The faults of the reversing valve of the cutting machine are: the valve cannot reverse or the reversing action is slow, gas leakage, electromagnetic pilot valve has faults, etc.
(1) the reversing valve cannot or the reversing action is slow, generally due to poor lubrication, spring is stuck or damaged, oil or impurities stuck sliding part and other reasons caused. To this, should check whether the oil mist device work normally first; Whether the viscosity of the lubricating oil is suitable. If necessary, replace the lubricating oil, clean the sliding part of the reversing valve, or replace the spring and the reversing valve.
(2) after a long use of the cutting machine's reversing valve, it is easy to appear the phenomenon of spool sealing ring wear, stem and seat damage, resulting in the leakage of gas in the valve, the valve's slow or can not normally reverse and other faults. At this point, replace the seal ring, stem and seat, or replace the reversing valve.
(3) if the inlet and exhaust holes of the electromagnetic pilot valve are blocked by oil sludge and other debris, the closure is not strict, the movable iron core is stuck, the circuit has faults, etc., can lead to the valve can not be normal reversing. For the first three cases should be cleaned pilot valve and movable iron core on the sludge and impurities. Circuit faults are generally divided into control circuit faults and electromagnetic coil faults. Before checking the circuit fault, the manual knob of the reversing valve should be first rotated a few times to see whether the reversing valve can normally reverse under the rated air pressure, if it can reverse normally, it is the circuit fault. During the inspection, the voltage of the electromagnetic coil can be measured with a meter 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 trip switch circuit should be further checked. If the reversing valve does not normally reverse at the rated voltage, check whether the connector (plug) of the solenoid coil is loose or not in contact. The method is to unplug the plug and measure the resistance value of the coil. If the resistance value is too large or too small, the coil is damaged and should be replaced.