Fluid system and process valve

A fluid system with a safety-oriented valve assembly, which is designed to influence a fluid flow between a fluid source or a control valve and a fluid load and which comprises a valve housing, which has a first fluid connection for a fluidic connection with a fluid connection of the fluid source or the control valve and a second fluid connection for coupling the fluid load as well as a fluid channel between the fluid connections, wherein a first valve, which can be electrically or fluidically switched between a fluid supply position, or open position, and a fluid discharge position, or closed position, is arranged in the fluid channel, wherein an electrically or fluidically actuable second valve, which is a constantly open valve having a vent, which is unthrottled in a first switch position and which is throttled in a second switch position and, thereby, always allows a fluid flow irrespective of the switch position of the second valve, and which can be switched between the first switch position for the fluid channel and the second switch position for the fluid channel, is arranged in the fluid channel, and wherein a sensor for detecting a fluid pressure and for outputting a fluid pressure-dependent sensor signal is arranged in a section of the fluid channel between the first valve and the second valve, as well as with a controller, which is designed to process the sensor signal and to process control signals for the first valve and the second valve, and

• wherein the controller is designed for carrying out a test operation for the first valve, which can be triggered by an internal and/or external signal, wherein, to carry out the test operation, the controller is configured to switch the first valve between the open position and the closed position, and is further configured to switch the second valve from the first switch position to the second switch position, and is still further configured to compare the sensor signal with a predefinable threshold value.