Abstract: The hydraulic drive fast off valve maintenance method and maintenance points.
Keywords: quick closing valve; hydraulic actuator; maintenance; maintenance
1 Overview
Butterfly valve hydraulic drive unit of Fast electric cut-off valve and check valve to resolve can not be fast off (> 1s) of the turbine speed caused the problem. When the crew when the accident occurred, fast off valve hydraulic driving system can quickly drive the valve closed, to effectively prevent the tail steam turbine and condensed water intrusion, and instantly cut off the pipeline to protect turbine. From this quick closing valve hydraulic drive devices are safety devices to ensure the normal operation of its own it is very necessary, correct maintenance and repair is essential to ensure normal operation of equipment condition, following the introduction of hydraulic drive fast off valve Device maintenance method and maintenance points.
2 Maintenance of
Butterfly valve hydraulic drive fast off the normal operation of routine maintenance needs, if not pay attention to routine maintenance of equipment and maintenance, fast off valve hydraulic driving system prone to failure. Operators should always observe the hydraulic system pressure, noise, vibration, oil temperature, oil level, voltage, trip switches and leakage issues, to solve the problem once found. Appropriate maintenance method can reduce the speed off valve hydraulic drive failure, soon off to extend the service life of hydraulic driving system valve, butterfly valve hydraulic drive fast off the daily maintenance of the methods are the following.
(1 ) quick closing valve hydraulic drive unit in the installation is complete, at a time when fuel tank must be in accordance with the instructions given grade fuel, to replace oil with other manufacturers must do after
Recognition can change, new oil should be filtered before entering the tank, oil pollution requires a system to NAS8 above grade.
(2 ) quick closing valve hydraulic drive unit in the first run after installation, make sure the motor direction is correct. Can to move the motor to determine if the direction is inconsistent with the specification requirements of the direction, will have to change the wiring. Motor in the right direction not recognized before, do not start a long motor, so as not to damage the pump.
(3 ) quick closing valve hydraulic drive unit in the first run after installation, should the relief valve completely loose, and then slowly to raise the pressure to increase 1MPa suitable, and the pressure in each segment to run 5min, After confirming that no abnormal then further up, until the pressure up to meet the specification requirements. Occurred during the pressure test failure should be immediately removed. Troubleshooting must be in relief after. If the welds need to re- welding, the parts must be removed, in addition to a net oil only after welding.
(4 ) are not allowed to campaign in the implementation of component -conditioning system under pressure. Surge preceded Check pressure gauge, pressure regulator without gauge system allowed. After the pressure regulator adjustment screw should be locked to prevent loosening. To regularly check the pressure gauge is correct and reliable.
(5 ) quick closing valve hydraulic drive unit in the first run before the installation is complete, should the gas pressure inside the accumulator filling with nitrogen pressure to specification requirements , must not be replaced with oxygen, otherwise it will create a major accident. Equipment in the transport process does not allow the accumulator with pressure, so prone to explosion.
(6 ) should be periodically (one month ) to check the tank liquid height. The first refueling over the proposed increase to the level gauge, oil level under normal working conditions required in the level gauge 1 / 2 height position lower than the level gauge 1 / 3 height to refuel, with a " low level "control Protection, level too low in oil-source system will stop working, until the filling to the required scale, the system can restart.
(7 ) initially should be on a regular basis (one month ) to check the gas pressure accumulator, air pressure below the specification requirement of 10% nitrogen should be added to the pressure of nitrogen pressure to meet the specification requirements. Six months later, can be inspected at the first quarter of the gas pressure inside the accumulator.
(8 ) quick closing valve in the hydraulic drive unit production run process, should pay attention to changes in oil condition regularly ( quarterly ) sample for testing. If the oil does not meet the requirements found to be timely or replaced with new oil purification, oil pollution requires a system to keep NAS8 above grade.
(9 ) regular checks of hydraulic driving system quick closing valve power supply voltage, supply voltage fluctuation range of the rated voltage within ± 10%. Special attention to the power supply voltage electromagnetic valve, the supply voltage deviation range of ± 10% of rated voltage in order to ensure that the solenoid valve to operate correctly.
(10 ) regular checks of hydraulic driving system quick closing valve in all filters. Police discovered oil contamination, the timely replacement of filter cartridges. If found to have serious damage to filter, oil tank must be replaced or filter.
( 1.) quick closing valve after the hydraulic driving system in operation, require frequent operation of the local observation device, if fault indication, oil spills and other abnormal phenomenon, so that a timely manner.
(12 ) according to design requirements and work requirements, a reasonable adjustment valve hydraulic drive fast off the work pressure and pace of work. Pressure valve, control valve transferred to the required value, the adjustment screw should be tightened to prevent loosening.
(13 ) quick closing valve hydraulic driving system should pay attention to moisture, anti- loose, corrosion, dust and impact, etc. .
(14 ) quick closing valve hydraulic drive oil operating temperature must not exceed 55 ℃, if the oil temperatures in excess of 55 ℃ to give the reasons identified solution.
