A pinch valve (also known as a hose pinch valve ) is a special valve used in many industries, including process water and wastewater treatment. process water and wastewater treatmenttreatment. It is characterized by its simple design, high reliability and excellent resistance to abrasive and corrosive media. The operating principle is based on the mechanical squeezing of a flexible hose or sleeve, which controls the flow of the medium.

Technical background of the pinch valve

1. structure and components

A typical pinch valve consists of the following main components:

• Housing:

  • Can be made of metal (e.g. stainless steel, aluminum) or plastic (e.g. PVC, PP).
  • Protects the internal cuff and ensures mechanical stability.

• Cuff/tube:

  • Flexible component that comes into direct contact with the medium.
  • Materials: Elastomers such as natural rubber (NR), EPDM, nitrile (NBR) or silicone. These depend on the chemical resistance and temperature requirements of the medium.

• Actuation system:

  • Manual: Via handwheels or levers.
  • Pneumatic: Use of compressed air to actuate the squeeze mechanism.
  • Hydraulic: Use of fluid pressure for control.
  • Electric: Electric motors that move the squeeze mechanism.

2. mode of operation

The pinch valve controls the flow by squeezing the flexible sleeve. It is actuated by:

• Pneumatic pressure:
  • Compressed air is applied to the outer shell of the sleeve, causing it to shut off the flow.
• Mechanical pressure:
  • An external mechanism compresses the cuff to block the flow.
• Springback:
  • When the pressure is released, the cuff opens automatically as it returns elastically to its original shape.

3. types of pinch valves

• Single-seat pinch valves:
  • Cuff is squeezed at one point.
  • Suitable for applications with low flow regulation.
• Two-seat pinch valves:
  • The cuff is crimped at two points to ensure complete closure.
  • Ideal for abrasive or highly viscous media.