Valve Diaphragm
Diaphragm valves are comprised of three parts: body, diaphragm, and bonnet. The diaphragm is pressed against a machined seat in the body to effect closure. The diaphragm valve isolates the bonnet and its working parts from the flow media, which makes the valve desirable for controlling abrasives, corrosives, pure water, etc. Because there are no pockets where dirt can collect, the diaphragm valve is ideal for sanitary applications.
There are two types of diaphragm valves: weir and straightway. Both designs use a wide variety of materials for the body and diaphragm, giving them the capability to handle a broad range of chemicals, abrasive slurries, and other difficult applications.
Both types of diaphragm valve designs provide a bubble-tight shutoff, due to the use of resilient diaphragm materials. Tight shutoff can usually be achieved even where grit, suspended matter, pipe scale, etc., are in the line fluid.
The straightway design has little resistance to flow due to its straight-through flow path. The straightway valve type is generally used for on-off service only.
Weir valves can be used for on-off or for throttling.
Most valves are rated by their ability to withstand pressure. Standard valve pressure ratings have been established to match the ratings given to pipe flanges and fittings by the American National Standards Institute (ANSI).
Most metal valves carry two ratings, one for the ability to handle steam (WSP or working steam pressure) and the other for the ability to handle cold water, oil, or gas (WOG). WSP is usually referred to as the primary rating, and WOG is referred to as the secondary rating. Some valves, such as rubber-seated butterfly valves, use only a WOG rating since they are not generally used on steam.
Manufactures and Suppliers Participating in OPUS
Bell & Gossett - ITT
- ITT, the world's largest manufacturer of pumps and related equipment, offers a broad array of...
(click for details) Embassy Group LTD
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(click for details) F.W. Webb Company
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(click for details) Ferguson
- Ferguson specializes in plumbing and heating, industrial pipe, valves, fittings, underground...
(click for details) Johnson Controls, Inc.
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(click for details) NIBCO INC.
- Founded in Elkhart, Indiana in 1904, NIBCO INC. is a leading provider of a diverse range of flow...
(click for details) Tyco/GRINNELL Mechanical Products
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