An Introduction to Pressure Relief Butterfly Valves
Although there are currently several different kinds of valves that can be used to regulate pressure, pressure relief butterfly valves are the favorite of many due to their effective design.
Pressure relief butterfly valves are flow control devices that are used to regulate the flow of water or some other liquid through a pipe. In this respect it is quite similar to the ball valve. However, instead of using a ball as an anchor, it uses a disc that is inserted into the center of the pipe. A rod is inserted through the disc in order to connect it to the actuator located on the outside of the pipe. What really makes the butterfly control valve different than the ball style is that no matter what position it is in, the flow will create a drop in pressure.
Pressure relief butterfly valves are classified as quarter turn valves, and there are several different types to choose from. The best choice for you will depend on the required level of pressure and the application involved. The most widely used styles include the following:
• Resilient – possesses a flexible, rubber seating and a working pressure of 232psi.
In addition, pressure relief butterfly valves also differ depending on their mounting scheme. The most common design option is the wafer style. These are fairly inexpensive and are designed to keep a seal against pressure from several directions which prevents backflow in systems that are only designed for one flow direction. They use a tightly fitting seal, such as an o-ring or gasket, and a flat face on both sides of the valve.
Another option you have is the lug butterfly control valve. These feature threaded inserts on both sides of the valve’s body which allows you to install them using two separate sets of bolts. It will typically be installed between 2 flanges so either side of the system can be disconnected without the other being disturbed in any way. When this type is used in a dead end piping system it will feature a reduced pressure level. Cast iron butterfly valves also vary when it comes to how they are seated. This can be either double offset (DOST) or triple offset (TOST).
Pressure relief butterfly valves can be used in several different applications. Fire Fighters use them on their hoses which can limit the pressure they create, for example. They are also often used on front and rear suction ports, water pumps, and tanks. Besides simply acting as a regulator device, cast iron butterfly valves may also be used to regulate the flow of water in a pipe, which can actually start and stop the flow as desired. The butterfly control valve is one of the most well known and appreciated designs available, being incredibly effective in its overly simplistic design.
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After a succesful life in trading, importing and exports, Rupert now spends his time writing freelance articles for many well-known publications, as well as various educational institutions. For more of Rupert's articles regarding pressure relief butterfly valves, please visit http://www.pressure-relief-valve.com/