View Full Version : Something to learn from...

12-08-2017, 09:36 AM
I know everyone is super cautious with their cleaning regiment on fermenters in order to prevent imploded tanks, but here is a word of caution that you donít need chemicals to get the same reaction.
We were doing some cleaning end of day yesterday, I boiled some water in the hlt to pump through heat exchanger. End of the day there was 40-50 gal left in our 3bbl hlt. Turn off the heat, to home for the night.
Next morning come into the brewery to an imploded hlt. I had clamped the lid on to keep humidity down in the building, and the cooling air/water in the hlt caused the tank to implode.
Would have never, ever thought this was possible, yet here we are. Hope everyone elseís Friday works out a little better. https://uploads.tapatalk-cdn.com/20171208/f4088d4e481bd5f09e3a5f30de3a4022.jpg

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12-08-2017, 09:47 AM
Pressure/temperature variances are very important to keep in mind when dealing with any vessel heating up/cooling down. Before buying a bulldog, we used to evacuate barrels by filling up kegs with boiling water, letting the keg heat up, then pushing out with CO2 and putting into the walk-in to cool. The vaccuum on the keg was enough to fill it. Hope the replacement doesn't set you back too much :/

12-08-2017, 11:05 AM
No vessel in the brewery should ever be completely sealed. Ferms and brights should always be equipped with Pressure/Vacuum Relief Valves to prevent implosion/explosion from any number of causes. A pumped HLT should simply be vented, with a vent large enough to insure an even pressure balance. If humidity is a problem, use a copper pipe for the vent, run it to the outside of the building, and slope the pipe at 1/4"/foot of run towards the HLT. Most humidity will condense in the pipe and run back into the HLT. Of course, the outside end needs to be protected from insects and birds attempting to make their homes in it.

I know you've learned your lesson, so this for other newcomers to the art.

12-08-2017, 08:05 PM
It looks like you have a vent towards the top of the tank on the left side of the picture, no? I am surprised it wasn't enough to overcome the pressure differential. It could have been aided by the fact the HLT was not insulated, and it's probably pretty cold up in Alberta right now. Quicker temp drop causing a higher pressure differential. The thin wall of the tank couldn't overcome the differential. Tanks have a much higher integrity for pressure than vacuum. Smaller vessels can take more differential than larger ones. Usually they are rated around 0.5psi vacuum unless specifically designed otherwise.

This is what is dangerous about kegs. In years of working with all types of pressure vessels they are the worst design from a safety standpoint. Most have not really had any pressure safety until recently. It has been an option on the tap, but now they have laser etched burst discs in the Frankes at least. Vacuum can be applied to some degree, since the wall is thick, the vessel is smaller, and they kind of have their own vacuum relief. The "ball" of the valve will pull down with enough vacuum allowing air to enter the keg. As long as the differential is not too great, they won't implode.

We used to use 55 gallon drums over a fire and spray them with a fire hose to cause this reaction when teaching haz-mat and fire safety at industrial plants. Makes a great show. Helps you to understand pressure/temp relationship. Also remember this if you upgrade to steam in the future, you'll want vacuum relief valves on those jackets too.

dick murton
12-09-2017, 05:24 AM
I know it has been said before, but it is worth repeating.

When emptying a tank under some sort of top pressure, but using a pump as the main motive force, it is still essential to have anti vac facilities fitted to sealed tanks to ensure that in the event of a gas supply failure or some sort, you don't get the same sort of result. And test and maintain the antivac valves on a regular basis - we had an anti vac system fail due to the rubber perishing and sticking (due to regular steam sterilisation of the tank)

01-08-2018, 04:46 PM
that is spectacular. wow.

thanks for sharing and illustrating an excellent lesson. if just one tank is saved by this thread, well worth it.

01-11-2018, 06:16 PM
Accidents don't just "happen". You might want to chain your CO2 tanks too. Perhaps a safety inspection would be worth the time. How much is it worth for not losing another piece of investment?