A control valve assembly for indirect pneumatic control and method for controlling a working fluid pressure, which enable precise, sensitive and speed-variable controlling. The assembly includes two valve units, a working fluid inlet, and a control fluid inlet. A working fluid channel connects the working fluid inlet through the two valve units to an outlet. A valve piston arranged within a valve cylinder of the valve units is movable between open and closed positions. A spring element biases the valve piston toward the closed position, and a control pressure chamber applies a control pressure counteracting the spring element's bias. When a control pressure is applied in the first chamber, the first valve piston is moved to the open position. Two opposite valve surfaces form a valve opening opened at varying widths when the valve piston is moved in the valve cylinder because of a changing control pressure, and the working pressure can be finely adjusted corresponding to the valve opening width depending on the control pressure.

A hydraulic assembly with a lubricant output, a control output and a pump which can supply a hydraulic fluid flow to the lubricant output and the control output. A switching valve with structurally predefined hysteresis is arranged between a pump output and the control output of the hydraulic assembly. Depending on the pressure in the branch between the pump output and the control output, the valve can be switched between an open position in which the control output is connected to the pump output, and a blocking position in which the control output is blocked off. The switching valve switches from the open position to the blocking position when the pressure provided by the pump exceeds an upper switching threshold, and returns from the blocking position to the open position when the pressure provided by the pump falls below a lower switching threshold. A clutch can be switched by means of such a hydraulic assembly, and a method for actuating the clutch.

A safety module for a process valve and a system comprising a safety module and a process valve are provided. The safety module comprises at least a first interface complementary to a first connection interface of a drive module of the process valve and a second interface complementary to a second connection interface of a process valve actuator of the process valve, such that the safety module can be retrofitted in the process valve. The safety module further comprises at least one safety valve and fluid lines provided for fluidically coupling the safety valve to the drive module and the process valve actuator of the process valve. The at least one safety valve of the safety module is configured for forced venting of the process valve in a safety case.

An electropneumatic control system for a pneumatic drive and electropneumatic position controller for the system, wherein a volume flow booster having a bypass valve is downstream of the position controller to increase the air capacity, where the pneumatic drive is run in a new operating mode multiple times at maximum air capacity in a first direction to support an operator in adjusting the bypass valve, and where upon exceeding a specified position, the air capacity is set to zero, an overshoot value of the pneumatic drive is determined and output for the operator on a display such that by varying adjustment of the bypass valve, the operator can find and set an adjustment of the valve having low overshoot such that with an adjustment found in such a manner, the transition behavior of the control system can be significantly improved without additional effort.

An electropneumatic control system for a pneumatic drive and electropneumatic position controller for the system, wherein a volume flow booster having a bypass valve is downstream of the position controller to increase the air capacity, where the pneumatic drive is run in a new operating mode multiple times at maximum air capacity in a first direction to support an operator in adjusting the bypass valve, and where upon exceeding a specified position, the air capacity is set to zero, an overshoot value of the pneumatic drive is determined and output for the operator on a display such that by varying adjustment of the bypass valve, the operator can find and set an adjustment of the valve having low overshoot such that with an adjustment found in such a manner, the transition behavior of the control system can be significantly improved without additional effort.

[Solution] A pilot check valve includes a first body that has input and output ports, a main path 13 that is in communication these ports, and a check valve element that allows a flow of a pressure fluid from the input port toward the output port. The valve element blocks or allows a flow toward the input port side by supply or discharge of a pilot fluid and has a residual pressure exhaust path connected between the main path and an exhaust hole, a seal member that is provided in the exhaust path, and a push rod that moves the check valve element to a position where a flow of a pressure fluid toward the input port side in the main path is allowed and moves the seal member to a position where a flow toward the exhaust hole is allowed.

A hydraulic arrangement for a vehicle transmission includes a hydraulic pump for providing a system pressure for a first hydraulic system circuit and a lubrication pressure for a second hydraulic lubrication circuit. The arrangement also includes a control valve connected between a pump outlet of the pump and the two hydraulic circuits and has two different switching positions. The control valve, depending on the switching position, acts as a hydraulic connection between the pump and the system circuit or between the pump and the lubrication circuit.

A hydraulic arrangement for a vehicle transmission includes a hydraulic pump for providing a system pressure for a first hydraulic system circuit and a lubrication pressure for a second hydraulic lubrication circuit. The arrangement also includes a control valve connected between a pump outlet of the pump and the two hydraulic circuits and has two different switching positions. The control valve, depending on the switching position, acts as a hydraulic connection between the pump and the system circuit or between the pump and the lubrication circuit.

A gangway comprises a fixed platform and a support structure connected to the fixed platform in a manner that allows the support structure to rotate with respect to the fixed platform between a raised stowed position and a lowered deployed position. A self-raising assembly is operative to rotate the support structure from the deployed position to the stowed position. The self-raising assembly includes at least one fluid actuated cylinder connected between the fixed platform and a distal end of the support structure. A raising actuator is usable by an operator to cause operation of the cylinder in a manner that rotates the support structure toward the stowed position.

A gangway comprises a fixed platform and a support structure connected to the fixed platform in a manner that allows the support structure to rotate with respect to the fixed platform between a raised stowed position and a lowered deployed position. A self-raising assembly is operative to rotate the support structure from the deployed position to the stowed position. The self-raising assembly includes at least one fluid actuated cylinder connected between the fixed platform and a distal end of the support structure. A raising actuator is usable by an operator to cause operation of the cylinder in a manner that rotates the support structure toward the stowed position.