SMC电磁阀故障有：阀不能换向或换向动作缓慢，气体泄漏，电磁先导阀有故障等。
1：SMC电磁阀时间使用后易出现阀芯密封圈磨损、阀杆和阀座损伤的现象，封闭不严，活动铁芯被卡死，电路有故障等，此时，应更换密封圈、阀杆和阀座，或将换向阀换。2：若SMC电磁阀先导阀的进、排气孔被油泥等杂物堵塞，导致阀内气体泄漏，阀的动作缓慢或不能正常换向等故障。均可导致换向阀不能正常换向。3：SMC电磁阀不能换向或换向动作缓慢，般是因润滑不良、弹簧被卡住或损坏、油污或杂质卡住滑动部分等原因引起的。对此，应先检查油雾器的工作是否正常；润滑油的粘度是否合适。必要时，应更换润滑油，清洗换向阀的滑动部分，或更换弹簧和换向阀。对前3种情况应清洗先导阀及活动铁芯的油泥和杂质。而电路故障般又分为控制电路故障和电磁线圈故障两类。检查时，可用仪表测量电磁线圈的电压，看是否达到了额定电压，如果电压过，应进步检查控制电路中的电源和相关联的行程开关电路。如果阻值太或太，说明电磁线圈已损坏，应更换。如果在额定电压下换向阀不能正常换向，则应检查电磁线圈的接头（插头）是否松动或接触不实。方法是，拔下插头，测量线圈的阻值，在检查电路故障前，应先将换向阀的手动旋钮转动几下，看换向阀在额定的气压下是否能正常换向，若能正常换向，则是电路有故障。www.san17.com
SMC solenoid valve failure are: the valve can not change or change to the slow, gas leak, solenoid pilot valve is faulty and so on.
1: SMC solenoid valve after prolonged use valve seals prone to wear, stem and seat damage phenomenon, strict closure, core activities to be stuck, circuit failure, etc., then, should replace the seals , stem and seat, or valve replaced. 2: If the SMC solenoid pilot valve inlet and exhaust vent was blocked sludge and other debris, resulting in gas leakage within the valve, the valve moves slowly or does not change to other faults. Can lead to the valve does not change. 3: SMC solenoid valve can not change or change to the slow, usually due to poor lubrication, the spring is stuck or damaged, oil or some other impurities stuck sliding causes. In this regard, you should check the oil mist device is working properly; oil viscosity is appropriate. If necessary, replace the oil, clean the valve sliding parts, or replace the spring and valve. The former three kinds of situations and activities of the pilot valve should be cleaned of sludge and impurities on the core. The circuit fault is generally divided into control solenoid circuit fault and fault types. Inspection, available instruments measure electromagnetic coil voltage, see if reach the rated voltage, if the voltage is too low, should be further examination of the power control circuit and associated limit switch circuit. If the resistance is too large or too small, indicating that the electromagnetic coil is damaged should be replaced. If the rated voltage does not change the valve, you should check the solenoid connector （plug） is loose or contact is not true. Method is to unplug the plug, measure the coil resistance, fault checking circuit before the first valve manual knob should be turned several times, looking at the rated pressure valve is working correctly for commutation, if normal commutation, it is a circuit failure. www.san17.com