My Rix SA-6 Diesel

[-JD-]

[snip]
You can use a PMV as a check valve but its not really ideal.

What are the negatives?
How "bad"?

 

[rhwestfall]

You searched for check valve - Page 2 of 2 - August Industries Inc.

 

[rhwestfall]

Back Pressure Valves - August Industries Inc.

 

[rob.mwpropane]

You searched for check valve - Page 2 of 2 - August Industries Inc.

If you're referring to me then yes I did and that's what I assumed that it was, but I was told it was a PMV;

Its a PMV, and yes it doubles as a check valve
back-pressure-regulator-1-to-10-cfm

A PMV is just a check valve with a 2000psi spring holding the ball back from opening until there's lots of pressure. A check valve by itself would open at ~1psi

@rob.mwpropane you can just leave it there to act as a check valve or move it downstream of your tower. You need to add whatever you are missing (check valve or PMV)

 

[rob.mwpropane]

Is there an easy test if / when I get this PMV or check valve in my hand to confirm what it is? I'd like to change things up at the compressor and have the OPV upstream of this piece for safety.

Can I manually blow through a check valve but not a PMV? I believe a check valve only needs ~ 1psi or so to open?

 

[Couv]

It depends on the check valve. Most of the time 1 or 2 psi (or less) is all it takes to open a check valve in the desired direction. Of course it should hold all pressure in the opposite direction. A PMV should not open until the desired pressure is achieved-usually about 2000 psi give or take a bit. So yes, easy enough to test. Remember, you want the gauge on upstream side of the PMV to find it's cracking pressure.

 

[rob.mwpropane]

It depends on the check valve. Most of the time 1 or 2 psi (or less) is all it takes to open a check valve in the desired direction. Of course it should hold all pressure in the opposite direction. A PMV should not open until the desired pressure is achieved-usually about 2000 psi give or take a bit. So yes, easy enough to test. Remember, you want the gauge on upstream side of the PMV to find it's cracking pressure.

Understood, that's what I was thinking.

As far as the gauge goes, I believe having it connected right at the 3rd stage coalescer would do just that. Wherever it holds before it starts flowing into the tower would be where it's set? It wouldn't start climbing until the tower was pressurized beyond that.

 

[Couv]

I'm not sure I'm following you. To test a one way valve: Supply pressure-->one way valve-->put your finger a balloon here and you should get flow. Reverse the valve and you should not get flow.

To test the PMV: Supply pressure-->gauge--->PMV -->put your finger a balloon here . You should not have any flow until the PMV opens at the predetermined pressure (around 2000 psi.)

 

[rob.mwpropane]

I'm not sure I'm following you. To test a one way valve: Supply pressure-->one way valve-->put your finger a balloon here and you should get flow. Reverse the valve and you should not get flow.

To test the PMV: Supply pressure-->gauge--->PMV -->put your finger a balloon here . You should not have any flow until the PMV opens at the predetermined pressure (around 2000 psi.)

Yes Sir, understood about testing with it off in my hand.

I meant testing to see where it's set with the unit running and watching the gauge (if it is a PMV).

 

[Couv]

Yes, at what pressure will the balloon start to inflate? That is what you want to know.