GB828893A - Improvements in manual or power operated fluid control valves - Google Patents

Abstract

828,893. Valves. BLACK AUTOMATIC CONTROLS Ltd., and BLACK, A. Dec. 23, 1955 [Dec. 23, 1954], No. 37266/54. Class 135. In a manually or power-operated fluid control valve having a disc-like valve member 8 movable axially into and out of engagement with an annular seating 4, the valve member during the final fraction of its closing travel engages a switch operating member 14 resiliently biased towards the valve member, so as to displace it axially in the direction of travel of the valve member. The member 14 operates a switch 13 controlling an external electric circuit and comprises a plunger anchored to a flexible diaphragm 16 and slidable in a sleeve 15. The switch 13 which may be of the microswitch type may open the ignition circuit of a pilot burner when the valve disc 8, which controls the main gas flow, is unseated, and may simultaneously close an indicator circuit showing the main valve is open. When the valve 8 is closed, a circuit for opening a pilot burner valve is closed. As shown, the valve disc 8 is directly operated against a light spring 12 by a solenoid winding 11 surrounding a non-magnetic tube 10 in which an armature 9 is sealed. In a modification, the diaphragm 16 is exposed to the pressure in the outlet 3 and is held in a normal position by such pressure against a spring. On failure of the gas pressure the plunger 14 rises to operate one set of contacts which operate an alarm circuit indicating a flame failure whilst the valve disc is open. On closure of the valve disc 8, a further set of contacts are operated. The alarm circuit is then broken and a " valve closed indicator is operated. The diaphragm 16 may act against a second spring in the last part of its deflection by the valve disc 8.