In a pressure controller for adjusting a pressure in a container connected downstream of the pressure controller and in fluid communication therewith, the pressure controller includes a main fluid duct having a fluid input and a fluid output leading to the container and a control valve for adjusting a fluid pressure at the fluid output, a bypass duct branching off from the main fluid duct downstream of the control valve, configured for venting of the main fluid duct, and a flow cross-section of the bypass duct being smaller than a maximum flow cross-section of the main fluid duct.

A vacuum valve placed between a vacuum vessel and a vacuum pump to adjust a valve opening degree using an operating fluid includes a packing mounted in a recessed groove of a piston. The packing is provided with a contact portion on a radially inner side and a contact portion on a radially outer side, and a slide-contact portion contacting with an inner peripheral surface of a cylinder. A portion between the contact portion and the slide-contact portion has a thin thickness.

A pilot pressure supply solenoid valve (36) is disposed in a flow path connecting an inlet port (16) and a pilot chamber (48), and a pilot pressure discharge solenoid valve (38) is disposed in a flow path through which a pressure fluid in the pilot chamber is discharged to the exterior. A flow path, through which the pressure fluid that has passed through a supply valve (26) is discharged to the exterior, is not provided.

A pressure control device has at least two switching valves (10, 12), a feedback control unit (14), a sensor unit (20), and a voltage supply unit (24), and continuously adjusts hydraulic systems.

A pressure regulator includes an outlet pressure sensor, loading and unloading electromagnetic valves, and a regulator control circuit operatively connected to the loading and unloading electromagnetic valves and configured to pilot the loading and unloading electromagnetic valves to cancel an error signal given by a difference between an inlet signal corresponding to a desired outlet pressure and a feedback signal provided by the outlet pressure sensor. The pressure regulator includes an engaging current analysis circuit to detect and store reference characteristics of the engaging current of the solenoid of the loading electromagnetic valve in a stable inlet pressure condition, monitor the engaging current to detect any variation of its characteristics with respect to the corresponding reference characteristics, and, in the event of variation, provide a pilot modulation signal to at least one of the loading or unloading electromagnetic valves or a pressure variation signal to the regulator control circuit.

A valve assembly having a plurality of fill valves that permit a fluid to flow from a fluid inlet into an interior flow path to increase a pressure of the fluid output from a fluid outlet, and a plurality of dump valves that permit the fluid to flow from the interior flow path to an exhaust to reduce the pressure of the fluid output from the fluid outlet. The valve assembly includes a controller that is configured for receipt of a command signal including a desired pressure of the fluid to be output from the fluid outlet, and is configured for receipt of a signal from a pressure sensor that is indicative of an actual pressure of the fluid output from the fluid outlet, wherein based on a comparison of the command signal with the signal indicative of the actual pressure, the controller is configured to selectively open and close each of the fill valves and each of the dump valves until the actual pressure is equal to the desired pressure.

A pressure regulator includes an outlet pressure sensor, loading and unloading electromagnetic valves, and a regulator control circuit operatively connected to the loading and unloading electromagnetic valves and configured to pilot the loading and unloading electromagnetic valves to cancel an error signal given by a difference between an inlet signal corresponding to a desired outlet pressure and a feedback signal provided by the outlet pressure sensor. The pressure regulator includes an engaging current analysis circuit to detect and store reference characteristics of the engaging current of the solenoid of the loading electromagnetic valve in a stable inlet pressure condition, monitor the engaging current to detect any variation of its characteristics with respect to the corresponding reference characteristics, and, in the event of variation, provide a pilot modulation signal to at least one of the loading or unloading electromagnetic valves or a pressure variation signal to the regulator control circuit.

A system for controlling pressure of a sealed enclosure such as a glove box or containment vessel, including: a first control circuit configured to keep a current pressure value of the sealed enclosure within an operational pressure range, and configured to isolate the sealed enclosure and to transmit a primary alarm signal in event of current pressure value reaching one or other of primary limits of a degradation range; an independent secondary safety circuit separate from the primary circuit, the secondary safety circuit configured to isolate the sealed enclosure and to transmit a secondary alarm signal when the pressure of the sealed enclosure reaches one or other of secondary limits of an alarm range.

In a pressure controller for adjusting a pressure in a container connected downstream of the pressure controller and in fluid communication therewith, the pressure controller includes a main fluid duct having a fluid input and a fluid output leading to the container and a control valve for adjusting a fluid pressure at the fluid output, a bypass duct branching off from the main fluid duct downstream of the control valve, configured for venting of the main fluid duct, and a flow cross-section of the bypass duct being smaller than a maximum flow cross-section of the main fluid duct.

Animal drinking troughs have pressure reducers for reducing the higher pressure of the liquid supply to a low liquid pressure for supplying the animal drinking troughs. For various reasons, it is desired to change the reduced pressure. This takes place by adjustment of the pressure reducers. It is known to undertake such an adjustment with compressed air. This requires a separate compressed air source and a corresponding pipe system. The invention makes provision to adjust the pressure reducer hydraulically by means of the higher pressure of the liquid of the liquid supply. The energy required for adjusting the pressure reducers thereby provides the liquid pressure of the liquid supply. As a result, the pressure reducers according to the invention operate autonomously. A separate energy source for adjusting the pressure reducers is not required.