A directional poppet valve (10) has valve pistons (16-22) arranged in a valve housing (12) for controlling a plurality of fluid connections (A, B, P, T). The positions of each valve pistons (16-22) in the valve housing (12) can be changed by at least one actuating device. The fluid connections (A, B, P, T) are connected to one another or separated from one another alternately depending on the position of the valve pistons (16-22). The valve pistons (16-22) are arranged inline along at least one axis (R), consecutively and/or at least such as to partially interengage, in the valve housing (12).

A valve assembly including a housing and a first movable member which divides the housing into a control chamber and a main chamber. A second movable member has a first valve part and a second valve part and is movable to engage the first valve part with a corresponding inlet valve part to substantially prevent flow of fluid into the main chamber via an inlet port. The first movable member is provided with an exhaust valve part and is movable to engage the second valve part of the second movable member to substantially prevent flow of pressurized fluid out of the main chamber via an exhaust port. A support part is secured relative to the housing, there being a first seal between the second movable member and the support part and a second seal between the support part and the first movable member.

Apparatus to bias spool valves using supply pressure are disclosed. An example apparatus includes a sleeve of a spool valve, and a spool within the sleeve to control a flow of fluid at a supply pressure through the spool valve as the spool is moved relative to the sleeve in response to a variable input force. A biasing force is to bias the spool opposite the variable input force. The biasing force is to be generated from a biasing pressure of the fluid within a chamber adjacent a biasing end of the spool. The biasing pressure is to be based on the fluid at the supply pressure provided directly to the chamber from a supply of the fluid independent of the flow of the fluid through the spool valve.

A dual-purpose fluid control valve for controlling the flow of fluid to separate systems supplied by the valve. The control valve includes a body having an inlet, a first outlet, and a second outlet. The valve further includes means for controlling a rate of fluid through one outlet based on a fluid demand at the outlet while controlling the rate of fluid flow through the other outlet.

Hard coated spool valves are disclosed. An example spool valve includes a sleeve and a spool to be positioned within the sleeve. The sleeve and the spool are made of a corrosion resistant material. The spool valve includes a wear resistant coating on at least one of the spool or the sleeve.

An open center flushing valve for a hydraulic system including a hydraulic circuit and a fluid flushing system, where the flushing valve has multiple positions that each include a fluid exhaust path through the flushing valve. Any of the flushing valve positions couples the hydraulic circuit to the fluid flushing system through a fluid exhaust path for that position. The flushing valve can include unpowered and powered positions. The hydraulic circuit can have two sides separately coupled to the flushing valve where in a powered position, only one side of the hydraulic circuit is coupled to the fluid flushing system through the flushing valve, and in an unpowered position both sides of the hydraulic circuit are coupled to the fluid flushing system through the flushing valve. In a powered position, the lower pressure side of the hydraulic circuit can be coupled to the fluid flushing system through the flushing valve.

A valve arrangement includes various improvements useable in the context of a fluid additive system, such as a water softener. For example, the valve assembly may include a seal assembly engaged by a reciprocating piston, in which the seal assembly includes a minimal number of parts, is easily assembled, and can be easily inserted in the bore of the valve body without jeopardizing the integrity of the seals. The valve assembly may further include a quick-disconnect system which allows a control head including a valve actuation system and electronic controls to be disconnected from the rest of the valve arrangement with only a partial rotation of the control head. The valve assembly may also include a venturi used for drawing regeneration fluid into the system, and an associated venturi cleaner system which allows a user to unclog the fluid-flow orifice of the venturi without any disassembly of parts of the valve arrangement.

Methods and apparatus to bias spool valves using supply pressure are disclosed. An example apparatus includes a housing of a spool valve, the housing including a first port to receive a fluid at a supply pressure. The example apparatus further includes a spool within the housing. A position of the spool is to be selectively controlled via an input force acting on the spool, the position of the spool to define a path of a flow of the fluid through the spool valve from the first port to a second port of the housing. A biasing force is to bias the spool opposite the input force, the biasing force to be generated from the supply pressure applied to an end of the spool.

The subject matter of this specification can be embodied in, among other things, an apparatus that includes a valve with a valve housing having an axial bore, a first inlet port, a first outlet port, and a piston located within the axial bore and having a first fluid passage and configured to allow reciprocal axial movement of the piston within the axial bore between a first position in which the first fluid passage aligns axially with the first inlet port and the first outlet port to form a first fluidic circuit, and a second position in which the piston blocks at least one of the first inlet port and the first outlet port. The apparatus also includes a lockout assembly configurable to fix the piston into a selected position in a first configuration, and not interfere with reciprocal axial movement of the piston in a second configuration.

A Control unit (2) of a hydraulic unit comprises a control piston (3) slidable arranged in a control cylinder (4) to provide a hydraulic fluid under servo pressure (P.sub.2) at a first outlet (8) of the control unit (2) suitable for the displacement of the hydraulic unit. The servo pressure (P.sub.2) is proportional to a sum of the inner forces of the hydraulic unit and the operational forces act on the control unit (2). The hydraulic fluid provided at the outlet (8) is fed by a charge pressure supply at charge pressure (P.sub.1) at an inlet (7) of the control unit (2). The control piston (3) has a blind bore (5) in the direction of a longitudinal axis (13) of the control unit (2), in which blind bore (5) a pressure relief valve (20) is arranged functioning as a pilot-control unit having a two-sided pressure relief piston (23) arranged in the blind bore (5) and slidable relative to the control piston (3) by means of an actuator (6), such that by displacement of the pressure relief piston (23) reduced charge pressure acts as a hydraulic set pressure (P.sub.4) both on the medial front face (26) and on the distal front face (27) of the pressure relief piston (23) and acts on the front faces (12) of the control piston (3). The control piston (3) is displaceable in the control cylinder (4) by the sum of the pressure forces generated by of the set pressure forces generated by of the set pressure (P.sub.4) and the force of the actuator (6).