Servo-assisted butterfly valve provided with a compression spring to stabilise the limp-home position

摘要

A butterfly valve (1) comprising a valve seat (4), a butterfly body (5) engaging the valve seat (4), a shaft (6) on which the butterfly body (5) is keyed, an electric actuator (3) coupled to the shaft (6), a torsional return spring (23) adapted to rotate the butterfly body (5) towards a closed position, a compression abutment spring (25) adapted to rotate the butterfly body (5) towards an open position, and an abutment body (28) which causes the action of the abutment spring (25) to stop when the butterfly body (5) is in a limp-home position; the abutment spring (25) having a mechanically fixed end (26) connected to the valve body (2) and a mechanically moving end (27) connected to a wheel (17) rigid with the shaft (6) by means of the interposition of a transmission member (31) mounted to slide within a chamber (29) housing the abutment spring (25). <IMAGE>