Permissible vibration level lpds. Vibration diagnostics of pumping units. Options. vibration standards. Criteria for vibration control. General requirements for measurements
Installation and piping of pumping units (PU) are made according to the project. Adjustment and testing are carried out in accordance with the requirements of the relevant instructions of manufacturers.
Pumps assembled with motors are installed on the foundations and are aligned with respect to the reference axes, in plan and in height, with the accuracy determined by the project.
Before tying, frames and pumps are securely fixed to the foundation. After connecting the suction and discharge pipelines, the alignment of the pump unit is checked. The alignment accuracy is set by the factory instructions for the mounted pumps, and in the absence of such instructions, the accuracy should be within:
- runout - radial - no more than 0.05 mm;
- axial runout - no more than 0.03 mm.
Alignment is checked manually by turning the pump and motor shafts connected by couplings. Shafts should turn easily, without jamming. The alignment of the shafts of pumps and motors is measured with appropriate tools (indicators, etc.).
Booster and main pumps before installation are subjected to individual hydraulic tests in accordance with the data of the factory instructions. Hydrotesting of inlet and outlet pipes of booster and main pumps and the pumping manifold after installation and repair are carried out in accordance with the design documentation. Test conditions must comply with the requirements of SNiP III-42-80. Testing of intake and outlet pipes and manifold can be carried out together with pumps.
The engineering and technical staff of the LPDS, PS responsible for the operation and start-up of the SE (electrician, instrumentation engineer, mechanic), before the first start-up or start-up of the SE after repair, must personally check the readiness for operation of all auxiliary systems and the implementation of technical and fire safety measures:
- not later than 15 minutes before the start of the main units, make sure that the system is functioning supply and exhaust ventilation in all premises of the PS;
- check the readiness of the electrical circuit, the position of the oil switch (starters), the condition of the instrumentation and automation equipment;
- make sure that auxiliary systems are ready for start-up;
- make sure that the main NS are ready for launch, stop valves according to the technological scheme;
- check the flow of oil into the bearing units, the hydraulic coupling of the pumps and the coolant to the oil coolers (if they are air coolers, then, if necessary, make sure that they are connected);
- check the presence of the necessary air pressure in the air chamber of the connection shaft in the separating wall (or in the motor housing).
During normal operation, these operations are carried out by the personnel on duty (operator, driver, electrician, etc.) in accordance with their job descriptions and instructions for the operation and maintenance of the equipment.
By the beginning of the operation of the pumping station, instructions should be prepared, which should indicate the sequence of operations for starting and stopping auxiliary and main equipment, the procedure for their maintenance and the actions of personnel in emergency situations.
It is forbidden to start the unit:
- without switching on the supply and exhaust ventilation;
- without included oil system;
- when the pump is not filled with liquid;
- in the presence of technological faults;
- in other cases stipulated by the instructions (official, equipment operation, manufacturer's instructions, etc.).
It is forbidden to operate the unit if the tightness of the connections is broken; during the operation of the unit, it is forbidden to tighten threaded connections under pressure, to perform any actions and work that are not provided for by instructions, regulations, etc.
On non-automated substations, an emergency stop of the SE must be carried out in accordance with the instructions by the duty personnel, including:
- when smoke appears from seals, glands in the separation wall;
- in case of significant leakage of oil product on the operating unit (spraying of oil products);
- when a metallic sound or noise appears in the unit;
- with strong vibration;
- when the temperature of the bearing housing is above the limits set by the manufacturer;
- in case of fire or increased gas contamination;
- in all cases that endanger the operating personnel and the safety of equipment operation.
The pressure difference between the air chamber of the shaft and the pump room must be at least 200 Pa. After the SS is stopped (including after it has been placed on standby), the air supply to the air seal chamber does not stop.
Pumps, hydraulic couplings and motors must be equipped with devices that allow monitoring operating parameters or signaling that their permissible limit values are exceeded. The conditions for the installation and use of these devices are given in the respective manufacturer's instructions.
Supply and exhaust systems ventilation of pump rooms (main and booster) and gas control systems in these rooms should operate in automatic mode. In addition to automatic switching on of supply and exhaust ventilation and switching off pumps, manual control of fans should be provided locally; the emergency stop button of the pump house should be located outside the pump house building near the front door.
