A valve of a type for use particularly in animal waterers. A valve body having a passageway extending therethrough has a valve stem disposed in the passageway. The valve stem has an enlarged portion on one end thereof having longitudinal slots therein and a valve head on the other end thereof for cooperation with a valve seat located at one end of the passageway of the valve body. A screen having perforate sides and an imperforate end is connected to the valve body and encompasses the valve head...

A valve comprises a valve member engageable with a valve seat provided in a valve body, an annular seal slidably supported on the valve member or adjacent the valve seat and having an axial end face which is sealing engageable with the valve seat or valve member respectively on engagement of the valve member with the valve seat, the axial end face providing at least some of the sealing between the valve member and valve seat. In use the differential in pressure existing between the upstream side...

Valve mechanism for high-vacuum clean environments, wherein a slot aperture is closed by a gage having a lever. Motion of the gate which covers and uncovers the slot is imparted to the gate by longitudinal movement of the lever. Motion of the gate which seals and unseals the slot is imparted by pivoting movement of the level about a fulcrum near the center of the lever. The pivoting movement is imparted at a time different from that at which the longitudinal movement is imparted, and the pivotin...

A plug valve is disclosed which has a radially outwardly directed projection at the end of the valve stem, the projection being received in a complementary cylindric chamber in the plug of the valve for easy exchange of the plug during maintenance of the valve. The plug is freely rotatable relative to the stem of the valve. In the preferred embodiment, the stem of the valve does not rotate during the opening or closing motion. The invention provides a simplified structure, improves reliability o...

A valve comprises a first relatively fixed valve component assembly surrounding a second valve component assembly which is relatively movable within said first assembly. A seal is provided between the first and second valve component assemblies and a barrier assembly is provided for preventing particulate contaminant material reaching the seal. The barrier assembly comprises first and second barrier elements extending around said second valve component assembly. The first barrier element or elem...

A stepped piston is axially displaceable in the stepped piston valve chamber and has a front face facing the front face of the valve seat and an axially opposite surface formed at the juncture of its piston head portion to its reduced diameter shaft portion. The piston has an axial through-bore that opens to fluid connecting bore in the valve housing while the housing has a second fluid connecting bore. The piston is displaceable in the chamber between an open position permitting substantial flu...

A valve employing a coupling disk to rotate the valve member so that rotative force is applied to the valve member in a direction away from the seat during opening of the valve and/or in a direction toward the seat during closing of the valve. Closing force is provided by a spring in a dome chamber and a gas charge in the dome chamber. A float valve controls fluid entry into the dome chamber to trap the gas charge therein while permitting the introduction of liquid from a balance-closure assist ...

A valve having a first valve body including a first contacting surface, a pressurized fluid supply path opening to the first contacting surface and a pressure-controlled chamber opening to the first contacting surface. A second valve body includes a second contacting surface contacting with the first contacting surface and a valve path whose ends open to the second contact surface, and which connects fluidly the pressurized fluid supply path to the pressure-controlled chamber. A valve is arrange...

A valve of the kind for controlling the flow of fluid from at least two alternative supplies in such a manner that reduction or cessation of one supply automatically causes the valve to switch to another of the alternative supplies comprises a cylinder having a piston slidable therein in a region between a first fluid inlet and a second fluid inlet. The piston has working surfaces of differential area such that equal pressure on both sides of the piston biases the piston to one end of the cylind...

A high-pressure control valve (2) used in chromatography serves as a counter pressure control valve which, in a separating column, is intended to maintain a specific predeterminable pressure. The valve has a valve seat (12) with an outlet channel opening (18) located in its center and a valve body (13) that cooperates with the valve seat. The valve body (13) can be moved with the aid of a piezo transducer, actively in the opening direction and, while being monitored, actively in the closing dire...