COMBINED PRESSURE RELIEF AND VACUUM RELIEF VALVE

摘要

1377509 Fluid pressure servomotor systems LAMBORGHINI OLEODINAMICA SpA 30 Dec 1971 [30 Dec 1970] 60760/71 Heading G3P [Also in Division F2] A combined pressure relief and vacuum relief valve comprises a main valve member 32 controlling a passage 22 between inlet 4 and outlet 5, and a pilot valve 29 also controlling communication between the inlet and the outlet and to the chamber 34 formed by the valve housing and valve member 32. Should the pressure in inlet 4 rise above a predetermined value, the pilot valve opens to admit pressure fluid to chamber 34 which opens the main valve member against a spring 47. Should the pressure in inlet 4 drop below atmospheric pressure, the force on the main valve member by virtue of the pressure in chamber 34 is sufficient to overcome the combined effect of the spring 47 and the reduced inlet pressure acting on the valve member 32.