Some diaphragm valves are pneumatically actuated, using the force of compressed air on one side of the diaphragm to press it against the dam (on the other side) to shut off flow.
Advantages of Diaphragm Valves
Diaphragm valves can also be used for throttling service.
Its throttling characteristics are essentially those of a quick opening valve because of the large shutoff area along the seat.
A weir-type diaphragm valve is available to control small flows.
Diaphragm valves are particularly suited for the handling of corrosive fluids, fibrous slurries, radioactive fluids, or other fluids that must remain free from contamination.
The operating mechanism of a diaphragm valve is not exposed to the media within the pipeline. Sticky or viscous fluids cannot get into the bonnet to interfere with the operating mechanism.
Many fluids that would clog , corrode, or gum up the working parts of most other types of valves will pass through a diaphragm valve without causing problems. Conversely, lubricants used for the operating mechanism cannot be allowed to contaminate the fluid being handled.
There are no packing glands to maintain and no possibility of stem leakage in valves.
Skype : lmzhbb