Monthly Archive for November, 2008

Pneumatic pinch valve, 1/2″ version

After successful testing of my prototype pneumatic pinch valve with a 3/8″ bore, I proceeded to design an improved version with a full 1/2″ bore. This version uses silicone tubing instead of latex, which I believe will not contribute any off-flavours, and will not break down eventually as latex tubing is prone to do. In addition, it also has pipe-thread connections for inlet and outlet so it can be plumbed into a system easily, but can be removed if necessary.

See my page here on how it was constructed.

Pneumatic pinch valve

In a previous post, I wrote about an experiment at building a solenoid pinch-valve, as an inexpensive alternative to the exorbitantly-priced solenoid valves commonly used in automated homebrewing systems. That attempt was a failure, not even able to seal against 5psi pressure.

I have since attempted another approach: a pneumatic pinch valve. The idea here is that the fluid is carried through a length of flexible tubing, and that flexible tubing is run through a rigid jacket that can be pressurized with air (or another gas or fluid). If the control pressure is high enough, it will squeeze the flexible tubing shut, and pinch off the flow of the fluid.

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