Festo VZQA Pinch Valve: Dead-Space-Free Process Valve for Abrasive and Viscous Media | Doskee Automation

VZQA Pinch Valve: A Dead-Space-Free Process Valve for Abrasive and Viscous Media

Conventional ball or globe valves, when handling highly viscous, abrasive, or solid-particle-laden media, tend to trap residue, clog, or wear their sealing surfaces. Festo’s VZQA pinch valve takes a different route: it opens and closes by squeezing a soft tubular shut-off element, so the medium flows only inside the tube — achieving full bore, no dead spaces, and no blockages, fundamentally avoiding the weaknesses of traditional valves on difficult media.

The VZQA handles gases, liquids, granulates and powdery solids, highly viscous fluids, abrasive media, and liquids containing solid particles, and is offered in normally-closed (NC) and normally-open (NO) configurations with modular combination, widely used in food, pharmaceutical, chemical, and bulk-solid handling.

Full Bore, Easy to Clean, Replaceable

A standout advantage of the VZQA is its full-bore passage: low flow resistance, no residue, and no dead spaces, with interior and exterior surfaces that are easy to clean to Clean Design standards. The shut-off element (tube) is designed as a replaceable seal cartridge that swaps out without special tools, with a typical maintenance interval of about 500,000 to 1 million switching cycles. Reversible flow is supported, and food-safe silicone shut-off elements (S1 variant) plus end-position sensing versions are available.

Two Operating Principles and Key Specs

The NC version is closed at rest by spring force; applying operating pressure moves the piston and releases the pinch so medium flows, and removing pressure returns it closed. The NO version applies compressed air directly to the tubular sleeve, pinching it closed, and on release the sleeve reopens by its own tension and medium pressure. To guarantee full closing, a differential pressure of at least 2.5 bar between operating and medium pressure is required.

The VZQA offers nominal sizes DN 6, 15, and 25, with process-valve connections of G female thread, NPT female thread, or clamp ferrule (ASME-BPE, DIN 32676); flow coefficient Kv ranges about 0.7–18 m³/h. Nominal pressure is PN 10 with 16 bar burst pressure; medium temperature reaches -5 to +150 °C depending on element material, with maximum viscosity of 4000 mm²/s. Shut-off elements are NBR, EPDM, or silicone, and housings are high-alloy stainless steel (1.4301/1.4435) or aluminum.

Typical Applications and Selection

The VZQA pinch valve is especially suited to applications demanding media purity, cleanability, or resistance to particle abrasion — food and beverage, pharmaceutical, chemical dosing, and powder/granulate conveying. Selection should weigh medium type, viscosity, presence of particles, temperature, pressure, NC/NO choice, element material, connection form, and any food-grade or end-position-sensing needs.

Doskee Automation specializes in industrial automation and pneumatic components, offering selection and sourcing support for Festo VZQA pinch valves, spare shut-off elements, and accessories. If you’re looking for a dead-space-free, easy-to-clean process valve for viscous, abrasive, or particle-laden media, please contact us for selection guidance and a quote tailored to your medium, temperature, and connection requirements.

Reference: Adapted from Festo VZQA pinch valve product materials