Pump casings must be earthed, regardless of the earthing of their motors.
The purge and drain cocks of the pumps must be equipped with pipes for draining and discharging the product into the leak collector and further into the leak collection tank located outside the pump house. Discharge of purge and drainage products of pumps into the pump room atmosphere is prohibited.
After an unscheduled shutdown of the SE, it is necessary to find out the reason for the shutdown and do not start this unit until it is eliminated. The personnel on duty must immediately inform the dispatcher of the branch of the operating organization and neighboring substations about the stop of the unit.
The commissioning of a backup main or booster unit in automatic mode is carried out with a fully open intake and closed discharge (pressure) valve or both valves open. In the first case, the opening of the valve at the pump discharge can begin simultaneously with the start of the electric motor or advance the start of the engine by 15–20 s. In accordance with the project, another procedure for launching the standby NS in automatic mode may be provided.
Automatic input of a backup main, booster unit or a unit of one of the auxiliary systems (oil systems, back-up systems for chambers of pressure-free connections, etc.) is carried out after the main one is turned off without a time delay or with a minimum (selective) time delay.
When starting up a station with a serial piping scheme, it is recommended to start the main pumps against the movement of the oil product flow, that is, starting from a larger unit number towards a smaller one. In the case of launching only one PU, it is possible to launch any of the ready-to-work ones.
The HA is considered to be a standby if it is serviceable and ready for operation. All valves, gate valves on the piping system of the scientific equipment contained in the reserve (cold) must be in the position provided for by the project and operating instructions.
The AS is considered to be in hot standby if it can be put into operation as soon as necessary without preparation or in the ATS mode.
The control over the operation of the PS is carried out by the operator using the instruments installed on the automation board or by the values of the parameters on the monitor screen. During normal operation of the equipment, the controlled parameters of the ND, in accordance with the established list, must be recorded in a special log every two hours. If the equipment parameters deviate from the specified limits, the faulty unit is stopped and the backup unit is started. The operator on duty in this case must record in the operational log the value of the parameter, due to which the operating unit was turned off. Automatic registration of the corresponding parameter is carried out immediately by a special emergency recorder with the issuance of its value and name on the monitor screen.
During the operation of the equipment, it is necessary to monitor its parameters in accordance with the instructions, in particular:
- for the tightness of the equipment piping (flanged and threaded connections, pump seals);
- pressure values in the oil system and coolant (air), as well as during the operation of supply, exhaust and general exchange ventilation systems, other mechanisms and systems.
If leaks or malfunctions are found, corrective action must be taken.
The installation of gas analyzer sensors in the pump room should be provided in accordance with the project at each pump in places where gas is most likely to accumulate and leaks of explosive vapors and gases (gland seals, mechanical seals, flange connections, valves, etc.).
Electric motors used to drive main pumps when they are located in the common hall must be explosion-proof, corresponding to the category and group of explosive mixtures. When non-explosion-proof electric motors are used to drive pumps, the electrical room must be separated from the pump room by a dividing wall. In this case, special devices are installed in the dividing wall at the junction of electric motors and pumps to ensure the tightness of the dividing wall (diaphragms with chambers for seamless connections), and an excess air pressure of 0.4 - 0.67 kPa should be provided in the electric room.
Starting the station is prohibited when the air temperature in the electrical room is below +5°C, in any start mode (automatic, remote or local).
Lubrication system
The installation of the oil system is carried out according to the drawings of the design organization in accordance with the oil supply scheme of the main pumps, with installation drawings and instructions from manufacturers. The project should provide for a backup lubrication system for the main equipment, which ensures the supply of oil to the units during emergency shutdowns. After graduation installation work pressure and drain oil pipelines and oil tank should be cleaned and flushed, filters cleaned and replaced.
During commissioning, oil is pumped through the oil system, the oil flow through the bearings is regulated by selecting throttle washers or a locking device. The oil system is checked for tightness of flange connections and fittings.
During commissioning, the reliability of oil supply from the accumulating oil tank (if provided) to the PU bearings is checked when the oil pumps are stopped to ensure the overrun of the main PU.
