Page 98 - Valve Selection Handbook

Manual Valves 85

Figure 3-45. Rubber-Seated Wedge Gate Valve Without Cavity in Bottom of Valve
Body. {Courtesy of Schmitz & Schulte, D-5093 Burscheid.)

discs with an integral boss in between. The wedge is sufficiently flexible
to find its own orientation. Because the wedge is simple and contains no
separate components that could rattle loose in service, this construction
has become a favored design.
The self-aligning wedge of the valve shown in Figure 3-43 consists of
two identical tapered plates that rock around a separate spacer ring. This
spacer ring may also be used to adjust the wedge assembly for wear. To
keep the plates together, the body has grooves in which the wedge assem-
bly travels.
Rubber lining of the wedge, as in the valves shown in Figure 3-44 and
Figure 3-45, led to the development of new seating concepts in which the
seat seal is achieved in part between the rim of the wedge and the valve
body. In this way, it became possible to avoid altogether the creation of a
pocket at the bottom of the valve body. These valves are therefore capa-
ble of handling fluids carrying solids in suspension, which would other-
wise collect in an open body cavity.
In the case of the valve shown in Figure 3-44, the wedge is provided
with two stirrup-shaped rubber rings that face the rim of the wedge at the