(15 ) quick closing valve hydraulic drive unit of the pressure hose and seals should be changed regularly (usually 2a).
(16 ) always check pressure switch and limit switch action is normal, if not normal to change in time.
3 Maintenance Points
Butterfly valve hydraulic drive fast off the event of a failure to timely repair, the repair should pay attention to the following points.
(1 ) quick closing valve hydraulic driving system failure according to hydraulic and electrical schematic diagram careful analysis, to identify the point of failure, determine the method of repair.
(2 ) of the hydraulic components or piping or seals to replace, should the oil discharge pressure accumulator, in order to avoid injection or wounding of the accident.
(3 ) the replacement of the electrical components, it should turn off the power supply to avoid electric shock accidents.
(4 ) If you need to replace the hydraulic components and electrical components, should check the model, identifying the time and storage environment, storage devices, should pay attention to the internal components of aging, if necessary, should be removable and washable, replacement and performance testing.
(5 ) If the need for threaded cartridge valves for maintenance, decommissioning of the former to understand the principles and structure , demolition should use the appropriate openings in the package jaw chuck topspin Kai, assembly should be used when appropriate in the opening set of three Jaw chuck on the tightened assembly thread Department would also like to use removable strength thread locking agent.
(6 ) If the need for the cartridge valve replacement, valve sleeve removal tool to use when specific, or difficult to demolition. In the second cartridge valve assembly, be coated with oil, cover with screws and slowly pressed into, not to tap into.
(7 ) maintenance of hydraulic components used to check the connection bolts of material and intensity to meet the design requirements and hydraulic parts manufacturer requirements. Valve block to connect the hydraulic valve is best to use measured force bolt wrench to tighten, tightening torque should be consistent with the provisions of the hydraulic valve manufacturer.
(8 ) If you need to replace the hydraulic pump, hydraulic pump is installed, the hydraulic pump and motor to ensure the concentricity between the two axis tolerance, parallelism tolerance compliance, or not greater than the coupling between the pump and motor Manufacturer recommended the concentricity and parallelism requirements. We should tighten access to pipeline, to ensure no leakage.
4, treatment of common faults
Butterfly valve hydraulic drive unit of Fast Fault processing method, see " Table 1. "
| Serial number | Phenomenon | Analysis | Treatment |
|---|---|---|---|
| 1 | Power indicator does not light | 1. Check that the power is normal 2. Check whether the electrical control box close the circuit breaker 3. Check electrical control box switching power supply is normal 4. Check on the circuit board fuse blown |
1. enter the normal power supply 2. Close the circuit breaker 3. Replacement Power Supply 4. Replace the fuse |
| 2 | The failure of local | 1. " Power "light is lit 2. " Local / Remote " switch is pull to the local gear |
1. by an processing 2. Switch to the local gear |
| 3 | Remote Operation Failure | 1. " Power "light is lit 2. " Local / Remote " switch is pull to the remote gear |
1. by an processing 2. Switch to the remote gear |
| 4 | Pressure gauge shows zero pressure | 1. the system is started 2. pump motor is running, the electrical overload or a lack of phase 3. oil discharge valve is opened |
1. Start System 2. to eliminate the overload factor ( pump or shaft to be stuck ) to check the power 3. close the oil drain valve |
| 5 | Cylinder does not move | 1. Check whether the operation is effective 2. Check oil pressure is normal 3. Check whether the solenoid valve coil may call the normal 4. Check valve is stuck or burned 5. Check hydraulic valve is stuck |
1. according to two treatment 2. according to four treatment 3. charged the correct configuration requirements 4. Remove and clean or replace 5. disassembled and cleaned or replaced |
| 6 | Oil pollution | 1. to replace the oil filter or filter | |
| 7 | Motor has been run or time out | 1. Check maximum pressure limiting switch 2. Check Relief Valves |
1. to adjust or replace pressure switch 2. re- regulating relief valve |
| 8 | " oil pressure "and do not operate motor | 1. check the lower limit pressure switch 2. Check pump motor and control circuit |
1. to adjust or replace pressure switch 2. according to four treatment |
| 9 | Poor packing performance | 1. Check whether the leakage of electromagnetic valve 2. check the throttle valve is closed tightly 3. Check whether the inner tank leaks 4. Check whether the leak check valve |
1. Repair or replace solenoid valve 2. firmly closed throttle valve 3. replace cylinder seals 4. to replace a one-way valve |
| 10 | Cylinder stop instability | 1. Check whether the leakage of hydraulic lock 2. Check whether the inner tank leaks |
1. Repair or replace hydraulic lock 2. replace cylinder seals |
5 Conclusion
Hydraulic drive fast off valve is safe equipment, understand the main points of maintenance methods and maintenance is very necessary, this combined with the actual right Kuai Guan butterfly valve hydraulic drive unit of the maintenance method and maintenance Yaodian for Le summary, hope it’ll be help.