Combination thermal or pressure activated relief valve

摘要

A combination thermal or pressure activated relief valve is disclosed. The valve includes a housing having an inlet and an outlet formed therein. The inlet is adapted to be attached to a pressure source while the outlet is in communication with an area having a lower pressure value than said pressure source. An insert is secured in the outlet and includes a stem having a first passage formed therethrough and a helical groove formed about its outer periphery. The groove cooperates with the housing to form a helical passageway between the inlet and the outlet. A fusible material is inserted into the helical passageway and normally blocks fluid flow therethrough and is fusible at a selected temperature to permit fluid flow therethrough. A second member is secured to the insert and has a passage formed therethrough which communicates with the first passage formed in the insert. A pressure responsive lamina is positioned across the passage for normally blocking fluid flow therethrough. The lamina is rupturable in response to a selected pressure arising at the pressure source so as to permit pressurized fluid to be released to the lower pressure area.