Improvements in pressure relief valves

摘要

1,048,464. Valves. R. J. V. HARMAND. Feb. 11, 1964 [Feb. 12, 19631, No. 5720/64. Heading F2V. A pressure relief valve 1, Fig. 2, is mounted on a cock by the threaded parts 7, 9 and upon opening the cock gaseous fuel flows into a highpressure chamber 20 via bores 21, 24; fuel escapes from the chamber 20 into an intermediate chamber 31, through spring-opened valve 36 so deflecting a diaphragm 57 which through a lever 47 moves the valve 36 towards its seat 35 so effecting a pressure reduction. This pressure is transmitted through a conduit 60, an orifice 61 to a chamber 63 where it traverses a calibrated jet 82 the bore 81 of a spring closed valve 66 and a spring-opened valve 91 to deflect another diaphragm 115 and through a lever 105 moves the valve 91 towards its seat 94 and opens a further valve 66 to thereby produce a further pressure reduction. The flow to the valve outlet 97 is controlled by valve 66. Both valves 36 and 91 have triangular bearing surfaces 38, 95, the former ensuring the valve 36 is balanced. The spring 65 which is common to valves 91, 66, is adjustable and is matched with the jet 82. The space between the diaphragms is vented to atmosphere. In a modification, the valve 1, Fig. 6, is connected to the fuel bottle or tank 120 by an extension 140. Upon moving a slide valve 162 to the dotted-line position a part 170 opens to the chamber 20, Fig. 2; concomitantly, a rod 150, Fig. 6, is thrust inwardly via a ball 160 to unseat a valve in a body 126, whereby fuel may flow from the tank 120 to the chamber 20. The valve 162 may be operated through a flexible cable. The relief valve may be permanently connected to the tank and be adapted to admit of filling the latter. In another modification, fuel flows into the high-pressure chamber from a bottle via a camactuated valve 183, Fig. 12, opposed to which is a similar valve 184 through which the bottle is filled. A manually-operable rod. 229 may also be provided to prevent more than a given movement of valve 91 towards its seat so that valve 91 imposes little if any pressure reduction of the fuel passing therethrough.