GB820904A - Improvements relating to valves for the control of fluids - Google Patents

Abstract

820,904. Valves. GENERAL GAS LIGHT CO. Feb. 25, 1957 [March 12, 1956], No. 6217/57. Class 135. In a valve comprising a housing having at least one valve chamber across which extends a flexible diaphragm formed with a valve member sealingly engageable with a seat at the end of a passage extending from the chamber to control communication between a port connected to the passage and a port connected to the chamber, the diaphragm has openings therethrough whereby fluid pressure within the chamber acts on both sides of the diaphragm and is flexed by actuating means movable axially of the passage. As shown, the valve comprises a housing 2, Fig. 1, having first, second and third ports 14, 17, 16, Fig. 2, communicating respectively with valve chambers 4, 9 and an interconnecting passage 21 formed at its ends with valve seats 34, 32 engageable with bosses 27, 33 of diaphragms 6, 11 stretched across the chambers 4, 9 and interconnected by a rod 37. The rod 37 is formed with an enlarged head 43 providing a shoulder 47 against which pressure fluid passing through holes in the diaphragm 11 may act. The head 43 has a pin-and-slot connection 54, 56 with a spring-loaded button 51 which may be operated by a hand lever 52, pedal, electrically or by fluid pressure. With port 14 an inlet, port 17 an exhaust and port 16 connected to apparatus to be operated and the lever 52 in its operative position shown pressure fluid passes from the port 14 through the port 16 to the apparatus. On rotation of the lever 52 so that its tip 58 is disengaged from the button 51, pressure fluid passing through holes 26 in the left-hand diaphragm 6 acts on the larger left side thereo to seat the boss 27 and unseat the boss 33 so that the apparatus is connected to exhaust. With port 17 an inlet, port 14 an exhaust and port 16 as before, connected to the apparatus and the lever 52 in its operative position, the apparatus is connected to exhaust. On release of the lever the pressure fluid passing through the holes in the diaphragm 11 acts on the shoulder 47 to unseat the boss 33 and seat the boss 27 so that the apparatus is connected to the supply of pressure fluid. In another embodiment, a housing 70, Fig. 4, having an inlet port 17 and an outlet port 16 is closed by a cover 73a which clamps a diaphragm 78 having a boss 76 against the housing. Pressure fluid from the inlet 17 passing through holes in the diaphragm 78 acts on the surface 81 to hold the boss 76 on its seat 79. A step 82 on the actuating rod 80 may be formed to assist in holding the valve closed. This step 82 coacts with a recess 83 in the cover 73a when the valve is open to reduce the area subjected to pressure.