Close the butterfly valve quicklyMaintenance Method

The normal operation of the hydraulic drive device for the quick closing butterfly valve requires daily maintenance. If the equipment is not maintained regularly, the hydraulic drive device for the quick closing butterfly valve is prone to malfunction. Operators should regularly observe hydraulic system pressure, noise, vibration, oil temperature, oil level, voltage, travel switches, and leaks. Once problems are discovered, they should be promptly resolved. Appropriate maintenance methods can reduce the failure of the hydraulic drive device for fast closing butterfly valves and extend the service life of the hydraulic drive device. The daily maintenance methods for the hydraulic drive device of fast closing butterfly valves mainly include the following aspects.

(1) After the installation of the quick closing butterfly valve hydraulic drive device, when refueling the oil tank, it is necessary to refuel according to the specified brand in the manual. If other oil products are to be used as substitutes, confirmation from the manufacturer must be obtained before making changes. New oil products must also be filtered before entering the oil tank, and the pollution level of the system oil must reach NAS8 or above.

(2) When the hydraulic drive device for the quick closing butterfly valve is first operated after installation, it is necessary to confirm whether the direction of the motor is correct. It can be determined by inching the motor. If the direction is not consistent with the direction required in the manual, the wiring needs to be changed. Do not operate the motor for a long time without confirming the correct direction of the motor to avoid damaging the oil pump.

(3) Before the hydraulic drive device of the quick closing butterfly valve is operated for the first time after installation, the overflow valve should be loosened, and the pressure should be slowly increased in increments of 1MPa. It is recommended to run for 5 minutes in each pressure section, confirm that there are no abnormalities, and then increase it again until the required pressure in the manual is reached. Malfunctions that occur during the pressure test should be promptly resolved. Troubleshooting must be carried out after pressure relief. If the weld seam needs to be re welded, the part must be removed and the oil stains must be removed before welding.

(4) Do not adjust system pressure while executing component motion. Before adjusting the pressure, the pressure gauge should be checked first. Systems without pressure gauges are not allowed to adjust the pressure. After pressure adjustment, the adjustment screw should be locked to prevent loosening. Regularly check whether the pressure gauge is correct and reliable.

(5) Before the hydraulic drive device of the quick closing butterfly valve is operated for the first time after installation, the gas pressure in the accumulator should be filled with nitrogen to the required pressure in the manual. Oxygen should not be used as a substitute, otherwise it may cause major accidents. During the transportation of the equipment, it is not allowed for the accumulator to be pressurized, as this can easily lead to explosions.

(6) The fuel tank level should be checked regularly (once a month). *It is recommended to fill the liquid level gauge to the full level during refueling. Under normal working conditions, the oil level should be at least 1/2 of the height of the level gauge. When it is lower than 1/3 of the height of the level gauge, refueling must be done. With the "low liquid level" control protection, the oil source system will stop working when the liquid level is too low. The system can only be restarted when the oil level reaches the required mark.

(7) At the beginning, the gas pressure inside the accumulator should be checked regularly (one month). If it is lower than the required inflation pressure in the manual by 10%, nitrogen should be replenished to make the nitrogen pressure reach the required pressure in the manual. Six months later, the gas pressure inside the accumulator can be checked once a quarter.

(8) During the production and operation of the hydraulic drive device for quick closing butterfly valves, attention should be paid to the changes in oil quality, and regular (quarterly) sampling and testing should be conducted. If the oil quality does not meet the requirements, it should be promptly purified or replaced with new oil, and the pollution level of the system oil should be maintained at NAS8 or above.

(9) Regularly check the voltage of the hydraulic drive device for the quick closing butterfly valve, and ensure that the voltage fluctuation range of the power supply is within ± 10% of the rated voltage. Pay special attention to the power supply voltage of the solenoid valve, with a deviation range of ± 10% of the rated voltage, to ensure that the solenoid valve can operate normally.

(10) Regularly check the various filters of the hydraulic drive device of the quick closing butterfly valve. When an oil contamination alarm is detected, replace the filter element of the filter in a timely manner. If serious damage is found to the filter element, the oil tank must be replaced or filtered.

(1.) After the hydraulic drive device of the quick closing butterfly valve is put into operation, it is necessary to frequently observe the operation of the device locally. If there are any abnormal phenomena such as fault indications or oil leakage, they should be dealt with in a timely manner.

(12) Reasonably adjust the working pressure and speed of the hydraulic drive device of the quick closing butterfly valve according to the design regulations and work requirements. When adjusting the pressure valve and speed control valve to the required values, the adjusting screws should be tightened to prevent loosening.

(13) The hydraulic drive device of the quick closing butterfly valve should pay attention to moisture prevention, loosening prevention, corrosion prevention, dust prevention, and anti-collision.

(14) The working temperature of the hydraulic drive device for the quick closing butterfly valve should not exceed 55 ℃. If the working temperature of the oil exceeds 55 ℃, the cause must be identified and resolved.

(15) The high-pressure hose and seals of the hydraulic drive device for the quick closing butterfly valve should be replaced regularly (usually 2a).

(16) Regularly check if the pressure relay and travel switch are functioning properly, and replace them promptly if they are not functioning properly.

