Abstract: A distribution member for mixing cocks, having the form of a lamellar skirt of an elastically yielding material cooperating with fluid passage ports, and having a backing of a compressed resilient material which exerts an elastical backing action substantially onto the whole surface of the operatively active portion of the skirt.

Abstract: A small ball valve for chemically active materials is provided which does not require the strength of metal parts and which permits the use of brittle material such as glass or ceramic as well as materials such as fluorocarbon polymers and polytetrafluoroethylene which are resistant to the action of chemically active fluids. A free-floating construction is provided without requiring a stem packing gland and permitting the stem to be integral with the ball. Identical sealing rings are provided with clamping screws which press the sealing rings inward against the ball and outward against the openings in the valve body, the diameter of the valve stem being smaller than the opening in the sealing ring and clamping screw therefor so that the portion of the ball surrounding the valve stem may also float freely under the sealing means with the seal around the ball stem being against the ball itself instead of against the valve stem.

Abstract: External leakage around the actuator-stem of a plug valve is prevented by the application of forces to the lower surface of the valving member whereby to normally advance and maintain sealing surfaces on the upper end of the valving member against and in sealing relationship with a diaphragm.

Abstract: A ball valve having a seating ring held in a recess in the valve bore by threaded portions of the ring and bore such that, when the ring is in position, the threaded portion on it has passed right through the threaded portion of the bore, there being a radial expansion gap between part of the ring and the recess.