During the operation of the SE, the temperature and pressure of the oil at the inlet to the bearings of the units, the temperature of the bearings, etc. must be monitored. The mode in the oil cooling system must be maintained within the limits established by the technological protection settings map and ensure that the temperature of the bearings of the units does not exceed the maximum allowable values.
The level in the oil tanks and the oil pressure must be within the limits that ensure reliable operation of the pump bearings and electric motors. The control of the oil level in the oil tanks is carried out by the duty shift personnel. The oil pressure in the oil system is controlled automatically, the main pump units are provided with automatic protection for the minimum oil pressure at the inlet of the pump and motor bearings. Temperature, level and pressure control points in the lubrication system are determined by the project.
The oil in the lubrication system must be replaced with fresh set by the instruction operating time or after 3000 - 4000 hours of equipment operation.
For each type of ND, the frequency of sampling from the lubrication system to check the quality of the oil must be established. Samples must be taken in accordance with GOST 2517-85 “Oil and oil products. Sampling methods".
It is forbidden to use oils of grades that do not correspond to those recommended by the manufacturer (companies) in the lubrication system of ND bearings.
Oil from the supplier is accepted with a certificate of conformity and a quality certificate for the oil. In the absence of these documents, the acceptance of the oil should be carried out after carrying out the appropriate physical and chemical analyzes for the compliance of its parameters with the required ones and issuing an opinion by a specialized laboratory.
Installation of lubrication system elements (pipelines, filters, coolers, oil tank(s), etc.) must comply with the design and ensure gravity flow of oil into the oil tank(s) without the formation of stagnant zones; the values of the mounting slopes must comply with the requirements of the NTD. Filters should be located at the lowest points of the system or its parts. Elements of the lubrication system (filters) must be periodically cleaned within the time specified in the instructions.
For each type of pumps and motors, oil consumption rates are set on the basis of factory and operational data.
In the oil pumping (oil sump) should be posted approved by the technical manager of the PS, NP, etc. technology system lubrication systems indicating the permissible values of the minimum and maximum pressure and oil temperature.
Cooling system
Terms and methods of cleaning the cooling cavities of units and heat exchangers of the cooling system from scale and contaminated water should be established depending on the design of the cooling system, degree of contamination, hardness, water consumption. The pipelines of the cooling system must be made with a slope that ensures self-draining of water through special taps or fittings.
It is necessary to check the absence of oil or oil in the cooling water at least once per shift. If the latter are detected, measures are taken to immediately identify and eliminate the damage. The results of a shift check for the presence of oil or oil products in the water should be recorded in the logbook.
The cooling system must exclude the possibility of increasing the water pressure in the cooled cavities of the unit above the limit specified by the manufacturer. The liquid cooling temperature in front of the motor radiators must not exceed +33°C.
External elements of the cooling system (pipelines, fittings, cooling tower, tanks) must be prepared in time for operation in winter conditions or emptied and disconnected from the main system.
Air intake for engine cooling is carried out in accordance with the project in places that do not contain oil product vapors, moisture, chemicals, etc. above the limits. The temperature of the air supplied to cool the engines must comply with the design and manufacturer's instructions.
The pumping station must have a technological scheme of the cooling system approved by the technical manager of the LPDS, PS, NP, indicating the permissible values of pressure and temperature of the cooling medium.
Technological processes in the pumping station LPDS "Kaltasy" are accompanied by significant noise and vibration. Sources of intense noise and vibration include booster (20NDsN) and main (NM 2500-230, NM1250-260) pumps, elements of ventilation systems, pipelines for moving oil, electric motors (VAO - 630m, 2AZMV1 2000/6000) and other process equipment.
Noise affects the hearing organs, leading to partial or complete deafness, i.e. to occupational deafness. In this case, the normal activity of the nervous, cardiovascular and digestive systems is disrupted, resulting in chronic diseases. Noise increases the energy costs of a person, causes fatigue, which reduces the production activity of labor and increases marriage in work.
