Pinch valves are simple devices, but they are specified badly more often than almost any other valve type. Three decisions determine whether the installation works: the size, the sleeve compound, and the actuation air pressure relative to the line pressure. Get those right and the valve performs as intended for a long time.
Decision 1: Size
The bore should be sized for the velocity the line is designed around — not the smallest valve that physically fits. Under-sizing raises velocity, and higher velocity in abrasive service erodes the sleeve faster. In gravity discharge, the bore must also exceed the critical arching dimension for the material, or bridging will occur regardless of how good the valve is.
Decision 2: Sleeve Compound
We supply pinch valve sleeves in two compounds, and the choice is driven by the medium rather than by price:
- Natural rubber
- Food-grade EPDM
We do not offer NBR, silicone, FKM or exotic compounds as standard pinch sleeves, and we will say so rather than promise a compound we cannot support. If your medium attacks both natural rubber and EPDM, that is a signal that a sleeve valve may not be the right technology.
Decision 3: Air Pressure and Line Pressure
A pinch valve must develop enough closing force to overcome the line pressure. This is the requirement most often overlooked. If the plant cannot supply the air pressure the valve needs to seal against its line pressure, the valve will leak — and no amount of specification elsewhere will fix it.
Confirm both numbers before ordering: the maximum line pressure the valve will see, and the minimum air pressure guaranteed available at that location. Compressed air systems often fall well below nominal pressure at the far end of a plant.
Decision 4: Actuation Mode
Mode | Best for | Notes |
Manual handwheel | Fixed settings, infrequent operation, remote sites | No air supply needed; suitable for choke positions |
Pneumatic | Frequent cycling, automation, modulation | Needs a defined air supply; can be positioned proportionally |
Decision 5: Connection Type
The Mistakes That Cause Disappointment
- Under-sizing
- Ignoring the air supply
- Leaving the valve permanently part-closed
- Choosing the sleeve on price
- Assuming any elastomer is available
Service and Consumables
The sleeve is a consumable wear part and should be treated as one: inspect on a schedule, keep a spare per critical line, and store spares in a cool dark place. Our valves carry a 12-month warranty on the valve body; sleeves are excluded, as is normal across the industry.