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 cap assembly (40) for attachment to an external fixture (44) on a tank (52) of a tanker trailer (50), including: a collar (42) configured to secure the cap assembly to the tank external fixture and defining a collar opening (46) concentrically aligned with an opening (54) of the fixture; a lid (60) that is moveable between a closed position where the lid covers the collar opening and is in sealing engagement with the collar, and an open position where the lid is vertically raised from the collar and pivoted laterally away from the collar opening; and an actuator assembly (72) that is configured to move the lid from the closed position to the open position during a single stroke of the actuator assembly, and which is remotely operable from a location off of the tanker trailer.

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 cap assembly (40) for attachment to an external fixture (44) on a tank (52) of a tanker trailer (50), including: a collar (42) configured to secure the cap assembly to the tank external fixture and defining a collar opening (46) concentrically aligned with an opening (54) of the fixture; a lid (60) that is moveable between a closed position where the lid covers the collar opening and is in sealing engagement with the collar, and an open position where the lid is vertically raised from the collar and pivoted laterally away from the collar opening; and an actuator assembly (72) that is configured to move the lid from the closed position to the open position during a single stroke of the actuator assembly, and which is remotely operable from a location off of the tanker trailer.

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: Pressure relief valve including an annular nut of relatively high thermal conductivity including a first end portion providing an inwardly extending axial cylindrical surface and an internal annular surface extending radially outwardly from the cylindrical surface and including an internally threaded second end portion, and a fusible disc including a cylindrical first end portion provided with frictional enhancement means in frictional engagement with the cylindrical surface to mount the fusible disc frictionally in the annular nut and including an annular second end portion engaging the annular surface to position the fusible disc in the annular nut.

Abstract: Apparatus for venting a container containing a fluid and including a poppet mounted to the bottom of a cap or flap mounted to a housing for being mounted to the container, a fastener for fastening the cap of flap to the housing and which fastener may be a fusible fastener for unfastening the cap or flap and for venting the container to the atmosphere upon heat applied externally to the container reaching a predetermined temperature. The poppet venting the container to the atmosphere upon the pressure in the container reaching a predetermined pressure and the poppet may be a combination poppet for venting the container to the atmosphere upon pressure in the container reaching a predetermined pressure and for venting the container to the atmosphere upon a vacuum in the container reaching a predetermined vacuum.

Abstract: A cap for venting a tank containing a fluid which expands in response to heat applied externally to the tank and which cap includes an outer annular nut, an inner circular central disc, and an intermediate annular ring of polymer-based material which softens in response to the externally applied heat to permit the inner circular central disc to be blown out of the outer annular nut thereby venting the tank and preventing the tank from exploding.

Abstract: A pressure relief vent for a pressure vessel such as an over the road tank trailer including a poppet forced into sealing engagement with a valve seat by a compression spring which maintains the poppet in sealing engagement with the valve seat to a set pressure and which poppet upon the occurrence of pressurized fluid in the trailer tank sufficiently in excess of the set pressure lifts the poppet up off of the valve seat a distance sufficient to permit the over-pressurized fluid to flow out of the vent at the flow rate, the outer peripheral portion of the poppet is provided with outwardly curved and downwardly extending portions which form the escaping over-pressurized fluid into a jet stream which provides reaction force which assists the pressurized fluid in maintaining the poppet lifted off of the valve seat to provide the flow rate and which permits the use of a stiffer and therefore shorter compression spring enabling the pressure relief vent to be shorter in height while maintaining the required flow ra

Abstract: A vacuum breaker for use on a moving tank for allowing atmospheric air to enter the tank to relieve a reduced pressure condition in the tank. The vacuum breaker has a light-weight closure assembly including a closure member of relatively large area. The closure assembly is normally held closed by permanent magnets. The magnets and the light-weight construction of the closure assembly substantially prevent the vacuum breaker from opening due to vibration of the moving tank. However, the vacuum breaker opens readily in response to a relatively slight reduced pressure in the tank because of the large area of the closure member. The permanent magnets are shielded from undesirable proximity of ferrous objects to prevent the magnets from being drained. The vacuum breaker may be opened manually to test for a positive pressure condition in the tank.