Abstract: A relief vent assembly for a fuel storage tank includes a vent body defining a chamber to provide a substantially axially smooth and unencumbered path of flow for pressurized fluid to vent out from the tank. Such a path of flow allows the pressurized fluid to remain laminar throughout approximately the entire path through the chamber, maintaining a high flow rate. The vent assembly includes a crossbar that supports the rod of a lid that covers a distal margin of the vent body. The crossbar is disposed substantially at the distal margin of the vent body to prevent any premature turbulent flow of the pressurized fluid, which would slow the flow rate. A widening tapered bore of the chamber increases the flow area and serves to offset the area occupied by the crossbar.

Abstract: A relief vent assembly for a fuel storage tank includes a vent body defining a chamber to provide a substantially axially smooth and unencumbered path of flow for pressurized fluid to vent out from the tank. Such a path of flow allows the pressurized fluid to remain laminar throughout approximately the entire path through the chamber, maintaining a high flow rate. The vent assembly includes a crossbar that supports the rod of a lid that covers a distal margin of the vent body. The crossbar is disposed substantially at the distal margin of the vent body to prevent any premature turbulent flow of the pressurized fluid, which would slow the flow rate. A widening tapered bore of the chamber increases the flow area and serves to offset the area occupied by the crossbar.

Abstract: An overfill prevention valve for mounting on the filling inlet of a liquid storage tank has an elongated, tubular valve body provided with an inlet at one end and one or more outlets in the sidewall thereof. A pressure-actuated piston is moveable between an open position spaced below an annular valve seat between the inlet and outlets and a closed position engaging the valve seat to close the outlet. An orifice in the top of the piston communicates with an actuating chamber on the opposite side of the piston so that a measure of piloting liquid flows into the chamber and out a pilot hole at the bottom of the valve body during normal filling operations. A buoyant float is slidable along a hollow guide tube attached to the bottom of valve body and communicates with the pilot port for closing a discharge hole in the guide tube when the float rises to an upwardly buoyed position due to the liquid in the tank reaching a predetermined maximum level.

Abstract: The limitor includes a tubular valve body that houses a poppet valve axially moveable between opened and closed positions by an external float. The poppet is protected from direct engagement with incoming pressurized liquid by an overhead deflector that diverts incoming liquid radially outwardly into an annular region around the deflector so that the liquid can pass through a port underlying and spaced below the poppet. This prevents premature closing of the valve. Preferably, the limitor is constructed from a main support tube that becomes attached to the tank and a valve subassembly that is threadably joined with the tube and projects down into the interior of the tank during use. Alternative embodiments are disclosed, including drop tube versions, for facilitating initial installation of the limitor on the top wall of a tank.

Abstract: The limitor includes a tubular valve body that houses a poppet valve axially moveable between opened and closed positions by an external float. The poppet is protected from direct engagement with incoming pressurized liquid by an overhead deflector that diverts incoming liquid radially outwardly into an annular region around the deflector so that the liquid can pass through a port underlying and spaced below the poppet. This prevents premature closing of the valve. Preferably, the limitor is constructed from a main support tube that becomes attached to the tank and a valve subassembly that is threadably joined with the tube and projects down into the interior of the tank during use. Alternative embodiments are disclosed, including drop tube versions, for facilitating initial installation of the limitor on the top wall of a tank.

Abstract: The float-controlled shutoff valve has an upright flow passage controlled by a transverse valve spool rotated between open and closed positions by the float in response to changing levels of liquid within the holding tank. The spool has a deep, generally U-shaped, diametrically extending cavity on one side and a single, solid sidewall on the opposite side, the cavity being so formed that it presents a cross-flow inlet approximately one quarter turn away from the passage blocking surface of the sidewall. Hence, when the spool is in its open position during filling, the cavity is vertically flow-aligned with the passage while the blocking sidewall is disposed alongside the passage, and when the spool is in its closed position the blocking sidewall spans the passage above the horizontally disposed cavity to prevent fluid movement past the spool.

Abstract: Improvements in plastic coated, steel core reinforced manhole steps; particular improvements in the drive-in or hammer-in ends of a U-configuration manhole step construction, which improvements involve the provision of uniform outer diameter retainer elements on a uniform outer diameter stem for use in either tapered or cylindrical manhole wall holes or openings; combinations of barb-like retainer elements and cylinder-like retainer elements on the drive-in ends of uniform diameter manhole leg ends adaptable for driving into and securing manhole step legs in either tapered or cylindrical manhole wall holes or openings.

Abstract: Improvements in plastic coated, steel core reinforced manhole steps; particular improvements in the drive-in or hammer-in ends of a U-configuration manhole step construction, which improvements involve providing resilient, barb-like retainer elements in the drive-in ends yet relieving such in particular patterns so as to enable debris and water in the formed holes in the manhole to escape in order to protect the concrete against conveyed impact pressures and further enable more effective sealing and engagement of the manhole step ends with the manhole wall orifices; particular improvements in drive or hammer-in manhole steps of the plastic coated, steel core reinforced type wherein the drive-in ends of the manhole steps are so relieved in the end portions thereof as to obviate and prevent any sealing of the recesses or holes in the manhole proper; improvements in wedge tooth or barb configuration to achieve maximum pullout resistance while retaining pressure and material relief features.

Abstract: Improvements in venting manhole covers for liquid containing vessels, tanks, containers and particularly mobile truck tanks for transporting volatile liquids; improved primary venting means enabling vessel closures to vent under internal pressures; improved spring loaded pressure relief means for tank closures.