must be carried out at a pressure reduced to a safe level in the oil pipeline or in a disconnected section of the oil pipeline.

The scope of maintenance of the check valve includes the following work:

Checking the tightness of seals, eliminating detected leaks;

Checking the performance of damping devices (shock absorbers) and their restoration.

5. TYPICAL SCOPE OF WORK DURING ROUTINE REPAIRS

During routine repairs, all maintenance operations are performed, as well as:

for wedge or gate valves - removing air from the valve: preparing the necessary repair devices, transport and lifting mechanisms; removing the gearbox with an electric drive, disassembling the gearbox and electric drive, cleaning and washing parts, defect detection, replacing worn parts, lubricating the gearbox and the mechanical part of the electric drive, assembling them; checking and tightening the contact connections of the electric drive, restoring the insulation of the output ends of the wires, checking the condition of the explosion protection seals of the ball bearings of the electric motor, the correct fit of the electric motor fan impeller, replacing defective parts of the electric motor; checking the condition of the bearing assembly of the valve stem after its fixation, determining the degree of wear of the threaded bushing of the stem (in case of excessive wear, replace it): eliminating traces of corrosion of the stem, scoring; replacing oil seals and pressure bushings, if necessary; running the spindle along the nut to its entire working length; tightening the studs of the housing connector, complete assembly and installation of the electric drive on the valve; adjustment of limit switches for opening and closing, torque limiting clutches for shutdown according to permissible values.

Current repairs of shut-off valves are carried out without dismantling them.

Data on the performed maintenance and current repairs are entered into the preventive inspection and repair log by the person responsible for the good condition of the facility. The log is kept by the person responsible for the good condition of the object. The form for the preventive inspection and repair log is given in the Appendix.

6. TYPICAL SCOPE OF WORK DURING A MAJOR REPAIR

Major renovation shut-off valves are carried out with its dismantling. Dismantling of gate valves and check valves subject to major repairs is carried out according to a schedule approved by the clay engineer of RNU (JSC MN). Major repairs of valves are carried out by the Central Bureau of Industrial Engineering or a specialized organization in accordance with specifications and working drawings approved in the prescribed manner.

During a major overhaul, all operations are performed current repairs, as well as: complete disassembly and defect detection of all parts and assemblies, their restoration or replacement of those that have become unusable as a result of corrosion, excessive mechanical wear of assemblies and basic parts of shut-off valves.

After a major overhaul, the valves are tested for strength and density of materials and welds, tightness in relation to the external environment, valve tightness and performance in accordance with the requirements of E and regulatory and technical documentation for major overhauls of shut-off valves.

Testing the strength and density of the valve assembly material is carried out with the valve open and pressure pipes pluggedP pr ( P pr = 1,5 P N, Where P N - nominal pressure). Strength and density tests are carried out at constant pressure for the time required to inspect the valve. The passage of medium and sweating through metal and welds is not allowed.

Testing of fittings for tightness in relation to the external environment is carried out at a pressure of 1.1P N for the time necessary to inspect the seal and connections. The tightness of the upper cover-spindle seal is checked with the gland seal fastenings loosened and the valve spindle fully raised. The tightness of the stuffing box and the gasket between the cover and the body is checked. Leaks of the medium are not allowed. The control method is visual.

Testing of valve fittings for tightness is carried out in accordance with Table. and requirements.

Table 1

Valve leak test

Nominal size (nominal diameter) D N , mm	Nominal pressureP N , MPa (kgf/cm 2)	Valve leak test parameters
D N £ 80	P N ³ 0,1 (1)	water - pressure 1.1P N or air
D N ³ 100 D N £ 200	P N £ 5,1 (50)	pressure 0.6 ± 0.05 MPa
D N ³ 100 D N £ 200	P N ³ 6,3 (63)	water - pressure 1.1P N
D N ³ 250	P N ³ 0,1 (1)	water - pressure 1.1P N

Tests for tightness of the valve are carried out after closing the valve body in the manner provided for in technical conditions for a specific type of fittings.

The minimum duration of the valve tightness test is given in Table. .

The maximum permissible leakage values in the valve according to tightness classes are indicated in table. .

Table 2

Minimum duration of valve leak testing

Nominal size, D N, mm	Minimum test duration, s
Nominal size, D N, mm	Metal to metal seal	Non-metallic seal
D N£ 50
65 £ D N£ 200
250 £ D N£ 400
500 £ D N	120

Table 3

Minimum permissible valve leakage under various test environments

Test Environment	Leakage class
Test Environment
Leak rate when tested with water (cm 3 /min)	No visible leaks	0,0006 × D N	0,0018 × D N	0,006 × D N
Outflow value during testingair(cm 3 /min)	No expiration	0,0018 × D N	0,18 × D N	1,8 × D N

Notes

1. When determining leaks, the nominal diameter DN, is taken in millimeters.

2. The leakage values correspond to the case of leakage into the atmosphere.

3. The tightness class for shut-off valves is indicated in the technical specifications and the passport for a specific type of valve.

4. The test medium is selected depending on the purpose of the fittings in accordance with the requirements.

5. Temperature of the test environment - from 5 to 40 ºС.

6. The error in leakage measurements should not exceed:

± 0.01 cm 3 /min - for leaks 0.1 cm 3 /min;

± 0.5 cm 3 /min - for leaks > 0.1 cm 3 /min.

