Abstract: A pressure relief valve operable in large transient pressure conditions includes a valve body. A valve seat is movably mounted on the body. A valve disc or pallet is pivotally connected to the valve body by a valve arm and aligned to engage the valve seat in a valve closed position. The valve disc is secured to the valve arm by fasteners and shock absorbers are mounted between the arm and the valve disc. A resilient shock absorber is mounted between the valve seat and the valve body to absorb shock resulting from engagement of the valve disc with the valve seat. Absorption of shock resulting from opening of the valve is accomplished by a shock absorber including a lever mounted on the valve body. At least one shock absorber is mounted on the lever aligned to be engaged by the valve disc upon opening. A second shock absorber may be included to engage the side of the conduit or housing within which the valve is mounted.

Abstract: A magnetic latch for a pressure or vacuum relief valve is disclosed. The pressure or vacuum relief valve includes a cover hingedly connected to a body and a valve seat defined on the body. The latch includes a housing having an open end and connected to either the valve cover or the body. A magnet is mounted within the housing. A striker plate is connected to the other of the valve cover or body in a position to engage the open end of the housing and to be spaced by a gap from the magnet in the valve closed position. The gap between the striker plate and the magnet is adjustable by varying the position of the housing relative to its mounted position. A spring is positioned between the striker plate and the cover or body and biases the striker plate toward the housing in the valve closed position to provide self-alignment and via its adjusting screw to ensure proper engagement of the striker plate with the open end of the housing.