Prolonged exposure to vibration on a person causes occupational vibration disease. The impact on the biological tissue and nervous system of vibration leads to muscle atrophy, loss of elasticity of blood vessels, ossification of tendons, disruption of the vestibular apparatus, decreased hearing acuity, visual impairment, which leads to a decrease in labor productivity by 10-15% and is partly the cause of injuries. Noise regulation at workplaces, general requirements for noise characteristics of units, mechanisms and other equipment are established in accordance with GOST 12.1.003-83.
Table 4. - Permissible values of sound pressure level in the pump shop and vibration of the pump unit
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Place of measurement |
Sound level, dB |
Permissible according to the norm, dB |
Maximum speed, mm/s |
Emergency maximum, mm/s |
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pump house |
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Bearing vibration:
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Chassis vibration:
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Foundation vibration ON |
Noise and vibration protection is provided for by SN-2.2.4./2.1.8.566-96, consider the most typical measures for the pump shop:
- 1. remote control equipment;
- 2. sealing windows, openings, doors;
- 3. elimination of technical shortcomings and malfunctions of equipment that are a source of noise;
- 4. timely preventive maintenance according to the schedule, replacement of worn parts, regular lubrication of rubbing parts.
As individual means noise protection headphones or antiphons are used.
To reduce or eliminate vibration, SN-2.2.4./2.1.8.566-96 provides for the following measures:
- 1. correct design of bases for equipment, taking into account dynamic loads and their isolation from load-bearing structures and utilities;
- 2. alignment and balancing of the rotating parts of the units.
Workers exposed to vibration should undergo regular medical examinations.
The vibration of pumping units is mainly low- and medium-frequency of hydroaerodynamic origin. The vibration level according to survey data of some pumping stations exceeds sanitary norms 1-5.9 times (Table 29).
When vibration propagates through the structural elements of the units, when the natural vibration frequencies of individual parts turn out to be close and equal to the frequencies of the main current or its harmonics, resonant oscillations occur r threatening the integrity of some components and parts, in particular, the angular contact rolling bearing and oil pipelines of thrust bearings. One of the means of reducing vibration is to increase the losses due to inelastic resistance, i.e., applying to the pump and motor casing
Unit brand
24ND-14X1 NM7000-210
| 1,9-3,1 1,8-5,9 1,6-2,7 |
ATD-2500/AZP-2000
AZP-2500/6000
Note. Rotation speed 3000 rpm.
Anti-vibration coating, for example ShVIM-18 mastic. The source of low-frequency mechanical vibration of units on the foundation is the imbalance force and the misalignment of the pump and motor shafts, the frequency of which is a multiple of the shaft rotational speed divided by 60. Vibration caused by misalignment of the shafts leads to increased loads on the shafts and plain bearings, their heating and destruction, loosening of machines on the foundation, cutting off anchor bolts, and in some cases, to a violation of the explosion resistance of the electric motor. To reduce the vibration amplitudes of the shafts and increase the standard overhaul period of babbitt plain bearings up to 7000 motor-hours, the PS uses calibrated steel gasket sheets installed in the sockets of the bearing caps to select the wear gap.
The reduction of mechanical vibration is achieved by careful balancing and alignment of the shafts, timely replacement of worn parts and elimination of limiting clearances in bearings.
The cooling system must ensure that the temperature of the bearings does not exceed 60 °C. If the stuffing box becomes too hot, the pump should be stopped several times and immediately started to allow oil to seep through the packing. The absence of oil indicates that the stuffing box is packed too tightly and should be loosened. When a knock occurs, the pump is stopped to find out the cause of this phenomenon: they check the lubrication, oil filters. If the pressure loss in the system exceeds 0.1 MPa, the filter is cleaned.
Heating of the bearings, loss of lubrication, excessive vibration or abnormal noise indicate a problem with the pump unit. It must be stopped immediately to correct the detected problems. To stop one of the pumping units, close the valve on the discharge line and the valve on the hydraulic discharge line, then turn on the engine. After the pump has cooled, close all the valves of the pipelines supplying oil and water, and the valves at the pressure gauges. When the pump is stopped for a long time, to prevent corrosion, the impeller, sealing rings, shaft protection sleeves, bushings and all parts that come into contact with the pumped liquid should be lubricated, and the gland packing should be removed.
