Two-stage fluid-pressure reducing valve assembly

869,098. Valves. KOSANGAS A.S. March 23, 1959, No. 9960/59. Class 135. A two-stage pressure-reducing valve consists of a member 10 forming the neck of a gas bottle and embodying a safety valve 24 and a screwed in valve seat 26 for a spring-loaded high-pressure movable valve closure 32. A casing 44 is secured to the member 10 by balls 48 under the control of an axially-movable spring-loaded ring 50, to which casing is fixed a spring-loaded high-pressure diaphragm 62 having a stem 70 extending therethrough and sealed thereto, the lower end of which stem abuts an upward extension 42 of the closure 32 whereby the latter is controlled by the diaphragm 62. The chamber 58 beneath the diaphragm 62, which is connected to the bottle via the seat 26, leads to an outlet 80 through a valve seat 82 with which co-operates a movable valve closure 84; the outlet 80 communicates with a low-pressure chamber 90 beneath a doubly spring-loaded diaphragm 92 secured to the casing 44 and open to atmosphere on its upper surface. A rod 102 extends slidably through the diaphragm 90 so that should the pressure in chamber 90 rise above a given level the diaphragm 92 is lifted against its springs away from a sealing disc 104 whereby gas may flow through the opening for the rod 102; under all other circumstances the rod 102 moves with the diaphragm. Below the disc 104 the rod 102 engages one end of a double spring-wire lever 110 the other end of the lever being connected to the closure 84. The upper end of the rod 102 is slotted 120 and accommodates a pin 122 eccentrically connected to a handle 124 whilst the lower rod end is also slotted 132 to accept a cross-pin 130 attached to the stem 70. In the position shown the pin 122 is spaced from both ends of the slot 120 whereby the rod 102 may move to an extent defined by the slot ends under the control of the diaphragm 92. Upon adjusting the pin 122 to engage the upper end of the slot 120 the rod 102 is lifted, the hinged closure 84 is forced on to its seat and the slot 132 and pin 130 co-operated to cause the diaphragm 62 to be elevated so that the stem 70 leaves the extension 42 whereby the closure 32 is seated by its spring. In operation the diaphragm 62 is actuated by the pressure difference between chambers 58 and 90, the pressure in which the latter is equal to that in the outlet 80; the diaphragm 62 co-operates with the closure 32 to control the pressure in chamber 58 so that it is greater by a constant amount than that in the outlet