GB755110A - A valve mechanism for filling and controlling the level of liquid in a tank - Google Patents

Abstract

755,110. Fluid-pressure servomotor control systems. PARKER APPLIANCE CO. Jan. 25,1954 [Jan. 26, 1953], No. 2113/54. Class 135. A valve mechanism for filling and controlling the level of liquid in an aircraft fuel tank comprises a flexible diaphragm 35, Fig. 1, clamped between casing parts 17, 31 and secured to a central dependent portion 33 of the part 31 by a disc 37 having a small hole 45 to form an annular chamber 34 which constantly communicates with the valve inlet 26 through the hole 45, and a bore 46 and duct 47 in the portion 33. The diaphragm 35 is loaded by a spring 44 and carries a valve member 39 which engages a seat 30 and controls the flow of liquid from the inlet 26 into a tank 10 on which the valve is mounted. A float-actuated pilot valve 55 carried by a lever pivoted on a part 50 secured to the upper skin of the tank controls a duct 53 communicating through a pipe 49, the bore 46 and the duct 47 with the chamber 34. Fuel is delivered under pressure to the inlet 26 to open the valve member 39 against the spring 44 to fill the tank. On the fuel in the tank reaching a predetermined level, the pilot valve 55 closes whence pressure builds up in the chamber 34 and the valve 39 rapidly closes. In a modification, two diaphragms are fitted one above the other to form separate pressure chambers each communicating independently with the valve inlet 26 and having an independent floatactuated pilot valve associated therewith. In this case in the event of either of the diaphragms being ruptured, pressure acting on the unruptured diaphragm when the liquid in the tank reaches its predetermined level is effective in closing the valve.