Abstract: A gate valve having a casing, a seat, a gate having a tapered face made in the gate surface in the direction of its movement in the shut-off direction on the side opposite to the side facing toward the seat, a stop provided for engaging the tapered face of the gate, the stop being secured to a rod which is installed transversely of the centerline of a passage of the casing, a sleeve installed in the casing wall for rotation relative to the casing, the inner surface of the sleeve being coaxial with, and surrounding the rod, and the longitudinal centerline of the outer surface of the sleeve being eccentric with respect to the longitudinal axis of the rod.

Abstract: A valve housing has butt pipes for connection to a pipeline for defining therewith a passage for a flow of a fluid being conveyed, preferably of a slurry. A plurality of ribs are provided along the passage on the lower portion of the wall thereof, each rib extending transversely of the passage. Each rib is of a tear-shaped configuration in its section taken along the longitudinal centerline of the passage, the enlarged portion of the rib facing toward the incoming flow of a fluid being conveyed.