SV22/37-※ Solenoid Series is the Solenoid which is connected by screw thread. The way of its working has three types: constant open, constant close, double direction. lt's suitable for ∮6-22 inserting valves. The voltage can be 24VDC,12VDC,9VDC, or 220VAC,50-60Hz. It also can be designed according to different electrical source of the customers. Among them, SV22-QF is for Air Valves.