Issues venting pressure pot

[RGABEL]

I just modified the Harbor Freight paint tank to a resin pressure pot. In testing I am having an issue evacuating the pressure. I open the ball valve, but no air escapes, I need to pull on the pressure relief valve to get it to depressurize. Obviously not ideal. It almost appears I am pulling a vacuum that is preventing either the valve or the regulator to release the pressure. Any thoughts? Below is how my piping is set-up (not my set-up but all the same components).

UPDATE: Now it will not pressurize either. Something with the regulator?

 

[Monty]

My WAG is that it is the regulator. Don't know why you would need a regulator. Where you have the regulator, I just have a tee.

 

[Kenny Durrant]

I don't have regulators on my tanks. I have pressure gauges, pop off valves and a ball valve. I have a regulator on the end of my hose with a disconnect. The regulator regulates the pressure going in and I leave the air connected the whole time because of leaks too small to fuss with. I connect the hose to a ball valve that's attached to the tank so I can fill the tank with air slowly. Then when time to demoed I close the valve and disconnect the hose. Then I'll open the ball valve on the tank to bleed off the air then done.

 

[MRDucks2]

My guess would be that you have your regulator plumbed incorrectly. All of the ports may not be created equal.

 

[RGABEL]

Thanks for the suggestions. I did verify the plumbing on the regulator is correct. I have a regulator in the pot as my compressor is set to about 120 PSI for the shop. I do have another high quality regulator that I could use for the same purpose, just does not pipe in like the one that comes with the tank does.

 

[Kenny Durrant]

I'm assuming the statement "The Regulator isn't plumbed correctly" is that it's in the wrong place. You shouldn't bleed off pressure through the regulator. I apologize if that's not a correct interpretation but it might be worth looking into.

 

[RGABEL]

Well I got it to work. Kenny, I am bleeding through the regulator as that is what seems to be the practice from all of the you tubers posting how to do this. I learned that at the higher pressure I need to just crack open the valve to vent, once it gets to 20 PSI or so I can open to let it out quicker. I think this is fine as there is no need to depressurize quickly.

Thanks all.

 

[Curly]

Regulators are not designed to flow backwards so don't depressurize that way. You could damage it and have line pressure flowing into the pot. Boom!!!

If the capped side of the regulator has an arrow on it pointing away from the body then put a ball valve on it and drill the cap with a 1/16 bit or get a plug and do the same. You want to have regulator, ball valve and drilled cap/plug. The drilled cap will let the air bleed off slowly and safely when the ball valve is opened, depressurizing the pot.

If the capped side does not let air flow out that way pull the overpressure valve out and replace it with a T fitting. Put the overpressure valve back on one side of the T and the ball valve and drilled plug on the other. Then you can safely drain the pot.

 

[MRDucks2]

Well I got it to work. Kenny, I am bleeding through the regulator as that is what seems to be the practice from all of the you tubers posting how to do this. I learned that at the higher pressure I need to just crack open the valve to vent, once it gets to 20 PSI or so I can open to let it out quicker. I think this is fine as there is no need to depressurize quickly.

Thanks all.

Bleeding through the regulator directly, unless it has a port specifically design to do so, will ultimately damage it.