During the operation of pumping units, various malfunctions are possible, which can be caused by various reasons. Let's consider malfunctions of pumps and ways to eliminate them.
1. The pump cannot be started:
the pump shaft, connected by a gear coupling to the motor shaft, does not rotate - manually check the rotation! of the pump hall and the motor separately, the correct assembly of the gear coupling; if the shafts rotate separately, ta.216
check the centering of the unit; check the operation of the pump and wires when they are connected through a turbo transmission or gearbox;
the pump shaft, disconnected from the motor shaft, does not turn or rotates tightly due to the ingress of foreign objects into the pump, breakage of its moving parts and seals, jamming in the sealing rings - inspect, sequentially eliminating the detected mechanical damage.
2. The pump is started, but does not deliver liquid or after starting
submission is terminated:
the suction capacity of the pump is insufficient, since there is air in the intake pipeline due to incomplete filling of the pump with liquid or due to leaks in the suction pipeline, stuffing boxes - repeat filling, eliminate leaks;
incorrect rotation of the pump shaft - ensure the correct rotation of the rotor;
the actual suction height is greater than the permissible one, due to the mismatch of the viscosity, temperature or partial vapor pressure of the pumped liquid with the design parameters of the installation - provide the necessary backwater.
3. The pump consumes more power during start-up: ■
the valve on the discharge pipeline is open - close
gate valve during start-up;
impellers installed incorrectly - eliminate incorrect assembly;
seizing occurs in the sealing rings due to large clearances in the bearings or as a result of the displacement of the rotor - check the rotation of the rotor by hand; if the rotor turns hard, remove the jam;
the tube of the loading device is clogged - inspect and: clean the pipeline of the unloading device;
A fuse blows in one of the phases of the electric motor - replace the fuse.
4. The pump does not generate the calculated head:
reduced pump shaft speed - change the speed, check the engine and troubleshoot;
damaged or worn sealing rings of the impeller, leading edges of the impeller blades - replace the impeller and damaged parts;
the hydraulic resistance of the discharge pipeline is less than the calculated one due to a rupture of the pipeline, excessive opening of the valve on the discharge or bypass line - check the supply; if it has increased, then close the valve on the bypass line or cover it on the discharge line; eliminate various leaks in the discharge pipeline;
The density of the pumped liquid is less than the calculated one, the content of air or gases in the liquid is increased - check the density of the liquid and the tightness of the suction pipeline, stuffing boxes;
cavitation is observed in the suction pipeline or pump working elements - check the actual NPSH specific energy; at an underestimated value, eliminate the possibility of the appearance of a cavitation regime.
5. Pump flow less than calculated:
rotation speed is less than nominal - change the rotation speed, check the engine and eliminate faults;
the suction lift is greater than the permissible one, as a result of which the pump operates in cavitation mode - perform the work specified in paragraph 2;
the formation of funnels on the suction pipeline, not deep enough immersed in the liquid, as a result of which air enters with the liquid - install a cut-off valve to eliminate the funnel, increase the liquid level above the inlet of the suction pipeline;
increase in resistance in the pressure pipeline, as a result of which the pump discharge pressure exceeds the calculated one - fully open the valve on the discharge line, check all valves of the manifold system, linear valves, clean the clogs;
damaged or clogged impeller; increased gaps in the sealing rings of the labyrinth seal due to their wear - clean the impeller, replace worn and damaged parts;
Air enters through leaks in the suction pipeline or stuffing box - check the tightness of the pipeline, stretch or change the packing of the stuffing box.
6. Increased power consumption:
the pump flow is higher than the calculated one, the pressure is less due to the opening of the valve on the bypass line, the rupture of the pipeline or the excessive opening of the valve on the discharge pipeline - close the valve on the bypass line, check the tightness of the pipeline system or close the valve on the pressure pipeline;
damaged pump (worn impellers, O-rings, labyrinth seals) or motor - check pump and motor, repair damage.
