The faults of the reversing valve include: the valve cannot be reversed or the reversing action is slow, gas leakage, the electromagnetic pilot valve is faulty, etc.
(1) The reversing valve cannot be reversed or the reversing action is slow, which is generally caused by poor lubrication, stuck or damaged springs, oil or impurities stuck on the sliding part, etc. In this regard, you should first check whether the lubricator works normally; whether the viscosity of the lubricating oil is appropriate. If necessary, replace the lubricating oil, clean the sliding part of the reversing valve, or replace the spring and reversing valve.
(2) After the reversing valve is used for a long time, the valve core sealing ring is prone to wear and the valve stem and valve seat are damaged, resulting in the leakage of gas in the valve, the slow movement of the valve or the failure of normal reversing. At this time, the sealing ring, valve stem and valve seat should be replaced, or the reversing valve should be replaced.
(3) If the inlet and exhaust holes of the electromagnetic pilot valve are blocked by sludge and other debris, the sealing is not strict, the movable iron core is stuck, and the circuit is faulty, etc., all of which may cause the reversing valve to fail to change direction normally. For the first three cases, the sludge and impurities on the pilot valve and the movable iron core should be cleaned. Circuit faults are generally divided into two categories: control circuit faults and electromagnetic coil faults. Before checking the circuit fault, turn the manual knob of the reversing valve a few times to see if the reversing valve can be reversed normally under the rated air pressure. If it can be reversed normally, the circuit is faulty. When checking, the voltage of the solenoid coil can be measured by the instrument to see if the rated voltage has been reached. If the voltage is too low, the power supply in the control circuit and the associated travel switch circuit should be further checked. If the reversing valve cannot be reversed normally under the rated voltage, check whether the connector (plug) of the solenoid coil is loose or not in solid contact. The method is to unplug the plug and measure the resistance of the coil (generally between several hundred ohms and several thousand ohms). If the resistance is too large or too small, the solenoid coil is damaged and should be replaced.