Abstract: The redundant valve system 10 of the preferred embodiment includes a first valve unit 12 and a second valve unit 14. The redundant valve system 10 is preferably used to connect a source 16 to a destination 18 and to connect the destination 18 to a reservoir 20. The first valve unit 12 and the second valve unit 14 are coupled to control fluid flow such that fluid flow is allowed in only one of two given directions at any given time, either from the source 16 to the destination 18 or from the destination 18 to the reservoir 20.

Abstract: A monitored fluid control valve is provided having a valve body with an elongated bore. A movable valve element is slidably received in the bore. A switch assembly has an aperture aligned with the bore. The switch assembly includes an electrical switch having a switch arm operatively connected to switch contacts for driving the switch contacts between an open state and a closed state. The switch arm is linked to the movable valve element so that the switch arm is directly driven to match linear reciprocation of the movable valve element.

Abstract: Four poppet valves are mounted in a common machined body which has a single inlet port, a pair of working ports and a pair of exhaust ports. The body interior has four valve ports, two of which connect the inlet port to the two working ports and the other two connecting the working ports with the exhaust ports. The housing also has identically sized guide supports and piston chambers for the poppet valves. These may be chosen either as normally closed or normally open straight way valves in a variety of arrangements. With each arrangement one or more pilot valves, either straight way, three-way or four-way, normally closed or normally open, may be connected to the piston chambers. Thus, the valve system may be arranged to have a four-way function as controlled by a single normally closed three-way pilot valve, operate two independent fluid motors using two three-way pilots, or can be arranged for various other control functions.