Abstract: A piezoelectrical control element consists of a package comprising a plurality of piezoceramic disks piled onto each other and of intermediately arranged electrodes whereat the package is loosely piled up and mechanically biased and held together by a resilient element.

Abstract: A rotary control valve has a plug in the form of a cup shaped shell mounted on a bracket which is rotatable about an axis orthogonal to and offset from the central axis of a ring seat. This plug is connected to the rotatable actuating bracket by means of a threaded pin and nut so that the plug position can be adjusted with respect to the ring seat. Proper adjustment of the pin and nut allows the plug to be mounted in a fixed position on the bracket and enables the plug to be brought into and out of fluid tight sealing engagement with the ring seat without any bending or deformation taking place in the actuating bracket. The obtaining of this desired tight sealing engagement is aided by displacing the bracket axis from the plug center of curvature in the direction of the position occupied by the plug when in its sealing position, and by making the plug position adjustable along the bracket axis.

Abstract: A rotary control valve has a flexible cup-shaped diaphragm ring seat positioned within a valve chamber that has an annular seating lip portion on inner opposite side portions thereof. An annular outer portion of the diaphragm ring is retained against an annular wall of the chamber by an outer portion of a retaining ring member that is longitudinally adjustable along the inner wall of the chamber. The retaining ring has an inner rigid portion that provides a hard seat surface against which one of the annular lips is compressed into sealing, fluid tight engagement as a spherical plug of the rotary valve is simultaneously brought into sealing fluid tight engagement with the other lip. The fluid acting on an inlet side of the valve is applied by way of openings in an annular intermediate portion of the retaining member to the diaphragm ring in a direction that allows the plug and diaphragm ring to make good fluid tight engagement with one another.