7. Increased vibration and pump noise:
bearings are displaced due to the weakening of their fastening; worn bearings - check the shaft laying and the clearances in the bearings; in case of deviation, bring the size of the gaps to the permissible value;
the fastenings of the suction and discharge pipelines, foundation bolts and valves are loosened - check the fastening of the nodes and eliminate the shortcomings; 218
ingress of foreign objects into the flow part - clean the flow part;
the balance of the pump or the motor is disturbed due to the curvature of the shafts, their incorrect alignment or the eccentric installation of the coupling - check the alignment of the shafts and the coupling, eliminate damage;
increased wear and play in check valves and valves on the discharge pipeline - eliminate backlash;
the rotor balance is broken as a result of impeller clogging - clean the impeller and balance the rotor;
the pump operates in cavitation mode - reduce the flow by closing the valve on the discharge line, seal the connections in the suction pipeline, increase the back pressure, reduce the resistance in the suction pipeline.
8. Increased temperature of oil seals and bearings:
heating of the glands due to excessive and uneven tightening, small radial clearance between the pressure sleeve and the shaft, installation of the sleeve with a warp, jamming or distortion of the gland lantern, insufficient supply of sealing fluid - loosen the seals; if this does not give an effect, then disassemble and eliminate installation defects, replace the packing; increase the supply of sealing fluid;
heating of bearings due to poor oil circulation in the forced lubrication system of bearings, lack of rotation of the rings in bearings with ring lubrication, oil leakage and contamination - check the pressure in the lubrication system, the operation of the oil pump and eliminate the defect; ensure the tightness of the oil bath and pipeline, change the oil;
heating of the bearings due to improper installation (small clearances between the bushing and the shaft), wear of the bearings, excessive tightening of the support rings, small gaps between the washer and the rings in the thrust bearings, scuffing of the thrust or thrust bearing or melting of the babbit - check and eliminate defects; clean the burrs or replace the bearing.
Piston compressors. Parts where the most dangerous defects are possible include shafts, connecting rods, crossheads, rods, cylinder heads, crank pins, bolts and studs. The zones in which the maximum concentration of stresses is observed are threads, fillets, mating surfaces, pressings, necks and cheeks of columnar shafts, keyways.
During operation of the frame (bed) and guides, the deformation of their elements is checked. Vertical movements greater than 0.2 mm are a sign that the compressor is not working. Cracks are detected on the surface of the frame and their development is controlled.
The fit to the foundation of the frame, as well as any of the guides fixed on the foundation, must be at least G) 0% of the perimeter of their common joint. At least once a year, the horizontal position of the frame is checked (the deviation of the frame plane in any direction over a length of 1 m should not exceed 2 mm). On the sliding surfaces of the guides there should be no scratches, dents, nicks with a depth of more than 0.3 mm. For the crankshaft during operation, the temperature of its sections operating in the friction mode is controlled. It must not exceed the values specified in the operating instructions.
For connecting rod bolts, their tightening, the state of the locking device and the surface of the bolt are controlled. The signs of bolt inoperability are as follows: the presence of cracks on the surface, in the body or thread of the bolt, corrosion in the fitting part of the bolt, stripping or crushing of the threads. The total contact area should be at least 50 ° / about the area of the support belt. have breaks exceeding 25% of the circumference If the residual elongation of the bolt exceeds 0.2% of its original length, the bolt is rejected.
For the crosshead, the condition of the elements of its connection with the rod, as well as the pin, is checked, the gaps between the upper guide and the crosshead shoe are checked. During operation, pay attention to the condition of the outer surface of the cylinder, the sealing of the oil lines of the indicator plugs, and the flange connections of the water cooling system. Fistulas and passes of gas, water, oil in the case or flange connections are not allowed. The water temperature at the outlet of the water jackets and cylinder heads must not exceed the values given in the operating instructions.
For pistons, the condition of the surface is subject to control (including the condition and thickness of the bearing surface of the sliding type piston), as well as the fixation of the piston on the rod and plugs (for cast pistons) of the pressure stage. Signs of piston rejection are as follows: scoring in the form of grooves on an area constituting more than 10% of the casting surface, the presence of areas with lagged, melted or crumbled babbit, as well as cracks with a closed contour. The radial crack in the pour layer should not decrease to 60% of the original. Violations of the fixation of the piston nut for the plugs of cast pistons, piston play on the rod, leakage of the surface of the welds, separation of the piston bottom from the stiffeners are not allowed.