7. Leaks are collected with a syringe and measured leaks- beaker E with a division value of 0.1 cm 3.

The performance test of the valve is carried out by turning on the electric drive for three complete “open-close” cycles.

Moving parts must move without jerking, jamming or jamming. The manual control of the valve is checked by rotating the steering wheel in both directions.

In the closed state, the valve is subject to a pressure difference, the value of which is set according to the manufacturer’s operating instructions. The smooth movement of the valve gate is also checked, the operation of the electric drive is checked, the limit switches are set to turn off the electric motor when the shut-off element of the valve reaches the extreme positions, the torque switches are set to turn off the electric motor when the electric drive of the valve reaches the maximum torque value when the shut-off element or moving parts of the valve are stuck, At the same time, the operating time and current value of the electric drive are controlled, which must be within the rated values.

During normal operation of the shut-off and control valve, the torque Mcr should not deviate from the nominal value by more than 10%.

The value of Mcr is determined by measuring the value of the electric drive current.

Data on the major repairs carried out are entered into a form that is attached to the repaired fittings. The form is issued by the organization that repaired the valves and is filled out by the engineer responsible for the quality of the products. The form must be kept together with the passport for the shut-off valves by the person responsible for the good condition of the facility. The form of the form is given in the appendix.

7. MAINTENANCE AND REPAIR STANDARDS

For pipeline valves of the oil pumping station, the turnaround cycle and types of repairs are established taking into account reliability indicators, service life and operating time of open-close cycles, the results of diagnostic inspections and tests (clause 4.4.2, clause 4.4.4), assessment of the technical condition of the valves during previous repairs or maintenance.

The frequency of maintenance and repair, labor intensity standards for maintenance and current repairs are determined by the typical scope of work, type and size of fittings and are given in.

Data on the frequency of maintenance and repairs, labor intensity standards for maintenance and routine repairsare presented in table. And .

Table 4

Frequency of maintenance and repair of valves

Equipment name	Periodicity
	TO, months		Control of valve tightness, years/cycles	T, months	K, years (cycles)
	Inspections, cleaning, lubrication	Changing the lubricant, packing the oil seal, etc.	Control of valve tightness, years/cycles	T, months	K, years (cycles)
Steel valves: Æ 50 - 350 mm			2/220		10 - 12 (1450)
Æ 350 - 1220 mm onP slavefrom 1.6 to 2.5 MPa			2/250		10 - 12 (1450)
on P slave from 2.5 to 7.5MPa			2/220		8 - 10 (1450)
Check valves			2/-

Note.If the valve data sheet contains reliability indicators for service life before repair and average service life (in cycles), then the frequency of valve repairs is set according to these indicators. The necessary changes in columns 5, 6 are made by the chief specialists of RNU in the PPR schedules and approved by the chief engineer of RNU.

Table 5

Labor intensity standards for maintenance and repair of valves

Equipment name	Labor intensity standards, person-hours
Equipment name	THAT
Valves steel diameter:
50 - 80 mm	0,2	1,2
100 - 150 mm	0,7	1,8
180 - 250 mm	1,0	3,3
300 - 400 mm	1,3	4,8
500 - 700 mm	2,7	8,3
800 mm	4,0	10,0
1000 mm	5,0	12,0
1200 mm	8,0	16,0
Check valves diameter:
50 - 350 mm	0,6
500 - 700 mm	1,4
800 - 1000 mm	2,0

Table 6

Data on the preparation and maintenance of repair documentation

Item no.	Document name	When is it compiled?	Compiled by (filled in)	With whom is it agreed?	Approved by	Where is it stored?
	PPR schedule	2 months before the end of the current year	Mechanical engineer NPC	With the main specialists of RNU (OGM, OGE, OASU)	Chief engineer of RNU	Mechanical engineer NPC
	Log of preventive inspections and repairs	Before commissioning new equipment	NPS Mechanical Engineer			Mechanical engineer NPC
	Valve passport		Manufacturer			Mechanical engineer NPC
	Form for repair fittings	After the repair is completed	Engineer responsible for product quality		Head of TsBPO (RMZ)
	Conclusion (act) of diagnostic control (DC)	After the DC	Engineer who carried out diagnostic control of TsBPO (RMZ)		Head of TsBPO (RMZ)	Together with a passport for shut-off valves from a mechanical engineer. NPC

Maintenance and repair of shut-off valves is carried out according to the PPR schedule, which is developed by engineers of the relevant services of the pumping station, agreed upon by specialists of the technical services of the RNU and approved by the chief engineer of the RNU.

_______________________________________

(cycles, years)

Reason for repair ____________________________________________

Incoming inspection results

valve coming in for repair_________________________________________________________

Information about the repairs performed ________________________________________________

_________________________________________________________________________

(types and brief information about repairs)

Responsible for filling out the form_____________________________________________

MATERIALS OF MAIN PARTS REPLACED

MAINTENANCE ACCOUNTING
(REGULATION WORK)

Date	Type of maintenance	Operating time		Basis (name, number and date of the document)	Position, surname and signature		Note
		after the last renovation	from the beginning of operation		The person who completed the work	Who checked the work