Abstract: A liquefied gas unloading and deep evacuation system may more quickly, more efficiently and more completely unload liquefied gases from transport tanks, such as rail cars, into stationary storage tanks or into truck tanks. The system may utilize a two stage compressor, an electric motor, a variable frequency drive, a four way valve, a three way valve, a two way valve, a programmable logic controller based control system and pressure and temperature transmitters. The valving enables deep evacuation of the transport or supply tank to more completely empty the transport tank. The programmable logic controller and variable speed drive may be used to variably control the speed of the two stage compressor so that the system may be running as fast as possible during changes in ambient temperature and/or different stages of offloading the liquefied gases without exceeding the compressor's horsepower limit.

Abstract: One or more techniques and systems are described herein for a compressor technology that may be used to improve operations and outcomes of a compressor. For example, existing compressors with reciprocating pistons utilize a packing system to mitigate leaks. As described herein, a flexible diaphragm may be disposed in a fixed arrangement with the piston rod and the chamber wall of a compressor to improve leakage prevention, and improve overall operations and maintenance of the compressor.

Abstract: Bypass valve assembly that selectively establishes a bypass path for a fluid delivery system and having a body member with a fluid inlet and a bypass fluid outlet, a slidable piston assembly and a slidable cage assembly. Spring members bias the piston assembly and the cage assembly to a closed position to prevent fluid flow from the fluid inlet to the bypass fluid outlet when the delivery pressure is between an upper first threshold pressure value and a lower second threshold pressure value. When the delivery system pressure exceeds the first threshold pressure value, the piston assembly is moved to a first open position that permits fluid flow to the bypass fluid outlet; and when the delivery system pressure is less than the second threshold pressure value, the piston assembly is moved to a second open position to permit fluid flow to the bypass fluid outlet.

Abstract: A delivery system for transferring a delivery fluid from a delivery tank to a customer tank while maintaining a predetermined vessel pressure in the delivery tank, including a pump assembly pumping fluid from the delivery tank and a piping system passing the pumped fluid to the customer tank. A diverter diverts a slip stream portion of the pumped delivery fluid and a heat exchanger assembly selectively heats or cools the slip stream portion for return to the delivery tank. A sensor monitors a selected condition in the delivery tank and a controller responds to the sensor to control the amount and thermal condition of the slip stream returned to the delivery tank.

Abstract: A delivery system for transferring a delivery fluid from a delivery tank to a customer tank while maintaining a predetermined vessel pressure in the delivery tank, including a pump assembly pumping fluid from the delivery tank and a piping system passing the pumped fluid to the customer tank. A diverter diverts a slip stream portion of the pumped delivery fluid and a heat exchanger assembly selectively heats or cools the slip stream portion for return to the delivery tank. A sensor monitors a selected condition in the delivery tank and a controller responds to the sensor to control the amount and thermal condition of the slip stream returned to the delivery tank.

Abstract: A rotating impeller pump having an axial face seal carried on a shaft of the impeller positioned inboard of the impeller has a drive mechanism for the shaft carried seal face commonly driven through a keyway in the shaft which drives the impeller such that both the impeller and shaft seal can be easily removed from the shaft.

Abstract: A sliding vane pump is provided with side plates disposed on opposing sides of the rotor with through holes and grooves in the side plates that cooperate with passageways disposed in the seal head and access head for providing fluid communication to the rotor bearings. As a result, the fluid being pumped is used to lubricate and cool the rotor bearings. Annular grooves disposed in the side plates provide further cooling and lubrication between the side plates and the rotor as well as between the side plates and the seal head and access head. The flow through the pump may be easily reversed by rotating the side plates 180.degree., switching flow through the passageways in the seal head and access head by plugging one passageway and opening another passageway as well as rotating the vanes 180.degree.. The reversal of the flow may be accomplished without disconnecting the companion piping, the prime mover or the electrical wiring.

Abstract: A pressure relief or fluid bypass valve is provided which includes a valve body comprising a first piston, a second piston and a seating land disposed between the first and second pistons. The first piston is directed toward the discharge side of the fluid system; the second piston is disposed on the suction side of the fluid system. The first piston is configured to include an entrance orifice disposed toward the discharge side of the system and at least one exit orifice disposed between the second piston and the entrance orifice. A passageway provides fluid communication between the entrance orifice and the exit orifice. When the valve is in the fully open position, fluid is communicated from the discharge side, through the entrance orifice, through the passageway and out through the exit orifice to the suction side. The valve assembly includes a spring or other biasing means for biasing the valve body into the closed or sealed position.

Abstract: A bearing arrangement for a pump is adapted for controlling thrust loads and limiting undesirable axial movement of components. The pump has a shaft having first and second shaft ends, and the pump may be configured so that the shaft is drivable from one or both of the shaft ends. The first and second shaft ends are respectively supported in a first and second bearing arrangement. Each bearing arrangement includes a radial main bearing having an inner race disposed around the shaft end. The inner race contacts a mounting ring to transfer outwardly axial thrust forces against a thrust bearing assembly. Each bearing arrangement is retained by a bearing cap contacting against an outer side of the thrust bearing assembly. A shim having a selected thickness can be placed between the bearing cap and the housing in order to position the internal pump components in an axially centered position to maintain proper clearances in order to minimize wear.

Abstract: A sliding vane pump having an inside liner with a constant radius pump arc and a constant radius stop arc, connected together by cycloidal arcs. The liner has inlet slots arranged extending around a perimeter of a liner extending into the pump arc for maximum filling of the pumping volume. A herringbone-shaped slot arrangement is provided on a outlet side which increases vane life, increases sealing around the vanes on the outlet side, and decreases liner wear. A relief/fill porting arrangement is provided to pressurize the fluid in the pump chamber, or alternately to relieve pressure from the pump chamber. An improved thrust absorber is described particularly useful for truck mounting of the pump. An asymmetrical inside profile for the liner assists in pump operation by providing a fluid mathematical profile which approaches zero acceleration forces at the point of tangency.