To provide an inexpensive pilot check valve with an operation detection function capable of maintaining performance of a check valve element, achieving high positional precision, preventing reduction of position detection performance, and allowing simple handling.
The check valve element 20a is slidably provided in a valve main body 11. The check valve element 20a displaced by operation of pressure fluid communicates and shuts off fluid passages 12 and 14, 13 and 15. A rod 37a provided in the inside of the check valve element 20a is supported on a case 31a attached to the valve main body 11. A step part 38a for detection is provided on the rod 37a, and a contact 40a is inserted into a small diameter part in which the step part 38a for detection is formed. A ring 44a is screw-fitted into an electrically conductive rod 61a connected with a connector 55a. The contact 40a is engaged with a side wall face of the ring 44a by a spring 41a.
|WO/2009/012020||FLAPPER MOUNTED EQUALIZER VALVE FOR SUBSURFACE SAFETY VALVES|
|JP3933420||VENTING VALVE OF HOUSING BAG|