Pinch Valve Operation
Operation Pressures
Operating pressures for controlled material vary
depending on sleeve elastomer and valve size, and can range from a moderate
vacuum (up to 26" Hg) to a maximum of 90 psi when controlling with air.
Required control pressure is normally 20 to 40
psi greater than the material pressure. Use of excessive actuation
pressure (air or liquid) than that which results in complete valve closure will
impact sleeve life. Use of actuation pressure above 90 psi is not recommended.
Recommended Configuration

Airpinch pinch valves are normally open and require
constant pressure for complete closure. Therefore, a loss of control pressure
will allow the valve to open. In the event of sleeve failure, controlled
material can enter the actuation system.
CAUTION: Airpinch pinch valves should not be
used in applications where such conditions could cause system damage or failure.
The designer must recognize that sleeve failure can occur at any time.
The actuation valve controlling the Airpinch must
have free exhaust to allow the Airpinch to open. A solenoid, manual, or
air-pilot operated 3-way control valve is required. A check valve cannot be used
between the Airpinch and exhaust port of the controlling valve. Using a QEV can
improve valve opening response time.