A check valve with improved response time comprises a valve member which has a central portion of a substantially convex shape and a guide portion that surrounds the central portion. The central portion has a central convex curvature extending towards the outlet port of the check valve, in the direction of the fluid flow. The guide portion has a weight to area ratio that is smaller than the weight to area ratio of the central portion. Such a check valve has an overall reduced weight of the valve member allowing a faster response time when the valve switches between its closed and open positions.

A pushrod assembly 5 may include a seal carrier 50 for a spaced seal assembly 60 and/or a seal carrier 70 for a stacked seal assembly 74, the spaced seal assembly including first and second annular seals 61, 62 separated by a spacer 63 to isolate between the seals a vented region 28 of the pushrod housing 6, the stacked seal assembly including at least two annular seals 80 stacked on the seal carrier. Each seal assembly can be removed and replaced via an access end 52, 72 of the seal carrier after detaching the access end from an adjacent component of the assembly. The seal carriers may be incorporated into a cryogenic pump 2 wherein at least one annular seal is arranged on each seal carrier to seal the pushrod assembly 5 within its housing 6.

A cryogenic pump system for lifting a cryogenic fluid stored in a cryogenic tank includes a first pump assembly and a second pump assembly. The first pump assembly includes a boost pump that is configured to be disposed within the cryogenic tank and pump the cryogenic fluid received from the cryogenic tank. The second pump assembly is configured to receive the cryogenic fluid from the first pump assembly. The second pump assembly includes a housing, a stator, a reciprocating member, and at least one piston. The housing is adapted to store the cryogenic fluid received from the boost pump. The stator is adapted to produce a magnetic field. The reciprocating member is disposed within the housing and is configured to move based on the magnetic field. The piston is configured to be moved by the reciprocating member to direct the cryogenic fluid from the housing out of the cryogenic tank.

A cryogenic pump configured for pressurizing a cryogenic fluid is provided. The cryogenic pump includes a warm end portion adapted to not contact cryogenic fluid during operation of the pump and including one or more driving components. The cryogenic pump includes a cold end portion adapted to contact cryogenic fluid during operation of the pump and including a pump inlet and a pump outlet. An insulating arrangement including an insulator plate is arranged between the warm end portion and the cold end portion and defines a first air gap between the cold end portion and the insulator plate.

An exemplary system includes a first electric motor and a second electric motor, which are coupled mechanically to one another via a common string of the system. The string has a torsional natural oscillation at a natural frequency. A first oscillating torque acts on the string by the first electric motor and a second oscillating torque acts on the string by the second electric motor. The second electric motor is arranged with respect to the first electric motor such that the effect of the second oscillating torque on the string results in damping of the excitation of the natural oscillation owing to the first oscillating torque.

An exemplary system includes a first electric motor and a second electric motor, which are coupled mechanically to one another via a common string of the system. The string has a torsional natural oscillation at a natural frequency. A first oscillating torque acts on the string by the first electric motor and a second oscillating torque acts on the string by the second electric motor. The second electric motor is arranged with respect to the first electric motor such that the effect of the second oscillating torque on the string results in damping of the excitation of the natural oscillation owing to the first oscillating torque.

A vaporization device, including a fluid supply containing a vaporizable fluid; a plurality of bubble pumps operative to pump fluid from the fluid supply to outlets of the bubble pumps; and a fluid vaporization heater located adjacent the outlets of the bubble pumps to receive fluid from the bubble pumps.

A plunger pump or plunger motor includes a block accommodating a first cylindrical chamber and a plunger movable in this chamber and a drive shaft connected to this plunger, as well as a second cylindrical chamber and a control valve movable in this second cylindrical chamber. Holes O.sub.3 and O.sub.4 can alternately be brought into communication with the connection for the delivery pipe by the plunger and with a connecting hole for a pressure line. The control valve can establish a communication between the hole O.sub.2 and the connecting hole. The drive shaft is connected to a further plunger which is movable in a third cylindrical chamber in which there is a suction hole or delivery hole. The control valve can alternately establish a communication between the suction hole or delivery hole with a connecting hole for a suction pipe and the connecting hole for the pressure line.

A plunger pump or plunger motor includes a block accommodating a first cylindrical chamber and a plunger movable in this chamber and a drive shaft connected to this plunger, as well as a second cylindrical chamber and a control valve movable in this second cylindrical chamber. Holes O.sub.3 and O.sub.4 can alternately be brought into communication with the connection for the delivery pipe by the plunger and with a connecting hole for a pressure line. The control valve can establish a communication between the hole O.sub.2 and the connecting hole. The drive shaft is connected to a further plunger which is movable in a third cylindrical chamber in which there is a suction hole or delivery hole. The control valve can alternately establish a communication between the suction hole or delivery hole with a connecting hole for a suction pipe and the connecting hole for the pressure line.