Help me figure out what's going with my 7 gal unitank! (losing pressure, possibly)

[welly3]

Hey all,

I don't know when this started happening but basically it seems my SS Brewtech unitank has started losing pressure.

I have a CO2 line hooked up to the blow off tube which was set to 15PSI on the gas regulator and was showing just slightly less than that on the unitank pressure gauge. After a few hours I saw the PSI on the unitank pressure gauge drop, which makes sense as the water - currently I'm just testing with water before I stick a new beer in it - was absorbing the CO2 so upped the CO2 pressure on the regulator to bring it back up to 15PSI in the tank.

Few days later, I've checked it and it's down to 0 on the unitank pressure gauge. If I increase the PSI on the regulator, because it's now up to over 15PSI, the PRV on the top of the unitank vents and releases gas.

I've tried hooking up the gas to the carb stone port and the blow off tube - CO2 doesn't increase. I'm assuming the water has taken on as much CO2 as it can but surely it would still show the tank being under pressure? And I'm pretty sure that if I loosened up the PRV on the top of the unitank it'd literally hit the roof, given it vents so when I up the pressure. So something is amiss - I'm not sure if I've got a leak in the tank or if the pressure gauge is knackered or if the PRV is knackered - although I've got two PRVs and have swapped both of them around.

Also, I've done a starsan spray test on all the fittings and nothing immediately showed like it was leaking. Triclamp gaskets are all pretty new as well.

Am a little bit at a loss here! Advice/ideas would be appreciated! Maybe I should stick the unitank in the bath and check for leaks?

Cheers!

 

[Buffers brewery]

IMO leak testing anything using CO2 and water is a no no. Air over water or gas (CO2) only is OK. I made a little gadget with a Schrader type valve at one end and a quick release at the other so I could use a car tyre pump to pressurise my kegs with air.

 

[welly3]

IMO leak testing anything using CO2 and water is a no no. Air over water or gas (CO2) only is OK. I made a little gadget with a Schrader type valve at one end and a quick release at the other so I could use a car tyre pump to pressurise my kegs with air.

Yeah, I might try dumping the water and filling up with just gas and see if it retains pressure. Cheers!

 

[MashBag]

Have you tried a mild solution of washing up liquid an a spritz bottle. Spray all fittings?

 

[welly3]

Have you tried a mild solution of washing up liquid an a spritz bottle. Spray all fittings?

Yeah, well tried with a foamy starsan solution and nothing seemed to bubble or fizz. I'm going to dump the water, fill it with co2 and try that next. Then if no joy, I'll stick it in the bath.

 

[MashBag]

Rather than leaking, could it be adsorbing?

 

[welly3]

Rather than leaking, could it be adsorbing?

There was certainly a bit of that but after doing some further investigation, it seems the pressure gauge on the unitank is knackered.

Was on the phone with someone at the malt miller to try and figure out what might be at fault and we seem to have come to the conclusion that it was the pressure gauge.

Even though there was plenty of pressure in the tank, the pressure gauge was showing there was nothing. I know this because removing one of the blanking plates while the pressure gauge was showing 0 psi fired it off like a bullet! Won't be doing that again and of course I should have realised something like that might happen.

I've got a replacement ordered and hopefully that'll fix it!

 

[MashBag]

Good find. Lets hope the new one fixes it.