Diaphragm Valve | Plug Valve

Diaphragm Valve
Diaphragm valve get their name from a flexible disc which comes into contact with a seat at the top of the valve body to form a seal. A diaphragm is a flexible, pressure responsive element that transmits force to open, close or control a valve. Diaphragm valve are related to pinch valve, but use an elastomeric diaphragm, instead of an elastomeric liner in the valve body, to separate the flow stream from the closure element.

Diaphragm valve use a flexible diaphragm connected to a compressor by a stud which is molded into the diaphragm. Instead of pinching the liner closed to provide shut-off, the diaphragm is pushed into contact with the bottom of the valve body to provide shut-off. Manual diaphragm valve are ideal for flow control by offering a variable and precise opening for controlling pressure drop through the valve. The handwheel is turned until the desired amount of media is flowing through the system. For start and stop applications, the handwheel is turned until the compressor either pushes the diaphragm against the bottom of the valve body to stop flow or lifts off the bottom until flow is able to pass through.

Plug Valve
A plug valve is a quarter-turn rotational motion valve that use a tapered or cylindrical plug to stop or start flow. In the open position, the plug-passage is in one line with the inlet and outlet ports of the valve body. If the plug 90° is rotated from the open position, the solid part of the plug blocks the port and stops flow. Plug valve are similar to ball valve in operation