BUTTERFLY VALVE

A short face-to-face valve which has a movable vane, in the center of the flow stream, which rotates 90 degrees as the butterfly valve opens and closes. By rotation of its disc butterfly valve controls the flow. It may be used for on – off applications as well as flow modulating. Connection types may be wafer, lug, flanged, groove end, threaded and butt welded. For components do not differ for different connection types, valves shown below may be taken as reference for all.

TYPES OF BUTTERFLY VALVES

a) Concentric butterfly valve :  

Valve body, stem and obturator are concentric.

b) Double eccentric butterfly valve :       

First eccentricity is between the valve body and obturator and the second eccentricity is between the stem and obturator.

c) Triple eccentric butterfly valve:            

In addition to the double eccentric type, the third eccentricity is the conical shape of the obturator seating face. Therefore obturator only contacts body seating face when closed.

BUTTERFLY VALVE