Possible DIY spunding valve

So I'm looking to get/make a spunding valve before I do my next lager and I found this valve online.

http://www.tractorsupply.com/air-co...-1-4-quot-mnpt-inlet-x-14-fnps-outlet-3300116

Looks like it could be used as a spunding valve out of the box, with the appropriate connectors. My only worry was that it since it appears to be designed for high flow rates, that it might have trouble holding the pressure at the very low flow rates through a spunding valve. Thoughts? Has anyone used anything similar?

jar1087 said:

I found this valve online.

Click to expand...

That's exactly what it is. It's just a valve with a gauge on it, not a real pressure regulator.

It won't work.

That looks pretty cool.
Since the gauge is 0 to 125 PSI @ 5 psi increments, I wonder if that is a tight enough range to dial in for kegging?
The DIY ones I have read about say you want a 0 to 30 PSI range??
I assume it would work you just wouldn't have as much control?

dzlater said:

That looks pretty cool.
Since the gauge is 0 to 125 PSI @ 5 psi increments, I wonder if that is a tight enough range to dial in for kegging?
The DIY ones I have read about say you want a 0 to 30 PSI range??
I assume it would work you just wouldn't have as much control?

Click to expand...

Unfortunately, flow rate meters won't work right for kegging (Spunding value is a different beast). They simply limit the gap so that a gas can only flow so fast from the IN side to the OUT side. Given enough time the IN side and OUT side will equalize in pressure.

Imagine if you had a pinhole leak between a filled ballon and an empty one. The flow between them is going to be very slow, but eventually the pressure will equalize. These kinds of things work on air tools because the pressure gets turned into a mechanical force and the gas is vented so there isn't a way for the pressure to build up while the tool is in use.