A fluid tank includes polymeric liner comprising an upper wall and a lower wall. The upper wall and the lower wall define a cavity therebetween. A weld joint joins the upper and lower walls together. A method for assembling a fluid tank includes overlapping surfaces of an upper wall and a lower wall to form a liner defining a cavity. The method includes joining the surface of the upper wall and the surface of the lower wall together by welding to form a weld joint between the upper wall and the lower wall. The method can include cooling the weld joint to control warpage of the liner at the weld joint.

A fluid tank includes polymeric liner comprising an upper wall and a lower wall. The upper wall and the lower wall define a cavity therebetween. A weld joint joins the upper and lower walls together. A method for assembling a fluid tank includes overlapping surfaces of an upper wall and a lower wall to form a liner defining a cavity. The method includes joining the surface of the upper wall and the surface of the lower wall together by welding to form a weld joint between the upper wall and the lower wall. The method can include cooling the weld joint to control warpage of the liner at the weld joint.

A system filled with a fluid, designed for underwater applications, in which the interior of a housing and/or tank forms a fluid region which is sealed with respect to the surrounding seawater region, includes at least one hydraulic pressure compensation device, which at least raises the pressure level of the fluid region to the ambient pressure prevailing in the seawater region. The pressure compensation device is constructed in two stages in such a way that at least one store having a flexible wall region and at least one piston store having a displaceable piston are arranged in series. The use of the pressure compensation device to pressurize at least one housing filled with fluid for a hydraulic actuating shaft is also proposed.

A system filled with a fluid, designed for underwater applications, in which the interior of a housing and/or tank forms a fluid region which is sealed with respect to the surrounding seawater region, includes at least one hydraulic pressure compensation device, which at least raises the pressure level of the fluid region to the ambient pressure prevailing in the seawater region. The pressure compensation device is constructed in two stages in such a way that at least one store having a flexible wall region and at least one piston store having a displaceable piston are arranged in series. The use of the pressure compensation device to pressurize at least one housing filled with fluid for a hydraulic actuating shaft is also proposed.

A pulsation dampener for a dispensing system comprising a housing, a diaphragm comprising at least one fluoropolymer layer, the diaphragm dividing the housing into a first compartment and a second compartment, an inlet port and an outlet port each in fluid communication with the first compartment thereby providing a flow path for a liquid to enter the first compartment via the first inlet port and exit the first compartment via the outlet port, and at least one gas disposed within the second compartment, the at least one gas having a kinetic diameter of 0.36 nm or greater, wherein the fluoropolymer of the at least one fluoropolymer layer and the at least one gas are selected such that a gas transmittance rate of the at least one gas through the diaphragm is from 0 mbar*L/second to 1*10.sup.5 mbar*L/second.

A bellows accumulator, in particular a pulsation damper, includes a bellows (3) arranged in an accumulator housing (1) and separating two media chambers (27, 28) from each other. Bellows folds (19) of the bellows can be moved at least partially along the inner wall (35) of the accumulator housing (1). The outside diameter of the bellows folds (19) is selected to be slightly smaller than the associated diameter of the inner wall (35) of the accumulator housing (1) in such a way that spaces (37, 41) are formed, which spaces together form a hydraulic damper for at least one medium.

An accumulator includes a pressure vessel and a partition portion separating an interior space of the pressure vessel into a liquid chamber and a gas chamber so that a volume ratio between the liquid chamber and the gas chamber in the pressure vessel is variable. The pressure vessel includes a first section including a thread portion for fastening the accumulator to a support member and a second section joined to the first section and formed by a single piece including a tool engagement portion capable of engaging with a tool for rotating the accumulator. The first section and the second section are fitted together by mating portions coaxial with the thread portion and the tool engagement portion.

An accumulator includes a pressure vessel including a first section and a second section joined to each other via a joint portion and a partition portion separating an interior space of the pressure vessel into a liquid chamber and a gas chamber so that a volume ratio between the liquid chamber and the gas chamber in the pressure vessel is variable. The first section includes a thread portion for fastening the accumulator to a support member. The second section includes an abutting portion disposed opposite to the thread portion across the joint portion in an axial direction of the thread portion and configured to abut on the support member when the accumulator is fastened to the support member.

An accumulator capable of suppressing collision of a metal bellows with a pressure vessel. A partition unit 300 includes: a tubular metal bellows 310, one end of which is side fixed to a pressure vessel 200 and which expands and contracts according to pressure in a fluid chamber and pressure in a gas chamber; and a bellows cap 320 which is fixed to another end side of the metal bellows 310, the partition unit 300 further including: a seal member 330 which is provided between the bellows cap 320 and a port 221 and seals a working fluid on the side of the fluid chamber via the metal bellows 310 when the metal bellows 310 contracts; and a sliding unit 350 which is fixed to the bellows cap 320 and slides in an expansion/contraction direction of the metal bellows 310 relative to a stay 400.

The present disclosure relates to a variable pressure vessel. The vessel includes a liquid chamber and a gas chamber and a moveable barrier therebetween. The vessel has a volume, a first stroke, and a second stroke. The liquid chamber and the gas chamber each have a variable volume that changes responsive to the first stroke and the second stroke. The gas chamber has an outer wall wherein at least a portion of the outer wall is thermally conductive and allows heat to transfer therethrough. Movement of the moveable barrier between the liquid chamber and the gas chamber causes the volume in the liquid chamber and the volume in the gas chamber to displace each other. The volume in the gas chamber plus the volume in the liquid chamber is generally constant and generally equals the volume in the variable pressure vessel.