A device for holding a hydraulic cylinder stem in position includes a hydraulic block having series-connected primary and secondary check valves. The latter includes a secondary control stem having a secondary valve body and a seal. A first throttle upstream and a second throttle downstream are closed in a secondary control stem closed position where the seal tightly blocks the secondary check valve, each throttle having a tiny throttle closing gap, preferably 0.1 mm or less. The control stem can move axially into an intermediate position where the throttles remain closed, that is, have a tiny closing gap, but valve body and seal are lifted from a secondary valve seat. The control stem can be moved further into an opening position where the throttles are open, each having an opening gap much larger than the closing gap, and the valve body and seal are lifted from the valve seat.

A valve for applying an emergency brake of a rail vehicle includes a valve housing, an actuation member to be activated by a user, an actuation rod connecting the actuation member with a valve head, wherein the valve head is adapted to abut on a valve seat, a guidance for guiding the actuation rod being provided within the valve housing, and a first spring adapted to push the valve head against the valve seat, wherein the actuation rod includes a first groove and a second groove, and wherein a first following member is provided between the actuation rod and the guidance, being adapted to stably rest in the first groove or the second groove.

A valve assembly, comprising: a valve housing body extending along a longitudinal axis X between a first end and a second end and defining a cylindrical passage therethough from the first to the second end; a fluid inlet at the first end for receiving a pressurized fluid; and a fluid outlet provided in between the first and second end of the housing body; and a piston provided in said cylindrical passage, said piston being axially movable between a first position wherein said fluid outlet is blocked by said piston such that the piston blocks the flow of fluid from the inlet to the outlet, and a second position wherein said outlet is not blocked by said piston and a fluid flow path is formed from the inlet to the outlet.

A valve for a refrigeration system includes a valve body, a guide seat arranged in the valve body, a piston plug that has a metering slot and is axially movable relative to the guide seat to open and close the valve, and an adjustable valve stem that is axially movable to engage the piston plug. The piston plug is movable between a closed position in which the piston plug is seated against the guide seat and engaged with the valve stem to prevent fluid flow through the valve, a metering position in which the piston plug is moved away from the guide seat and engaged with the valve stem to enable a predetermined amount of forward fluid flow through the valve, and a check valve position in which the piston plug is seated against the guide seat to prevent reverse fluid flow through the valve.

A sanitary fitting, more particularly a thermostatic mixing valve, includes a housing, which has a valve seat for receiving a valve and into which at least one feed channel and a discharge channel open, wherein the at least one feed channel is led through a chamber, into which a backflow preventer is inserted and which is closed by a plug. A retaining frame is provided on the plug, which retaining frame protrudes into the chamber and by which retaining frame the backflow preventer is axially fixed.

A hydraulic machine includes an actuator, a tank, a directional control valve disposed between the actuator and the tank, and an adjustable return check valve disposed between the directional control valve and the tank. The directional control valve includes an attachment actuator directional control valve disposed between an attachment actuator of the actuator and the tank and a swing actuator directional control valve disposed between a swing actuator of the actuator and the tank. The adjustable return check valve allows fluid to flow from the attachment actuator directional control valve toward the tank while applying the low back pressure but blocks a flow, and allows fluid to flow from the swing actuator directional control valve toward the tank while applying the high back pressure but blocks a reverse flow.

A shock with an annular base valve flow system is disclosed herein. The system includes a housing, said housing having an inner diameter (ID) and an outer diameter (OD). The system also includes an annular base valve assembly, said annular base valve assembly having an OD smaller than said ID of said housing, such that said annular base valve assembly is insertable into said housing. The annular base valve assembly having an intake pathway axially about a portion of said OD of said base valve assembly and an exhaust pathway axially about another portion of said OD of said base valve assembly.

An assemblable check valve is provided between an inflow pipe and a discharge pipe through which fluid is transferred. The assemblable check valve includes a body part having an inflow region connected to the inflow pipe so that the fluid flows therein, a retention region in which the fluid supplied therein through the inflow region remains, and a discharge region connected to the discharge pipe so that the fluid of the retention region is discharged to the outside therethrough; and an opening/closing part; which is provided inside the body part so as to have a disc assembly for opening/closing the path of the fluid flowing in through the inflow pipe, a stem for providing the movement path of the disc assembly, and a first guide for supporting one side of the stem.

A valve for applying an emergency brake of a rail vehicle includes a valve housing, an actuation member to be activated by a user, an actuation rod connecting the actuation member with a valve head, wherein the valve head is adapted to abut on a valve seat, a guidance for guiding the actuation rod being provided within the valve housing, and a first spring adapted to push the valve head against the valve seat, wherein the actuation rod includes a first groove and a second groove, and wherein a first following member is provided between the actuation rod and the guidance, being adapted to stably rest in the first groove or the second groove.

A valve for hydraulic control of fluid flow rate, comprising: a body provided with an inlet opening, an outlet opening and an actuating opening; a rotating hollow shutter rotatively housed inside said body, said rotating shutter being configured to be crossed by a fluid and to change the passage cross-section inside the valve, in which the rotating shutter comprises at least one first opening rotatively cooperating with at least one mated second eccentric opening, said rotating shutter being configured to be manually actuatable inside the body so that a rotation of said first opening with respect to said second opening is matched by a variation of the fluid passage cross-section in a direction substantially coinciding with the rotation axis.