Valves and Sealing.com

Home  :  Submit your News  :  Advertise  :  Site Map  :  Contact Us




You are here: Home >


 
Pinch Valves
 
 
v What is a pinch valve ?
v Where can I find pinch valve suppliers & pinch valve manufacturers?
v Pinch valve videos
v International standards related to pinch valves breitling replica
 
 
What is a pinch valve?
Pinch valves generally consist of a metal casing (enclosed body design) with a flexible elastomer sleeve that forms the fluid path through the valve. Sometimes the pinch valve has no metal casing but only a metal structure and a flexible sleeve (open body design). This flexible sleeve is squeezed or pinched (hence the name pinch valve) to close the valve. The closing of the pinch valve can be done manually or by means of fluid pressure, typically compressed air.
 
manual pinch valveThe manual pinch valve is operated by turning a handwheel to move a stem up and down, fixed to a bar which will squeeze the elastomer against the fixed valve bottom. Some mechanisms consist of two moving metal bars which move simultaneously closer together to squeeze the elastomer sleeve closed. These models can also be automated with pneumatic or electric actuators. A stem packing is not necessary in pinch valves, eliminating a potential leak path.
 
Air operated valves feature a space between body shell and the flexible sleeve. Compressed air is introduced into this chamber and as the pressure builds in the chamber, it constricts the sleeve until it is totally closed. When the valve needs to be opened, the air is vented, thereby allowing the flexible sleeve to return to its original form.
 
pneumatic pinch valveMost other valve types are unable to handle fluids with high concentrations of suspended solids due to the fact that particulate granules tend to jam the metal barriers. For these applications, the pinchvalve offers an excellent solution due to the fact that the flexible sleeve is capable of forming an effective seal around trapped particulates. On the other hand, hard and sharp particles can scratch the sleeve, causing grooves that can eventually lead to tear.
 
The sleeve is produced using various manufacturing procedures. Different manual winding procedures, conventional injection processes or manual packaging in moulds are all manufacturing procedures employed for pinch valve sleeves. The structure of each sleeve decides the cycle frequency involved, as well as the closing and opening characteristics. They come in different elastomer qualities. Therefore, various lasting properties, areas of application and operating temperatures are possible. The quality of the elastomer is crucial to the life time and anti-abrasion characteristics of the pinch valve sleeve.
Typical sleeve materials include NBR (Nitrile, Buna-N), CR (Neoprene),FPM (Viton), EPDM, IIR (Butyle), CSM (Hypalon), and natural rubber.
 
Due to the use of elastomer sleeves, the pinch valve is limited in operating temperature and pressure, depending on the type of elastomer used. Pinch valves cannot be used for vacuum applications as the flexible sleeve will collapse. The elastomer sleeve can be reinforced to increase its operating range.
 
Pinch valves can be used for both shut-off and  throttling services. The effective throttling range is situated between 10% and 95% of the rated flow capacity.
Pinch valves are particularly suitable for solids in bulk or in suspension in air or liquids and are used in the chemical industry (like fertilizer manufacturers), silos/cement sector, pigment and granulate handling, the ceramics/glass/plastics industry, water treatment and waste water treatment, paper & pulp, and in the pharmaceuticals and foodstuffs industry - in short, any industry where abrasive slurries or powders have to be transported through pipelines. Because the fluid is only in contact with the sleeve, and not with the body or operating mechanism, the pinch valve is also often used for corrosive applications or when metal contamination is to be avoided like with food applications.
 
Advantages of pinch valves
·good regulating capability as well as positive shutoff
·minimal friction (pressure drop) and non-clogging
·lightweight and compact (air operated model)
·simple design and easy replacement of the sleeve
·straight through design with high capacity (Cv)
 
Disadvantages of pinch valves
·not for high pressures and temperatures
·not for vacuum applications
·not recommended for gases
 
 
Where can I find pinch valve suppliers & manufacturers?
In our buyers’ Guide/Valve directory you will find many manufacturers and distributors of pinch valves, both worldwide and locally. List of pinch valve suppliers
 
 
 
Pinch valve videos
 
Manual pinch valve
 
 
(Courtesy AKO Armaturen & Separationstechnik GmbH)
 
 
Pneumatic pinch valve
 
(Courtesy AKO Armaturen & Separationstechnik GmbH)
 
 
 
International standards related to pinch valves
ISA-75.10.03, Installed Face-to-face Dimensions for Shell and Tube Flanged Pinch Valves
ISA-75.10.02, Installed Face-to-Face Dimensions for bell ross replica Dual Pinch Flanged Clamp or Pinch Valves (Classes 125 and 150)
ISA 75.10.01 : General Requirements for Clamp or Pinch Valves
 
 
 
Do you want to comment or contribute to this page? Please let us know and contact us.
 
© 2013 - Gope Media Group
 

Newsletter
Subscribe to our Newsletter
Get the latest news in the valves and sealing world straight in your mailbox.
It's easy and it's free.



What are you looking for?












Home | Copyright | Terms of Use | Privacy Policy | Advertise | Site Map | Contact Us
© 2008 - 2013 Gope Media Group, Herent, Belgium - All rights reserved | Created by Creatief