Abstract: An eccentric rotary valve housing is provided which can be used in a flangeless construction or a flanged construction. In the flangeless construction, a stud block is recessed to pass around the offset neck portion and is of a size to resist bending and torsion stresses equal to those in the tie bolts. In the flanged construction, a pair of rings are keyed on the housing to cooperate with flanged pipes.

Abstract: The control valve is provided with a double walled cage and a valve plug slidably mounted between the perforated walls of the cage. The control valve serves to reduce gas-generated noise when used for gas service and to control both cavitation and noise when used in liquid service.

Abstract: The valve body is in the form of a segmented ball section and is integrally formed on a rotatable spindle as a cantilevered extension of the spindle. The segmented ball section includes an annular seating surface on one side for seating and sealing engagement with a valve seat in one of the openings of the valve. The opposite surface of the extension is substantially flat to present a limited profile to flow when the valve body is moved out of sealing engagement with the valve seat into an open position. The configuration of the valve body places 20% less ball structure in the flowing stream compared to existing partial ball constructions. The one-sided mounting of the valve body permits complete removal of trim for maintenance or replacement without removal of the valve body from a pipeline. Thus, "out of line" trim changes can be made without having to pull the valve from the pipe.

Abstract: The control valve uses a rotor assembly to control the flow through the valve. The rotor assembly is rotatably mounted within the valve housing and cooperative with a scroll-shaped means in the flow passage which directs the flow of fluid circumferentially around and then through the bladed portion of the rotor assembly. The rotor assembly converts the motion of the fluid therethrough into rotational movement, thereby creating a predictable pressure drop. Means are provided for varying the pressure drop, namely, by axially positioning the rotor assembly relative to the opening formed by the valve seat.

Abstract: The butterfly valve vane is constructed with a main vane portion and a movable servo tab. The servo tab is controlled to open relative to the main vane portion in order to define an auxiliary flow path so that the flow forces acting on the vane create a substantially zero closing moment. The servo tab can be moved by a linkage means integrally connected with the control shaft on which the vane is mounted or can be moved by a separate actuator.

Abstract: The butterfly vane is constructed of two semi-circular parts, each of which pivots about a common longitudinal axis. One part is mounted on a shaft which is connected to a drive while the second part is mounted on a second shaft concentrically of the first shaft. The second shaft is driven in an opposite direction off the first shaft by a suitable transmission. The construction of the split vane and transmission is such that the closing torques are reduced to near zero eliminating the sharp torque gradients in throttling angles greater than 60.degree..