Abstract: A pressure control system comprises separate conduits for supplying liquefied gas and vapor from a cryogen space defined by a cryogenic storage tank. A first conduit can deliver liquefied gas to a use device through a heater and then a first flow controller. A second conduit can deliver vapor to the use device with flow therethrough controlled by a second flow controller. The first flow controller is not exposed to liquefied gas at cryogenic temperatures because it is located downstream from the heater. For automatic operation a pressure sensor measures pressure inside the cryogen space and the first and second flow controllers are independently operable to maintain the pressure inside the cryogen space within a predetermined range. In a preferred embodiment the liquefied gas is a combustible fuel that is consumed by an internal combustion engine, which is the use device.

Abstract: A pressure control system comprises separate conduits for supplying liquefied gas and vapor from a cryogen space defined by a cryogenic storage tank. A first conduit can deliver liquefied gas to a use device through a heater and then a first flow controller. A second conduit can deliver vapor to the use device with flow therethrough controlled by a second flow controller. The first flow controller is not exposed to liquefied gas at cryogenic temperatures because it is located downstream from the heater. For automatic operation a pressure sensor measures pressure inside the cryogen space and the first and second flow controllers are independently operable to maintain the pressure inside the cryogen space within a predetermined range. In a preferred embodiment the liquefied gas is a combustible fuel that is consumed by an internal combustion engine, which is the use device.

Abstract: A hydraulic drive system comprises a hydraulic actuator comprising a piston reciprocable between two cylinder heads for actuating a machine. A flow switching device reverses the direction of hydraulic fluid flow to and from chambers on opposite sides of the piston. The piston stops at the end of each piston stroke when a shuttle valve associated with the piston opens to allow hydraulic fluid to flow between the chambers cancelling the differential pressure that acts on the piston to cause reciprocal movement. A controller is programmed to determine when the piston reaches the end of each stroke based upon at least one of hydraulic pump speed, hydraulic fluid pressure, or elapsed time, with each of these measured during each stroke. The controller then sends an electronic signal to command the flow switching device to reverse the direction of hydraulic fluid flow.

Abstract: A hydraulic drive system comprises a hydraulic actuator comprising a piston reciprocable between two cylinder heads for actuating a machine. A flow switching device reverses the direction of hydraulic fluid flow to and from chambers on opposite sides of the piston. The piston stops at the end of each piston stroke when a shuttle valve associated with the piston opens to allow hydraulic fluid to flow between the chambers cancelling the differential pressure that acts on the piston to cause reciprocal movement. A controller is programmed to determine when the piston reaches the end of each stroke based upon at least one of hydraulic pump speed, hydraulic fluid pressure, or elapsed time, with each of these measured during each stroke. The controller then sends an electronic signal to command the flow switching device to reverse the direction of hydraulic fluid flow.

Abstract: The apparatus comprises a double walled vacuum insulated vessel defining a cryogen space for holding a cryogenic fluid, a pump assembly comprising a pump with a suction inlet disposed within the cryogen space, and at least one elongated member extending from the pump to a drive unit disposed outside the cryogen space. The elongated member comprises an elongated non-metallic section that has a thermal conductivity that is less than that of a structurally equivalent elongated stainless steel member of the same length. In preferred embodiments, the elongated member can be one or both of a drive shaft or a rigid structural member for supporting the pump and holding it in a fixed relationship to the drive unit. The method employs the apparatus to increase hold times for holding cryogenic fluids by reducing heat leak into the cryogen space.

Abstract: The apparatus comprises a double walled vacuum insulated vessel defining a cryogen space for holding a cryogenic fluid, a pump assembly comprising a pump with a suction inlet disposed within the cryogen space, and at least one elongated member extending from the pump to a drive unit disposed outside the cryogen space. The elongated member comprises an elongated non-metallic section that has a thermal conductivity that is less than that of a structurally equivalent elongated stainless steel member of the same length. In preferred embodiments, the elongated member can be one or both of a drive shaft or a rigid structural member for supporting the pump and holding it in a fixed relationship to the drive unit. The method employs the apparatus to increase hold times for holding cryogenic fluids by reducing heat leak into the cryogen space.

Abstract: A high-pressure fuel system supplies gaseous fuel to an internal combustion engine. Gaseous fuel pressure within the system is at least 17 MPa during normal operation. The system comprises a number of components and conduits and at least one resilient member for sealing at an interface between two components. The resilient member consists essentially of thermoplastic polyurethane. A corresponding method provides sealing between components containing gaseous fluids at pressures that can be above 17 MPa, in which the gaseous fluids routinely undergo rapid reductions in pressure. The method comprises disposing a resilient member, which consists essentially of thermoplastic polyurethane, at an interface between the components. Gas pressure fluctuations can occur during operation of the components or when the high-pressure gas is vented from the components upon shut down of the high-pressure system.

Abstract: In the present method, cold substances are transferred through a nozzle with moving parts. An insulating boot facilitates the method. The present method is generally suited for use in transferring cryogenic substances such as during the refueling of liquid natural gas vehicles. The present method causes an insulating layer to be created between a removable boot and a nozzle separating the ambient environment from the moving parts of the nozzle, restricting the incursion of such moisture from the layer and therefore, from the moving parts to avoid freezing up of the moving parts.

Abstract: This invention relates to an apparatus for pressurizing a fluid and delivering a gas comprising a pump, an accumulator and a heater such that the pump pressurizes a quantity fluid received from a fluid store and delivers that pressurized fluid to an accumulator. The accumulator then delivers a quantity of the pressurized fluid to a heater that, in turn, warms the fluid to a gas within a specified temperature and pressure range to be delivered to the end user as required. The invention further relates to a method of delivering a gas at a desired pressure and temperature wherein a quantity of fluid is received, pressurized and stored as a fluid in an accumulator storage vessel at a desired pressure. The fluid is then delivered from the accumulator to a heater where it is warmed and delivered to the end user as a gas at specified temperature and pressure.

Abstract: The present invention is a cryogenic tank assembly that includes a vessel with a cryogen space capable of storing a cryogenic fluid at an initial pressure. The assembly further includes a pump that has an intake opening so that it can receive a quantity of the cryogenic fluid, pressurize it to a pressure above its storage pressure and deliver it to an accumulator within the cryogen space. The accumulator includes a storage volume to hold the pressurized fluid so that it is available depending on the demands of the end user.

Abstract: A seal assembly for providing sealing between a movable cylindrical body and a housing body comprises separate sealing mechanisms for providing static and dynamic sealing. The seal assembly is associated in fixed relationship with either the cylindrical body or the housing body and provides a static seal with the body it is associated with and a dynamic seal with the body that moves relative to the seal assembly. The static sealing mechanism is temperature-activated so that within the operating temperature range, a metallic member of the static seal mechanism is pressed tightly against the associated body to provide a fluid tight static seal. The temperature-activation is caused by the metallic member having a different thermal expansion coefficient than the associated body. The dynamic seal may employ known dynamic sealing mechanisms such as spring-energized seals, interference fit seals, and/or temperature-activated seals.