The subject matter of this specification can be embodied in, among other things, a fluid valve assembly that includes a first fluid port, a second fluid port, a third fluid port, a valve spool configured to be positioned at a first position, a second position away from the first position, a third position away from the first position opposite the second valve position, the valve spool defining a first fluid duct configured to fluidly connect the first fluid port to the second fluid port in the first valve position, a second fluid duct configured to fluidly connect the first fluid port to the third fluid port in the second valve position, and a third fluid duct configured to fluidly connect the first fluid port to the second fluid port in the third valve position.

A system and method for detecting the functional state of a piloted or direct-operated isolation valve in a hydraulic circuit is presented. In some examples the hydraulic circuit is a steering circuit and the isolation valve provides selective isolation between a hydraulic actuator and one or more metering valves. In some examples, the isolation valve assembly is movable between a first position, in which fluid flow between the metering valve and the actuator is enabled, and a second position, in which fluid flow between the metering valve and the actuator is blocked. When the isolation valve assembly is moved to one of the first and second positions, an inlet port and a pressure sensing port of the isolation valve assembly are placed in fluid communication with each other. When the isolation valve assembly is moved to the other of the first or second position, a second inlet port and the pressure sensing port are placed in fluid communication.

A method of controlling an actuator includes switching a primary solenoid valve to a first mode to fluidically connect a supply pressure source to a control chamber of a pilot valve. A fluid from the supply pressure source is directed through the primary solenoid valve to fill the control chamber of the pilot valve and put the pilot valve in a first position. The first position fluidically connects a second chamber of the actuator to a return pressure source. The actuator includes a cylinder between the first chamber and the second chamber and a rod attached to the cylinder. The fluid from the supply pressure source is directed into the first chamber of the actuator to move the cylinder and the rod in a first direction while the pilot valve is in the first position.

An exemplary valve bank and/or modular control valve having a valve body, a valve member movable in a fluid flow of the valve body to control flow of fluid, and an onboard electronic controller that is operably mounted to the valve bank or valve body. The onboard controller is operably connected to at least one actuator of the valve, which is configured to control movement of the valve member in response to commands from the onboard controller. The onboard controller may provide diagnostics, feedback and/or control of the control valve, such as via inputs from one or more sensors that may be included in the valve. The modular control valve may be used with conventional non-intelligent valve banks to thereby impart smart diagnostics and/or feedback into the valve bank in a plug-and-play manner. A communications interface may be provided in the control valve to interface and communicate with an upper-level PLC controller.

A hydraulic system according to one aspect of the present disclosure includes: control valves interposed between a main pump and hydraulic actuators; and solenoid proportional valves connected to pilot ports of the control valves. Among the solenoid proportional valves, a first solenoid proportional valve and a second solenoid proportional valve are connected to a pair of pilot ports of a particular control valve, respectively. The first solenoid proportional valve and the second solenoid proportional valve are directly connected to an auxiliary pump. The solenoid proportional valves except the first solenoid proportional valve and the second solenoid proportional valve are connected to the auxiliary pump via a switching valve. The switching valve includes a pilot port that is connected, by a switching pilot line, to a first pilot line between the first solenoid proportional valve and the particular control valve.

The subject matter of this specification can be embodied in, among other things, a method that includes controlling, by a first fluid valve, a first fluid flow to a first fluid actuator, actuating, by the first fluid actuator, an output, controlling, by a second fluid valve, a second fluid flow to a second fluid actuator, and actuating, by the second fluid actuator, the output.

There is described a valve island base module (12, 14) with at least one valve module receptacle (25a-25h), which comprises means for the attachment of a plurality of valve modules (18a-18h) each including at least one electrically actuatable valve on the valve island base module (12, 14). In addition, the valve island base module (12, 14) has a fluidic and an electrical valve module connection (36a-36h) for the power supply of the valve modules (18a-18h) with electric current. A power supply line (30) is electrically connected with the electrical valve module connections (36a-36h). By means of a safety interface (26, 28) accessible from outside, the power supply of at least one electrical valve module connection (36a-36h) can selectively be interrupted. In addition, there is described a valve island (10) with at least one valve island base module (12, 14) and at least one valve module (18a-18h).

A valve actuator control system, and a related manifold. The control system includes a pneumatic directional valve operable to move the actuator. The manifold has multiple internal channels and is mountable to the pneumatic directional valve in alternative connections so that one internal channel of the manifold is active and the others are non-active, so that the manifold and pneumatic directional valve can provide operability of the actuator in a plurality of different fail modes.

A safety valve which has two fluidically interconnected safety valves, each of which has a 4/2-way valve function. Each safety valve has a first connecting port and a second connecting port, which are connected to each other in such a way that a fluid flow through the two safety valves, controlled by means of a control valve, to a fluid-actuated drive is prevented if the two safety valves simultaneously adopt a first switching position and such a fluid flow is possible if both valves simultaneously have a second switching state. One safety aspect results from the fact that the above-mentioned fluid flow is also prevented if the two safety valves adopt different switching states.

The present disclosure relates to the field of fluid process systems and discloses a manifold system for fluid delivery. The system comprises a first set of Solenoid Operated Valves (SOVs), a second set of SOVs, a plurality of isolating valves, at least one first shuttle valve, and at least one redundant shuttle valve. Each set of SOVs includes at least two SOVs arranged in parallel. The SOVs together form a series-parallel redundancy. Each isolating valve is coupled to an SOV and facilitates hot swapping of that SOV. The redundant shuttle valves provide redundancy to the first shuttle valve and facilitate the flow of a fluid from each of the first set of SOVs to each of the second set of SOVs, thereby promoting system safety and availability.