Shut-off device for a fluid

摘要

A shutoff device for a fluid with a body having a conduit in which, in use, the fluid flows, a plunger arranged slidingly in a seat formed in the body and provided with an end portion suited to shut off said conduit, and means controlling the movement of the plunger into said seat. The control means comprise at least in particular a member having a hollow shape, made in piezoelectric material and arranged inside a chamber formed in the body and communicating with part of the surface of said plunger. Into the chamber is contained a liquid which is subjected to pressure changes as a consequence of the volume changes induced in the piezoelectric member; said liquid causes the movement of the plunger and consequently the shutoff of the conduit.