Flowserve Cast Flex Wedge Gate Valve - Manual (Page 9)

Cast Flex Wedge Gate Valves FCD ADENIM0010-02
9
1.0 VALVE DESCRIPTION
(Continued)
1.3 Design Features (Continued)
1.3.2 Disc And Seats
The Anchor/Darling flexible wedge disc is a single cored casting consisting of symmetrical halves joined by a central
boss (Fig. 4). The design of the cored cavity permits uniform flexibility in the disc faces, enhancing sealing. Body seat
rings are set into machined recesses in the body which support and retain the rings (Fig. 5). A seal weld is provided
between the body and the rings. This weld is for sealing only and is not structural. The seat rings are replaceable.
1.3.3 Valve Actuation (Top Works)
A gate valve is operated by moving the disc in and out of the seats with the stem. The necessary thrust for opening or
closing is imparted to the stem by the valve actuator which is supported and restrained by the yoke structure. Five
types of actuators are normally supplied; handwheel, manual gear, electric motor, pneumatic cylinder, and hydraulic
cylinder. The first three impart rotary motion to a stem nut which converts the rotary motion to linear stem movement
via the acme stem threads. The pneumatic and hydraulic cylinder actuators provide direct linear motion to the stem.
Sealing of the bonnet-stem penetration is accomplished by a bolted gland stuffing box containing ring type packing.
Figure 5
Figure 4