How much pressure?

I am taking the Brewhemoth to NHC (as a vendor), how high of a pressure would it take to impress folks? 30 psi, 50 psi? What do you think?

I’m not sure I understand the question . . . you want to pressurize the fermenter and want to know how high you should go to impress people?  30 psi should be enough for most applications.  My fermenters max at ~13 psi, if they would hold 30 psi that would make my life easier.

Any pressure vessel that hold over 14.9 psi have to be certified.
Do not play with fire.

+100.  An employee at Redhook brewery was killed last year by an over pressurized keg.

Thanks, I didn’t know this.  My fermenters have PRVs on them set for ~13 psi, but I know they are rated for 15 psi only so I don’t mess with them.  Exploding fermenters = bad.  Very very bad.

it was a plastic keg, just to be clear. Sanke kegs are designed for 600 psi.

Are you testing with air or water?

Being in construction, I personally know that air tests are death traps. They fail without warning and throw shrapnel everywhere.

If I knew you were doing a pressure test “to impress people” I would stay out of the room. Sadly, most people wouldn’t know what was going on and be blissfully unaware that they were in serious danger.

Do not do this.

My first thought too. The owner of West Country Cider in Mass was killed a few years ago by an pressurized vessel that failed.

It is always good practice to take the safe route with pressure vessels.

What is the factor of safety on the design? Are there fail safes?  Sanke kegs are designed for 600 psi, Cornies say 130 psi, and we serve at say 10 psi which gives a safety factor of 60 and 13. Cornies and Sankes have PRVs also. We all know the amount of kegs that will be around, but we are familiar with those, so we don’t even think of risks. I don’t think much about thrones in the basement, or even the water heater in the basement (see Mythbusters).

Not trying to say it is all ok, I know of cases where fermenters have blown. What is the safety factor, back ups and certification? That is what I would ask.

Being somewhat of a noob when it comes to commercial brewing and pressurized vessels I can tell you that I certainly wouldn’t be impressed by a potential catastrophe:D

To my knowledge Sankey kegs do not not have PRV.
It is the keg dispensing coupler that has it.
The keg couplers used for filling and cleaning do not have PRV.

14.9 Psi in pressure vessel is still a lot of pressure.
I tell you this from my own experience.
I was cleaning 15 BBL bright tank.
I was depressurizing it from bottom port.
When tank had about 1-2 psi pressure (by pressure gauge) I decided to open a 4" top port.
Lucky me that my head was not over the port because 4" end cap shot up like a bullet.
It is not a lot of fun when there is 4" piece of metal flying around you.

Needless to say I make sure that there is no pressure before I open any pressure vessel now.

That is true that Sanke couplers have a PRV, but we pressurise through the coupler. The guy who died with the plastic keg was using it on a sanke stand, which was set at a pressure that a sanke could take.

A little pressure over a large area equals a big force.

If the fermenter is not specifically designed to hold pressure, your high-pressure demo would leave the opposite impression on me then you intended.  In fact, it would scare the hell out of me because my assumption would be that it would not be designed for holding a significant amount of pressure.  I have spent many, many years in laboratories with both large surface area pressure vessels and vacuum vessels.

On the other hand, if they are rated to hold, say, 100 psi, and you are demoing them at 80 psi, my question would then be: why I would ever want my fermenter to be at 80 psi?  I would be much more impressed with clear demonstrations of the features I would care about:  easy access, easy to clean, easy temperature control, etc.