Abstract: A pressure relief valve (100), having: an upper housing (104) defining a housing internal chamber (112) and comprising at least one window (108) between the upper housing chamber and the atmosphere; a lower housing (106) comprising a housing opening (134); a pallet (170) disposed within the housing internal chamber; and a pair of nested springs (116) disposed within the housing internal chamber and configured to bias the pallet toward the lower housing and thereby form a seal (180) between the housing opening and the housing internal chamber. When the pressure in the housing opening is at a full discharge pressure that is greater than and within fourteen percent of the start-to-discharge pressure, the pair of nested springs is configured to permit the pallet to travel a sufficient distance to expose a flow area of the at least one window that is at least greater than a flow area (138) of the housing opening.

Abstract: A spring capture assembly is provided for securing a compression spring of a spring-biased mechanism, such as a spring-biased pressure relief valve, to permit disassembly of the mechanism without risk of damage or injury associate with rapid resiling of the spring from a compressed state. The assembly includes a tool, a housing having an opening for admitting passage of the tool and capturing the spring at one end, a spring retainer, and a compression spring mounted within the housing and captured at one end by said housing and toward an opposite end by the spring retainer. The tool is adapted for mating with the spring retainer and the housing to compress the spring therebetween. The spring capture assembly may be incorporated into a pressure relief valve for venting pressure and/or vacuum from a pressure vessel. Provided also is a method for disassembling a spring-biased mechanism including a spring capture assembly.

Abstract: A pressure relief valve (100), having: an upper housing (104) defining a housing internal chamber (112) and comprising at least one window (108) between the upper housing chamber and the atmosphere; a lower housing (106) comprising a housing opening (134); a pallet (170) disposed within the housing internal chamber; and a pair of nested springs (116) disposed within the housing internal chamber and configured to bias the pallet toward the lower housing and thereby form a seal (180) between the housing opening and the housing internal chamber. When the pressure in the housing opening is at a full discharge pressure that is greater than and within fourteen percent of the start-to-discharge pressure, the pair of nested springs is configured to permit the pallet to travel a sufficient distance to expose a flow area of the at least one window that is at least greater than a flow area (138) of the housing opening.

Abstract: A spring capture assembly is provided for securing a compression spring of a spring-biased mechanism, such as a spring-biased pressure relief valve, to permit disassembly of the mechanism without risk of damage or injury associate with rapid resiling of the spring from a compressed state. The assembly includes a tool, a housing having an opening for admitting passage of the tool and capturing the spring at one end, a spring retainer, and a compression spring mounted within the housing and captured at one end by said housing and toward an opposite end by the spring retainer. The tool is adapted for mating with the spring retainer and the housing to compress the spring therebetween. The spring capture assembly may be incorporated into a pressure relief valve for venting pressure and/or vacuum from a pressure vessel. Provided also is a method for disassembling a spring-biased mechanism including a spring capture assembly.

Abstract: A valve includes a housing configured to interengage with a container, a first and second poppets axially movable between open and closed positions, a first seal between the first poppet and the housing, a second seal between the first poppet and the second poppet, and first and second resilient members disposed within the housing and urging the first and second poppets toward the closed position.

Abstract: A spring capture assembly is provided for securing a compression spring of a spring-biased mechanism, such as a spring-biased pressure relief valve, to permit disassembly of the mechanism without risk of damage or injury associate with rapid resiling of the spring from a compressed state. The assembly includes a tool, a housing having an opening for admitting passage of the tool and capturing the spring at one end, a spring retainer, and a compression spring mounted within the housing and captured at one end by said housing and toward an opposite end by the spring retainer. The tool is adapted for mating with the spring retainer and the housing to compress the spring therebetween. The spring capture assembly may be incorporated into a pressure relief valve for venting pressure and/or vacuum from a pressure vessel. Provided also is a method for disassembling a spring-biased mechanism including a spring capture assembly.

Abstract: In one embodiment, the valve comprises: (a) a housing configured to interengage with a container, and having at least one axis and at least one aperture; (b) a first poppet axially movably within said housing between a first closed position and a first open position; (c) a second poppet axially movable within said first poppet between a second closed position and a second open position; (d) a first seal between said first poppet and said housing; (e) a second seal between said first poppet and said second poppet; (f) a first resilient member disposed within a first space between said housing and said first poppet, and having a resilient force sufficient to hold said first poppet in said first closed position such that said first poppet urges said first seal against said housing when a pressure differential axially across said first poppet is below a first point, and to allow said first poppet to move in said first direction to said first open position when said fluid pressure differential exceeds said first p