Introduction to Butterfly Valves
Butterfly valve is used in fluid flow systems to regulate fluid
flow. The operation of this valve is similar to that of “ball valve” which used
for quick shut off.
Butterfly
valve consists of a disc which is positioned at the center of a pipe. A rod
passes through the disc is connected to an actuator on the outside of the
valve. The disc can be turned either parallel or perpendicular to the flow by
rotating the actuator and thus regulate the flow. The valve can be fully open
or close by rotating the disc quarter turn, hence it is classified as
quarter-turn valve.
Butterfly valves
are generally favored because of its lightweight and low cost. Butterfly
valves are commonly used in the pharmaceutical, chemical, and food industries to
interrupt product flow with in the process. Butterfly valves replaced ball
valves in the petroleum industry due to its low cost and waste of install action.
Advantages of Butterfly
Valves:
1. They are small and
Operate (i.e. open & closed) very quickly.
2. They are quite
reliable & require less maintain ace.
3. Butterfly valves are
easy and fast to open.
4. Butterfly valves are relatively inexpensive to build.
5. Butterfly valves have less space requirements.
6. Butterfly Valves are generally associated with reduced
maintenance.
Disadvantages of
Butterfly Valves:
One disadvantage of
butterfly valves is that some portion of the disc is always presented to the
flow, even when fully opened. The use of a butterfly valve therefore always
results in a pressure switch across the valve, regardless of the setting.
How a Butterfly Valves
is Operated:
Butterfly valves can
be configured to operate manually, electronically or pneumatically. Pneumatic
valves operate most rapidly. Electronic valves require a signal to the gearbox
to open or close, while pneumatic valves can be either single or double actuated.
Butterfly valves operate
like other quarter turn valves. Understanding the way, a basic butterfly valve
works is pretty simple. It can help you to learn more about the components of
valves.
Butterfly Valve Applications
Butterfly
valves can be used across a wide range of applications. They perform well in
large volume water applications and slurry applications. The following are some
typical applications of Butterfly valves:
- Cooling water, air,
gases, fire protection etc.
- Slurry and similar
services
- Vacuum service
- High-pressure and
high-temperature water and steam services
- Compressed
Air or Gas Applications