GB1219105A - Improvements in or relating to valves - Google Patents

Abstract

1,219,105. Pipe joints; fluid-pressure control valves. WALTER KIDDE CO. Ltd. 13 Nov., 1968 [13 Nov., 1967], No. 51627/67. Headings F2G and F2V. A valve, which is preferably in the form of a discharge head, e.g. of a liquid CO 2 bottle, comprises a valve body 10 having an inlet opening 12 adapted to be connected to a source of high pressure fluid, an outlet opening 21, a passage 24 for the flow therethrough of high pressure fluid from the inlet opening 12 to the outlet opening 21, a valve seating 27 arranged in the passage 24, and a valve part 43 movable longitudinally with respect to the valve seating 27 for engaging the latter to close the passage 24. A piston part 48 is attached to, and adapted to move with, the valve part, the piston part 48 being slidably arranged within a cylinder 32 in the body 10 and the working surface area of the piston 48 being greater than the area of the valve part exposed to the pressure of fluid in the inlet passage. A first conduit 46 connects the cylinder 32 to the inlet passage 12 and a second conduit 40, 41 connects the cylinder to atmosphere, the second conduit 40, 41 having a greater flow cross-section than the first conduit 46. Means 39 for sealing the second conduit and means 62 for rupturing the seal 39, are provided, the arrangement being such that, when the valve body is attached to the source of high pressure fluid, the fluid flows into the inlet passage 12, through the first conduit 46 and into the cylinder 32 outwardly of the piston part 48 to move the valve part 43 into engagement with the seating 27 and thereby prevent flow of fluid to the outlet opening 12. The cylinder 32 is formed in a liner 29 which is held by a nut 31 in the upper end of the body 10 and pivotally carries a handle 62 which can be locked by a pin 61 and which, when free, can be rotated to rupture the head 39 of a break spindle 35. The latter terminates in a conical valve portion 36 which fits into an orifice 34 in the liner 29, the break spindle being screwable into and out of the liner 29 to either shut off, or open, respectively communication between the cylinder space 32 above the piston 48 and a bleed hole 42 leading to atmosphere. The valve 43 and piston 48 are provided with "0" ring seals, the nut 31 is held in position by a lock wire 67, and the outlet opening 12 is closed by a recoil nozzle 22, a conduit 17, communicating with the inlet passage 12 being provided with a safety disc 18 held in position by a recoil nozzle 19. When the valve body 10 is connected to a pressurized bottle and the handle 62 is manipulated the head 39 is ruptured so that air escapes from the cylinder space 32 through the second conduit 40, 41 faster than it enters through the first conduit 46 the latter having a wire 57 extending therethrough to reduce its flow area. The pressure on the piston 48 is thus relieved and the superior pressure on the base of the valve 43 lifts the latter from its seat 27 to provide communication between the inlet 12 and the outlet 21. When it is necessary to provide a controlled amount of discharged gas the handle 62 is dispensed with and the break spindle 35 is rotated to provide an adjustable aperture at the valve seat 34, so that the cylinder space 32 communicates with atmosphere through the bleed hole 42 and the valve 43 lifts off its seat. To charge a CO 2 bottle through the outlet 21 the orifice 34 is opened so that pressure fluid acting upon a stepped portion 55 of the valve 43 is able to lift the latter off its seat 37. Alternatively, the valve 43 may be lifted by injecting fluid pressure beneath the valve piston 48 through an orifice 52. The closing fluid pressure on the upper face of the piston 48 is supplemented by a spring 56.