Pinch Valve

Pinch valves are flow control components used in industrial piping systems, particularly in applications involving slurries, abrasive fluids, and corrosive chemicals, where conventional valves may wear or clog. They operate by compressing a flexible sleeve to restrict or stop flow, ensuring that the media only contacts the sleeve, thereby isolating the valve body from corrosive or abrasive substances. This design simplifies maintenance and extends service life in demanding environments.

Pinch valves are specified by nominal bore size, pressure rating, and sleeve material, which must be compatible with the process media. Common size ranges for industrial pinch valves are DN 15 to DN 600 (per ISO 5752), with typical working pressures of PN 1.0 to 1.6 MPa (per EN 558). Operating temperature ranges depend on sleeve material; for example, standard elastomers may handle -20°C to +80°C, while PTFE-lined sleeves can extend the range. Sleeve materials on file include natural rubber (NR), EPDM, nitrile (NBR), and PTFE-lined EPDM. Body materials include cast iron (GG25), aluminum (AlSi7Mg), stainless steel (CF8M), and PVC-U, affecting weight, corrosion resistance, and cost.

Flow coefficients (Kv) range from 2.5 to 1200 m³/h for DN15 to DN600 at full open. Leakage rates can achieve bubble-tight shut-off (Class VI per ISO 5208). Actuation options include manual, pneumatic, electric, and hydraulic. End connections include flanged, wafer, threaded, and clamp, with face-to-face dimensions per EN 558. Sleeve wall thickness typically ranges from 3 to 12 mm, and vacuum service up to -0.08 MPa is possible with reinforced sleeves or support rings. Control accuracy for proportional control with a positioner is typically ±2-5% of span. Sleeve replacement time is typically 10-30 minutes, reducing downtime.

Relevant standards for procurement and verification include ISO 5752, EN 558, GB/T 12221, DIN 3352, and ANSI B16.10. These standards serve as references for dimensions and testing, but do not imply certification of any specific product. Always verify model-specific values and standards with the legal manufacturer or supplier before selection.

A pinch valve operates by applying external pressure to a flexible sleeve, typically using a pneumatic, hydraulic, or mechanical mechanism. When the sleeve is compressed, it collapses to restrict or stop flow; when pressure is released, the sleeve returns to its open shape due to its elasticity. This design ensures that the media only contacts the sleeve, isolating the valve body from corrosive or abrasive substances. The sleeve acts as the only wetted part, simplifying maintenance and reducing the risk of contamination.