Butterfly Valve Pressure

butterfly valve
A valve consisting of a disk rotating on an axis across the diameter of a pipe to regulate the flow, as in the throttles of many engines
A valve consisting of a pair of semicircular plates that are attached to a spindle across a pipe and hinged to allow flow only one way
a valve in a carburetor that consists of a disc that turns and acts as a throttle
A butterfly valve is a valve which can be used for isolating or regulating flow. The closing mechanism takes the form of a disk. Operation is similar to that of a ball valve, which allows for quick shut off.
(Butterfly Valves) A valve consisting of a cylindrical body with a rotating vane to control flow. Tight Shutoff is obtained by an elastomer body liner into which the vane seats.

pressure
the force applied to a unit area of surface; measured in pascals (SI unit) or in dynes (cgs unit); "the compressed gas exerts an increased pressure"
The use of persuasion, influence, or intimidation to make someone do something
a force that compels; "the public brought pressure to bear on the government"
The continuous physical force exerted on or against an object by something in contact with it
The force exerted per unit area
coerce: to cause to do through pressure or necessity, by physical, moral or intellectual means :"She forced him to take a job in the city"; "He squeezed her for information"