library #valve

These valves are provided with floating seats that are forced against the disc by the fluid pressure. These halves are interlinked so that they wedge apart when being moved into the fully open or closed positions, but relax in the intermediate position to permit the disc to travel.

Piston valves are closing-down valves in which a piston-shaped closure member intrudes into or withdraws from the seat bore

Globe valves are closing-down valves in which the closure member is moved squarely on and off the seat. It is customary to refer to the closure member as a disc, irrespective of its shape.

Manual valves serve three major functions in fluid-handling systems: stopping and starting flow, controlling flow rate, and diverting flow. Valves for stopping and starting flow are frequently employed also for controlling flow rate, and vice versa, while valves for diverting flow are designed for that single purpose.

Flat metallic gaskets adapt to the irregularities of the flange face by elastic and plastic deformation. To inhibit plastic deformation of the flange face, the yield shear strength of the gasket material must be considerably lower than that of the flange material.