The pressure control device shown in FIG. has a high-pressure control valve, shown diagrammatically, with an adjusting drive. In the chromatography of supercritical flow media, the high-pressure control valve serves as a counter pressure control valve which keeps under specific, predeterminable pres

This invention relates to a valve, and more particularly a valve for use in controlling the flow of fluid or semi-fluid medium where the medium is very erosive and can also harden or set to foul the seating of a valve closure member on an associated valve seat.

hile valves of the so-called "butterfly" or "disc" type are widely known and used industrially, they have certain inherent operational limitations which curtail their utility.

Heretofore seat valves of this type have been designed in such a way that in the open position of the valve the frictional forces of the flow as well as the forces of reaction of the flow pressure act in an opening sense, i.e., contrary to the closing force of a spring, for instance.

This invention relates to a valve and, more particularly to a servo operated valve responsive to low force electrical or mechanical input signals.

In a valve having at least one connection P for a pressure medium source and a connection A for the supply of pressure medium to a consuming device, at least one control valve element actuated by a pressure medium to provide a P/A connect/disconnect function and having a movable valve body which coo

A gas valve comprising: a valve body defining an upper valve seat region and a lower valve seat region; a main valve disposed within the valve body, the main valve comprising an upper main plate and a lower main plate; and a control valve coaxially aligned with the main valve, the control valve com

This control valve associated with flush valves in plumbing systems serves as a check valve which under certain conditions prevents the flush valve from operating unintentionally and causing flooding.