Valve open-close indicating apparatus

摘要: A valve open-close indicating apparatus comprises a cylindrical housing having two opposite ends in the axial direction thereof, sleeve arranged for reciprocation between of housing, and elastic member urging from both outer sides with respect to so that is normally situated an intermediate position ends. When piston moves toward one end open valve, pressed against force member, indicates "open." other close force, "closed." ends, restored by means cylindrial without being piston, nothing. The moved as required, either piston.