Close the butterfly valve quicklyMaintenance points

Once the hydraulic drive device of the quick closing butterfly valve malfunctions, it should be repaired in a timely manner, and the following points should be noted during maintenance.

(1) When the hydraulic drive device of the quick closing butterfly valve malfunctions, it is necessary to carefully analyze the hydraulic and electrical schematics, identify the fault point, and determine the repair method.

(2) When replacing hydraulic components, pipelines, or seals, the pressure oil of the accumulator should be released to avoid accidents such as fuel injection or injury.

(3) When replacing electrical components, the power should be turned off to avoid electric shock accidents.

(4) If hydraulic and electrical components need to be replaced, the model should be checked, the storage time and environment of the components should be determined, and attention should be paid to the degree of aging inside the components. If necessary, disassembly, cleaning, replacement, and performance testing should be carried out.

(5) If it is necessary to repair the threaded plug valve, the principle and structure should be understood before disassembly. When disassembling, a suitable opening sleeve should be used to unscrew it on the three jaw chuck. When assembling, a suitable opening sleeve should also be used to tighten it on the three jaw chuck. Medium strength detachable thread locking agent should also be used at the thread during assembly.

(6) If it is necessary to replace the two-way plug-in valve, tools should be used when disassembling the valve sleeve, otherwise it will be difficult to disassemble. When assembling a two-way plug-in valve, apply lubricating oil and slowly press it in with screws and cover plates. Do not knock or drive it in.

(7) During maintenance, it is necessary to check whether the material and strength of the connecting bolts used for hydraulic components meet the design requirements and the requirements specified by the hydraulic component manufacturer. The connecting bolts of each hydraulic valve on the valve block should be tightened with a torque wrench, and the tightening torque should comply with the regulations of the hydraulic valve manufacturer.

(8) If it is necessary to replace the hydraulic pump, when installing the hydraulic pump, it is necessary to ensure that the coaxiality tolerance and parallelism tolerance between the two shafts of the hydraulic pump and the motor meet the regulations, or not exceed the coaxiality and parallelism requirements recommended by the coupling manufacturer between the pump and the motor. Tighten the inlet and outlet oil pipes to ensure no leakage.

Common troubleshooting methods

The common troubleshooting methods for hydraulic drive devices of quick closing butterfly valves are shown in Table 1.

Table 1 Common troubleshooting methods for hydraulic drive devices of quick closing butterfly valves

serial number	phenomenon	Root cause analysis	treatment method
1	The power indicator light is not on	1. Check if the power supply is working properly 2. Check if the circuit breaker inside the electrical control box is closed 3. Check if the switch power supply inside the electrical control box is normal 4. Check if the fuse on the circuit board is blown	1. Input normal power supply 2. Close the circuit breaker 3. Replace the switch power supply 4. Replace the fuse
2	Local operation failure	1. Is the "power" indicator light on 2. Is the "local/remote" toggle switch turned to the local gear	1. Handle according to one item 2. Switch to local gear
3	Remote operation failure	1. Is the "power" indicator light on 2. Is the "local/remote" toggle switch turned to the remote gear	1. Handle according to one item 2. Switch to remote gear
4	The pressure gauge shows zero pressure	1. Has the system started 2. Whether the oil pump motor is running, motor overload or phase loss 3. Drain the oilglobe valveWhether to open	1. Start the system 2. Eliminate overload factors (oil pump or shaft stuck) and check the power supply 3. Close the oil drain shut-off valve
5	The oil cylinder does not move	1. Check if the operation is effective 2. Check if the oil pressure is normal 3. Check if the solenoid valve coil is powered normally 4. Check if the solenoid valve is stuck or burnt out 5. Check if the hydraulic valve is stuck	1. Handle according to 2 items 2. Handle according to 4 items 3. Configure live according to the correct requirements 4. Disassemble and clean or replace 5. Disassemble and clean or replace
6	Oil contamination		1. Replace the oil or even the filter element of the filter
7	Motor running continuously or exceeding the time limit	1. Check the upper limit voltage switch 2. Check the overflow valve	1. Adjust or replace the pressure relay 2. Readjust the overflow valve
8	Low oil pressure and motor not running	1. Check the lower limit voltage switch 2. Check the oil pump motor and control circuit	1. Adjust or replace the pressure relay 2. Handle according to 4 items
9	Poor pressure holding performance	1. Check the electromagnetic fieldball valveIs there a leak 2. Check if the throttle stop valve is tightly closed 3. Check if there is any internal leakage in the oil cylinder 4. Check if the one-way valve leaks	1. Repair or replace the electromagnetic ball valve 2. Tighten the throttle stop valve 3. Replace the sealing ring of the oil cylinder 4. Replace the one-way valve
10	The oil cylinder cannot stop stably	1. Check if the hydraulic lock is leaking 2. Check if there is any internal leakage in the oil cylinder	1. Repair or replace hydraulic lock 2. Replace the sealing ring of the oil cylinder

Conclusion

The hydraulic drive device for quick closing butterfly valves belongs to safety equipment, and it is necessary to understand its maintenance methods and repair points. This article summarizes the maintenance methods and repair points of the hydraulic drive device for quick closing butterfly valves based on practical experience, hoping to be helpful to everyone.