For rods, before taking the compressor out for repair, they control the beating of the rod within the stage piston, the state of the rod surface; scoring or traces of enveloping of the metal of the sealing elements on the surface of the rod are detected. No cracks on surface, threads or 220
stem fillets, deformation, thread breakage or collapse. During operation, the tightness of the stem seal, which is not equipped and equipped with a leak removal system, is checked. The indicator of tightness of the seals of the rods is the gas content in the controlled places of the compressor and the room, which should not exceed the values allowed by the current standards.
Check the condition of the stem seal annually during repairs. Cracks on the element or its breakage are unacceptable. The wear of the sealing element should be no more than 30% of its nominal radial thickness, and the gap between the stem and the protective ring of the stem seal with non-metallic sealing elements should not exceed 0.1 mm.
During operation, the performance of piston rings is monitored according to regulated pressures and temperatures of the compressible medium. There should be no increase in noise or knocking in the cylinders in the cylinders. Seizure of the sliding surface of the rings must be less than 10% of the circumference. If the radial wear of the ring in any of its sections exceeds 30% of the original thickness, the ring is discarded.
The signs of valve inoperability are as follows: abnormal knocking in the valve cavities, deviations in pressure and temperature of the compressible medium from the regulated ones. When monitoring the condition of the valves, the integrity of the plates, springs and the presence of cracks in the valve elements are checked. The area of the valve flow section as a result of contamination should not decrease by more than 30% of the original, and the density should not be below the established norms.
Piston pumps. Cylinders and their liners may have the following defects: wear of the working surface as a result of friction, corrosion and erosion wear, cracks, scoring. The amount of cylinder wear is determined after the piston (plunger) is removed by measuring the diameter of the bore in the vertical and horizontal planes in three sections (middle and two extreme) using a micrometric pin.
On the working surface of the piston, scuffing, nicks, burrs and torn edges are unacceptable. The maximum allowable wear of the piston is (0.008-0.011) G> n, where About l- minimum piston diameter. If cracks are found on the surface of the piston rings, significant and uneven wear, ellipse, loss of elasticity of the rings, they must be replaced with new ones.
The rejection gaps of the piston rings of the pump are determined as follows: the smallest gap in the ring lock in the free state D "(0.06 ^ -0.08) B; the largest gap in the lock of the ring in working condition L \u003d k (0.015-^0.03) D where O is the minimum diameter of the cylinder.
Permissible radial warping for rings with a diameter of up to 150, 150-400, over 400 mm is, respectively, no more than 0.06-0.07; 0.08-0.09; 0.1-0.11 mm.
The rejection gap between the rings and the walls of the piston grooves is calculated according to the following ratios: L t y = = 0.003 /g; A t ah \u003d (0.008-4-9.01) to, where to- nominal height of the rings.
Upon detection of scratches with a depth of 0.5 mm, ellipsoidality of 0.15-0.2 mm, the rods and plungers are machined. The stem can be machined to a depth of no more than 2 mm.
The misalignment of the cylinder and the rod guide is allowed within 0.01 mm. If the runout of the rod exceeds 0.1 mm, then the rod is machined for 7 g of the runout value or corrected.
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Vibrodiagnostics allows you to control the technical condition of the main and supporting units in the mode of continuous monitoring of the vibration level.
Basic requirements for monitoring and measuring vibrations of pumping units:
1. All mainline and booster pumping units must be equipped with stationary monitoring and signaling vibration equipment (KSA) with the possibility of continuous monitoring of the current vibration parameters in the operator room. The PS automation system should provide light and sound alarms in the control room in case of increased vibration, as well as automatic shutdown units when reaching the emergency value of vibration.
2. Sensors of the control and signal vibration equipment are installed on each bearing support of the main and horizontal booster pumps to control vibration in the vertical direction. (fig) On vertical booster pumps, sensors are installed on the housing of the thrust bearing assembly to monitor vibration in the vertical (axial) and horizontal-transverse directions. (fig)
Picture. Measuring points on the bearing pedestal
Picture. Vibration measuring points on the vertical pump unit
The automation system must be configured to issue a signal when the warning and emergency levels of pump vibration at controlled points are reached. The measured and normalized vibration parameter is the mean square value (RMS) of the vibration velocity in the operating frequency band of 10…1000 Hz.
