Pinch Valves

A pinch valve controls flow by mechanically compressing a flexible rubber sleeve (the only wetted component) between two pinch bars or by applying air pressure to an air-operated sleeve. When fully closed, the sleeve is pinched flat - providing complete bore closure with no dead zones, no pockets, and no seats for solids to accumulate. The rubber sleeve self-wipes as it closes, preventing solid build-up. The body and mechanism never contact the process fluid, eliminating corrosion, erosion, and contamination concerns. This makes pinch valves ideal for abrasive slurry, mining tailings, cement, sand, and any fluid carrying suspended solids.

Natural Rubber (NR): softest, most flexible, best abrasion resistance in low-speed slurry; not suitable for oils or oxidising chemicals. EPDM: hot water, steam, and chemical service; good ozone resistance. Neoprene: moderate oil and solvent resistance; general-purpose. Nitrile (NBR): oil, grease, and fuel service. Hypalon (CSPE): excellent chemical and UV resistance; chemical plant service. Viton (FKM): high-temperature and aggressive chemical resistance. For mining and quarry slurry, natural rubber or Neoprene is the most common specification; for chemical or wastewater service, EPDM or Hypalon.

Yes - pinch valves provide smooth, proportional throttling as the sleeve compression increases progressively from fully open to fully closed. The flow characteristic is approximately equal-percentage (flow increases rapidly near the open position and more slowly near closed), making pinch valves suitable for slurry dosing, sand feed control, and process line modulation. For precise modulating control, specify a pneumatic-actuated pinch valve with a positioner to provide repeatable, signal-controlled sleeve compression.

Sleeve life depends on fluid abrasivity, operating pressure, cycle frequency, and sleeve material. In typical mining slurry service (coal or phosphate), natural rubber sleeves last 3–12 months with daily cycling. In lower-abrasivity wastewater or cement service, 1–3 years is achievable. The sleeve can be replaced in the field in under 30 minutes without removing the valve from the pipeline - the body halves separate or the sleeve slides out of the end flanges. Inspect sleeves regularly for cracking, delamination, or wall thinning.