More pressure pot questions

[BoomerangInfo]

Hey gang,

I tried my Supercheap pressure pot for the first time today, and it didn't go well. I've made no mods - just tried to use it as purchased, with thread tape on the joins, with just 1 blank sitting inside. Problems were

1. The quick connect from the compressor into the pot leaked. It was audibly gassing out - if I lifted the hose straighter, the leak sound disappeared. The leak was on the QR side, not the screw on side. How the heck do you stop a QR link leaking?

2. The pot safety valve opened at about 45psi. I thought the instructions said it was rated to about 100 psi? (misplaced the instructions atm). I'm pretty sure it made a comment about not going over 50psi inside the pot, although I'm not sure where, as it seemed to be talking about two different pressures in the pot at the same time. How am I supposed to get 60psi in there?

3. Even with the QR hose held straight so I couldn't hear it leaking, the pressure still fell from 45psi to about 20psi in maybe 10 - 20 minutes? I put it up to 45psi again before we went out - 3 hours later there was 0 pressure in the pot, so I have major leakage somewhere, although I couldn't really here an obvious leak. Do I just do the soapy water thing all around & find out where it's getting out?

4. I'd like to not destroy the pot for painting, but would like to get the hoses off. Anyone know if there is some sort of stop fitting that I can place on the pot regulator outlet, and paint outlet just while I'm doing casting, and where to get it? My first stop would be Supercheap again I guess, and secondly a plumbing supply store? Just not sur eif such a thing exists here in the first place.

Thanks. Russell.

[gawdelpus]

Russel I have one of these still unopened in a box. will pull it out tomorrow and see if I can check the threads and bits ,will get back to you.

Ok curiosity got me ,went and opened the box, On the instructions it says max rated pressure is 80 lbs psi. but says not to go over 50 psi, I guess the pressure cutoff is below that .says working with paint usually 25-30 lbs pressure , you may need a non return valve from the compressor to hold pressure once obtained at your max ,also may need a plug for the fluid outlet connection as you won't be needing that until you do some painting. If you can't find the instructions I can scan and send to you ! most times you will need a better thread sealer than tape alone as well.re the quick connects ,no idea how to stop them leaking ,just probably poor quality as usual in these things :( .

[BoomerangInfo]

On the instructions it says max rated pressure is 80 lbs psi. but says not to go over 50 psi, I guess the pressure cutoff is below that .

Yeah that's the problem, although as I said the safety opening is even lower that 50psi, about 45. I'll have to review Fred's thread and see if he removed the safety because of this.


re the quick connects ,no idea how to stop them leaking ,just probably poor quality as usual in these things :( .

Well that'll be a PITA, as they're a permanent part of the only airhose I have, and I imagine the chance of trying to get a replacement that works any better is probably slim, assuming I can even get a replacement as they didn't even have the original on stock. Why the heck they wouldn't supply each compressor witha matching hos ein the first place is beyond me, but that's different story.

Russell.

*EDIT*


If you are worried about not using the safety valve, you can fit that instead, it can still be pulled to release pressure. There have been quite a few reports from people that this safety valve is the main culprit for the pot losing pressure over a period of time, so I eliminated it.

Hmmm, I can see this safety valve is going to cause me grief. WIll have to check all connections for leaks today & see exactly where my problems are.

[gawdelpus]

With the quick connects you could try wrapping some thin paper around the tapered part below the groove ,as that is the joint part ,and may not match correctly, especially as you say it leaks more if you put pressure on one side.tells me it is moving in the taper.If that helps glue some on to make it seal better, In my case if I had that problem here I would machine an "o" ring groove in the tapered section of the coupling and put an "O" ring in to seal it better. Cheers!

[DJ’s Timber]

Unscrew the male connector from the pot, screw a ball valve on and then put the male connector back on. That way once you get it up to pressure , you shut the valve off which will eliminate any leaks from the quick release connector.

I have rarely seen a quick release air fitting that will consistently hold it's pressure over a long period. Of course this will only work after you've traced down and fixed any other leaks on the pot :doh:

[BoomerangInfo]

Unscrew the male connector from the pot, screw a ball valve on and then put the male connector back on. That way once you get it up to pressure , you shut the valve off which will eliminate any leaks from the quick release connector.

Cool thanks. And they're commonly available? I'm afraid I've never done a single plumbing thing in my life, except some PVC rainwater connections.

Russell.

[DJ’s Timber]

And they're commonly available?

Yep, every plumbing store carries them, in fact I'mm 99% certain that Bunnings even stock them. Just buy one to match your thread size, which will probably be 1/4" or 3/8", cannot remember right now with out looking at mine :doh:

[BoomerangInfo]

Well it just gets better. Found several more leaks - the T connector on the pressure gauge leaks in two spots, one being where there is an internal rubber seal, and thread tape isn't helping.

Even worse, the paint gun leaks air at the paint outlet, and no adjustment of the knobs seems to be changing that, and trying to connect the other end of the air gun hose back onto the regulator output, the darn connector nut snapped in two!!

So, looks like it's a visit to the returns department, and hopefully at the same time I can find some valves to seal up some of these leaks. Still no luck adjusting the pressure within the pot any higher, the safety definitely cuts off around 50psi, and I'm not game to remove it completely at this stage. Assuming I get everything working OK, I hope 45psi will be sufficient.

Russell.

[Simomatra]

Safety valves are there for a reason and should not be removed if you value your and anyone else life.

As an ex seafarer who worked in engine rooms I have seen what happens when the safety does not work and it is not pretty.:o:o:o

[BoomerangInfo]

Yeah I'm not keen on running without the safety either, just everyone says 60psi, and I can only get 43psi (the box actually says "operating pressure 15-43psi").

I got a replacement pot today. Found a plumbers, and $32 got me a ball valve and 2 stops so know I'm running with no hoses. It was $29 extra for some thread paste which is a permanent seal, so I skipped that one for now. Managed to get 40psi and lose 2psi/30 mins atm. Hopefully I can find that last leak and get it sorted tomorrow.

Russell.