3. The values of the alarm and protection settings for excessive vibration are set according to the approved process protection settings map depending on the rotor size, pump operation mode (supply) and vibration standards.
Vibration standards for main and booster pumps for nominal operating modes
Vibration standards for main and booster pumps for non-rated operating modes
With a vibration value of 7.1 mm/s to 11.2 mm/s, the duration of operation of the main and booster pumps should not exceed 168 hours.
The nominal mode of operation of the pumping unit is the supply from 0.8 to 1.2 of the nominal supply (Q nom) of the corresponding rotor (impeller).
When turning on and off the pumping unit, the protection of this unit and other operating units should be blocked due to excessive vibration for the duration of the program for starting (stopping) the pumping units.
4. Warning signaling in the operator's room of the local control room in terms of the "increased vibration" parameter corresponds to the RMS value of 5.5 mm/s (nominal mode) and 8.0 mm/s (non-nominal mode).
Signal "emergency vibration" - RMS 7.1 mm/s and 11.2 mm/s, immediate shutdown of the pumping unit.
5. Vibration control of auxiliary pumps (oil pumps, pumps of pumping systems for leaks, water supply, fire extinguishing, heating) should be carried out once a month and before being put into Maintenance using portable equipment.
6. To obtain additional information during vibration diagnostics of main and retaining units, as well as for the period of temporary absence of permanently installed means for measuring and monitoring vibration (verification, calibration, modernization), portable portable vibration equipment is used.
Each measurement of vibration by portable equipment is carried out at strictly fixed points.
7. When using portable vibration equipment, the vertical component of the vibration is measured on the top of the bearing cap above the middle of the bearing shell length.
The horizontal-transverse and horizontal-axial vibration components of horizontal pumping units are measured 2…3 mm lower from the axis of the pump shaft opposite the middle of the length of the support insert (Fig.).
Vibration measurement points on the vertical pump unit correspond to points 1, 2, 3, 4, 5, 6 (fig.).
Picture. Vibration measuring points on the pump bearing housing without outriggers
For pumps that do not have remote bearing units (such as CNS, NGPNA), vibration is measured on the housing above the bearing as close as possible to the axis of rotation of the rotor (Fig.).
8. To assess the rigidity of the frame attachment to the foundation, vibration is measured on all elements of the pump attachment to the foundation. The measurement is made in the vertical direction on the anchor bolts (heads) or next to them on the foundation at a distance of no more than 100 mm from them. The measurement is carried out with planned and unscheduled vibration diagnostics control.
9. To carry out vibration diagnostic control, equipment is used to measure the root-mean-square value of vibration and universal vibration-analyzing equipment with the ability to measure the spectral components of vibration and amplitude-phase characteristics.
GOST 30576-98
INTERSTATE STANDARD
Vibration
CENTRIFUGAL PUMPS
NUTRITIONAL HEAT
POWER PLANTS
Vibration standards and general requirements for measurements
INTERSTATE COUNCIL
ON STANDARDIZATION, METROLOGY AND CERTIFICATION
Minsk
Foreword
1 DEVELOPED by the Interstate Technical Committee for Standardization MTK 183 "Vibration and Shock" with the participation of the Ural Thermal Engineering Research Institute (JSC UralVTI) INTRODUCED by the State Standard of Russia2 ADOPTED by the Interstate Council for Standardization, Metrology and Certification (minutes No. 13 - 98 dated May 28, 1998 ) Voted for adoption: 3 by the Resolution of the State Committee Russian Federation on standardization and metrology dated December 23, 1999 No. 679-st, the interstate standard GOST 30576-98 was put into effect directly as the state standard of the Russian Federation from July 1, 20004 INTRODUCED FOR THE FIRST TIME
INTERSTATE STANDARD
Vibration
CENTRIFUGAL FEED PUMPS FOR THERMAL POWER PLANTS
Vibration standards and general requirements for measurements
mechanical vibration. Centrifugal feed pumps for thermal stations.
Evaluation of machine vibration and requirements for the measurement of vibration
Introduction date 2000-07-01