A center biased actuator having an outer cylinder, a slave cylinder linearly transposed within the outer cylinder, a rod assembly with a piston linearly transposed within the slave cylinder and a rod extending from the outer cylinder, one or more first dynamic seals arranged to act on a sidewall of the rod to inhibit hydraulic fluid leaking from the outer cylinder, one or more second dynamic seals arranged to act on a sidewall of the slave cylinder or an inner surface of the outer cylinder to inhibit hydraulic fluid leaking from the outer cylinder, and a gas chamber comprising a sealed expandable chamber containing gas. The expandable chamber is arranged to act on hydraulic fluid within the center biased actuator to bias the center biased actuator to assume an intermediate condition which lies between a compressed condition and an extended condition.

An accumulator designed to damp the pressure waves of the hydraulic shocks originating in a downstream section of a duct is arranged inside the duct, with the opening of the accumulator pointing downstream. This results in excellent absorption of the pressure wave and protection of the circuit from possible accumulations of air, water or ice, there being no areas where the flow stagnates. Immersing the accumulator in the flow also makes it possible to ensure that the equipment is protected in the event of a fire.

An edge-welded bellows, including a plurality of diaphragms and a guide part for guiding on the outer surface of a rod extending through an inner through-opening of the bellows or for guiding on the inner surface of a tube surrounding the bellows. The guide part has a retaining fin, which, at the edge thereof, lies between the edges of adjacent diaphragms and is welded thereto, and a guide sleeve, which surrounds the longitudinal central axis and has a guide surface for guiding the bellows on the outer surface of the rod or the inner surface of the tube. The guide sleeve has a wall thickness that is more than three times that of the retaining fin. The guide sleeve has a step having a contact surface. The retaining fin lies, in a region adjoining the edge thereof, on the contact surface and is form-fittingly secured against being lifted off from the contact surface.

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.

A bellows accumulator, consisting of at least one accumulator housing (2) and having a separating bellows (20) which is movably arranged in the accumulator housing (2) and has a plurality of bellows folds and separates two media spaces (8, 22) from one another, wherein the stationary open end of said separating bellows (20) is fixed to the accumulator housing (2) by means of a securing device (24) and wherein said separating bellows (20) has at its movable other end a closure part (36) having a guide device (40) by means of which the closure part (36) is guided in the accumulator housing (2), is characterized in that the closure part (36) has, in addition to the guide device (40), a sealing device which, at least in the one extended end position of the separating bellows (20), separates a fluid space (8), in which the bellows folds are arranged in the accumulator housing (2), from a fluid port (12) in the accumulator housing (2) and, at least in some of the other working positions, releases this fluid connection.

A bellows accumulator, consisting of at least two housing parts (4, 6) which form an accumulator housing (2), and having a separating bellows (20), which is movably arranged in the accumulator housing (2) and separates two media spaces (8, 22) from each other and is at least on its one free end fixed to a securing device (24) in the accumulator housing (2), wherein said securing device (24) is welded to the adjacently arranged housing parts (4, 6), is characterized in that the adjacently arranged housing parts (4, 6) comprise at least in part titanium materials, in that the securing device (24) consists of at least two interconnected components (26, 30), at least one (26) of which comprises at least in part titanium materials and is welded to the adjacently arranged housing parts (4, 6), and in that the respective other component (30), consisting of a different metal material, is used for securing the separating bellows (20) to the securing device (24).

An accumulator assembly for providing hydraulic fluid to an actuator. That assembly includes an accumulator for containing a supply of hydraulic fluid, the accumulator having an exit port via which hydraulic fluid can flow, in use, to the actuator. The assembly also includes a coupling comprising a first coupling part configured to be located at an inlet port of the actuator and a second coupling part arranged at the exit port of the accumulator. The first and second coupling parts are configured to matingly engage to form an open passage for flow of the fluid-between the accumulator and the actuator, and to close the first coupling part when the first second coupling parts are not engaged, so as to prevent flow from the actuator and to prevent air and pollution ingress the actuator.

An edge-welded bellows, including a plurality of diaphragms and a guide part for guiding on the outer surface of a rod extending through an inner through-opening of the bellows or for guiding on the inner surface of a tube surrounding the bellows. The guide part has a retaining fin, which, at the edge thereof, lies between the edges of adjacent diaphragms and is welded thereto, and a guide sleeve, which surrounds the longitudinal central axis and has a guide surface for guiding the bellows on the outer surface of the rod or the inner surface of the tube. The guide sleeve has a wall thickness that is more than three times that of the retaining fin. The guide sleeve has a step having a contact surface. The retaining fin lies, in a region adjoining the edge thereof, on the contact surface and is form-fittingly secured against being lifted off from the contact surface.

A pulsation dampener includes: a housing having in internal cavity; an expandable bellows positioned within the internal cavity of the housing, the expandable bellows having a proximal end, a distal end, and an expandable portion between the proximal and distal ends; a bellows support member coupled to an interior side of the distal end of the expandable bellows and extending longitudinally away from the distal end of the expandable bellows toward the proximal end of the expandable bellows; and a cap fixed with respect to the housing and positioned to support the bellows support member when the expandable bellows is in a longitudinally compressed configuration.

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.