Abstract: A bleed valve assembly which includes a bleed valve seat having a bleed orifice partially defined thereby and a piezoelectric crystal mounted adjacent thereto so that upon bending of the crystal, as by energization thereof, pressure contact is made with an intermediate valve element. The valve element is in turn adapted to move against the bleed valve seat to close the same. When the bleed valve assembly is closed in the manner above described, pressure is permitted to build up in the orifice to modify the position of a main valve with which the bleed valve assembly is utilized. In addition the crystal is beam mounted within a bore in which the valve seat is positioned and essentially in contact with said bore solely at spaced peripheral edge positions thereof.

Abstract: A valve which is normally biased in a first operative position is provided with control means including a first pressure fluid orifice for directing such fluid to a control member for changing the operative position of the valve. The device further includes a housing which communicates with said first orifice and which has a bleed orifice assembly having a second or bleed orifice. The bleed orifice assembly further includes a bleeder valve seat and a piezoelectric crystal mounted adjacent thereto so that upon bending of the crystal, as by energization thereof, pressure contact is made with an intermediate valve element. The valve element is in turn adapted to move against the bleeder valve seat to close the same. When the bleed orifice assembly is closed in the manner above described, pressure is permitted to build up in the first orifice to activate the valve.