What is a resilient seated butterfly valve and where is it used?

Butterfly valves have been commonplace in industry since the late 18th century. In fact, James Watt is even said to have used one in his steam engine prototypes. This ubiquitous valve has proven so popular over the decades that several different models have emerged during that time. In this article, PIF explains what resilient seated butterfly valves are and where they’re commonly used.  

A brief introduction to butterfly valves

Butterfly valves offer several advantages over ball, globe, gate and plug valves, particularly for large valve applications. In a nutshell, they deliver cost, space and weight savings and the minimal moving parts mean that maintenance can be kept to a bare minimum. Butterfly valves excel at handling large flows of liquids or gases at relatively low pressures, as well as with slurries or liquids containing suspended solids.

Based on the principle of a pipe damper, a butterfly valve’s flow control element is a disc that is approximately the same diameter as the inside diameter of the adjoining pipe. This disc rotates on a vertical or horizontal axis. When it is parallel to the piping the valve is fully opened, while in the perpendicular position it’s shut. Handle-locking devices enable intermediate positions to be achieved for throttling purposes.

Flow is stopped when the valve disc seals against a seat on the inside diameter of the valve body. Many butterfly valves feature an elastomeric seat, whilst others opt for a seal ring arrangement. There are several types of butterfly available on the market today, which you can learn about here. One of the most common designs is the resilient seated butterfly valve.

What is a resilient seated butterfly valve?

Resilient seated butterfly valves (also known as concentric butterfly valves) are the most basic form of the butterfly valve. The stem is centred in the middle of the valve disc, exerting a high degree of contact with the rubber seat to effect a seal. Resilient seated butterfly valves offer positive shut-off and are capable of handling higher pressures. Seats are generally attached to the body either as dovetail joint seats, cartridge seats or bonded seats.

Where are resilient seated butterfly valves used?

Resilient seated butterfly valves are suitable for a wide range of applications, ranging from sanitary service through to those involving mildly corrosive or toxic media. The following are common industrial applications:

• Food and beverage
• Power and utilities
• Compressed air, gas and desulphurisation plants
• Water and waste effluent treatment plants
• Paper, textiles and sugar
• Transportation and dry bulk handling
• Heating, air conditioning and cooling water circulation
• Pneumatic conveyors and vacuum applications
• Brewing, distilling, and chemical/petrochemical processing
• Construction
• Fuel handling systems
  

For more information about butterfly valves, check out this article about the different types of butterfly valves available and where they’re commonly used.