Page 143 - Valve Selection Handbook

130 Valve Selection Handbook

PINCH VALVES

Pinch valves are flex-body valves consisting of a flexible tube that is
pinched either mechanically, as in the valves shown in Figure 3-88 through
Figure 3-90, or by the application of a fluid pressure to the outside of the
valve body, as in the valves shown in Figure 3-91 and Figure 3-92.
One of the principal advantages of this design concept is that the flow
passage is straight without crevices and moving parts. The soft valve
body also has the ability to seal around trapped solids. Pinch valves are
therefore suitable for handling slurries and solids that would clog in
obstructed flow passages, and for the sanitary handling of foodstuffs and
Pharmaceuticals. Depending on the construction material used for the
valve body, pinch valves will also handle severely abrasive fluids and
most corrosive fluids.
Open and Enclosed Pinch Valves

Mechanically pinched valves may be of the open type, as in the valve
shown in Figure 3-88, or of the enclosed type, as in the valves shown in
Figure 3-89 and Figure 3-90.

Figure 3-88. Pinch Valve, Open Construction. (Courtesy of Flexible Valve Corporation.)