Difference between revisions of "Butterfly valve"

 
(+ cross section)
 
(4 intermediate revisions by 3 users not shown)
Line 1: Line 1:
wats a butterfly valve, and how does its performance realte to a sprinkler valve?
+
[[Image:Wbutterfly.png|frame|Cross-section of butterfly valve; A is barrel, B is seal, C is disk, and D is chamber. Note that sealing geometry is probably inaccurate.]]
 +
[[Image:Butterfly_valve.jpg|frame|A typical butterfly valve]]
 +
A '''Butterfly valve''' is a type of flow control device, used to make a fluid start or stop flowing through a section of pipe.  The [[valve]] is similar in operation to a [[ball valve]].  A flat circular plate is positioned in the center of the pipe.  The plate has a rod through it connected to a handle on the outside of the valve.  Rotating the handle turns the plate either parallel or perpendicular to the flow of water, shutting off the flow.  It is a very robust and reliable design.  However, unlike the ball valve, the plate does not rotate out of the flow of water, so that a [[pressure]] drop is induced in the flow.
 +
 
 +
These valves are typically used in applications where a very large valve is needed, such as pumpkin chucking and dams, and are available on ebay in sizes from roughly 2" to 10+". These are very cheap, with a 4" metal valve often selling for 50-20$ or less. Unfortunately, most butterfly valves use bolts to attach to the pluming system, requiring one to buy a flanged [[adapter]] or use [[flange]]d metal pipe.
 +
 
 +
There are three types of butterfly valve:
 +
# '''Resilient butterfly valve''' which has a  flexible rubber seat. Working pressure up to 1.6 Mpa (232 psi)
 +
# '''High performance butterfly valve''' which is usually double eccentric in design . Working pressure up to 5.0 Mpa (725 psi)
 +
# '''Tricentric butterfly valve''' which is usually with metal seated design. Working pressure up to 10.0 Mpa (1450 psi)
 +
 
 +
== See also ==
 +
* [[Ball valve]]
 +
* [[Gate valve]]
 +
* [[Globe valve]]
 +
 
 +
[[category:valves]]

Latest revision as of 22:47, 27 August 2009

Cross-section of butterfly valve; A is barrel, B is seal, C is disk, and D is chamber. Note that sealing geometry is probably inaccurate.
A typical butterfly valve

A Butterfly valve is a type of flow control device, used to make a fluid start or stop flowing through a section of pipe. The valve is similar in operation to a ball valve. A flat circular plate is positioned in the center of the pipe. The plate has a rod through it connected to a handle on the outside of the valve. Rotating the handle turns the plate either parallel or perpendicular to the flow of water, shutting off the flow. It is a very robust and reliable design. However, unlike the ball valve, the plate does not rotate out of the flow of water, so that a pressure drop is induced in the flow.

These valves are typically used in applications where a very large valve is needed, such as pumpkin chucking and dams, and are available on ebay in sizes from roughly 2" to 10+". These are very cheap, with a 4" metal valve often selling for 50-20$ or less. Unfortunately, most butterfly valves use bolts to attach to the pluming system, requiring one to buy a flanged adapter or use flanged metal pipe.

There are three types of butterfly valve:

  1. Resilient butterfly valve which has a flexible rubber seat. Working pressure up to 1.6 Mpa (232 psi)
  2. High performance butterfly valve which is usually double eccentric in design . Working pressure up to 5.0 Mpa (725 psi)
  3. Tricentric butterfly valve which is usually with metal seated design. Working pressure up to 10.0 Mpa (1450 psi)

See also