Restaurant Kettle Explodes

[fixbear]

Technically a steam kettle is a boiler.  In my state boilers have to be inspected twice a year and pressure tested once per year.  Not certain if there is a exemption for steam kettles from that ruling. But steam is the most powerful of forces.  We have no way of containing it even today.  Look at a volcano.  It’s when water goes down through the aquifer and hits the high temp lava that  makes the megaton explosions like mount St Helens.  If you are going to work on steam,  Get all the training and knowledge you can before turning the first wench or valve.

[john]

I’ve referenced the linked video previously both here on the forums and in blog posts about safety. It’s surprising to me that people would neglect, or worse, circumvent safety mechanisms to force a machine to run. It’s not hard to test the pressure release valve on a boiler, and the steam keeps it from getting gummed up. I mean, if nothing else, you’re standing next to a literal bomb if that pressure can’t escape safely. Something about that would make me a bit more cautious. 

 

ectofix, I seem to recall you sharing a photo of some kind of gauge set up on a steam kettle(?) that you LOTO’d and removed.

 

One thing I admittedly am glad to never have faced is an angry customer at a business who just wants you to “make it work, now” without regard for the proper way something should be fixed. How often do you, as techs, get a call like that, and how do you handle it?

[olivero]

Where I work its always a matter of getting it fixed ASAP but I don’t care what the customer says or wants in that regard, i will never fix a unit and make it unsafe to make the repair “faster” or so they can use it. NEVER would I do that, I have gone routes to see if I could bypass one of the 2 burners in an oven so it could run with just 1, but that was something I worked with the manufacturer one.

 

If there is a tech willing to make equipment unsafe or rig it together to make it run but it might break down worse or injure someone, they don’t deserve to be a tech.

[fixbear]

I actually used to test and certify boilers. Safety valves are removed and tested on a hand pump with a certified gauge.  The pressure vessel has safeties removed, all air vented, (air is a energy storage), and the vessel is hand pumped up to 150% of max rating pressure.  Sometimes they don’t make it,  but with solid liquid in it, it isn’t mush of a boom.  Yes I got wet a few times.

 

   As for control  safeties and mechanical safeties, Not a wise decision to bypass or defeat.  But it is advisable to help the customer find a solution after you have to red tag his machine.  Yes, I know some are impossible to satisfy.  But smiles, explanations, and a positive feeling helps them to get through the situation. 

[ectofix]

partstownjohn, this is probably what you’re referring to.  Yes, I discovered this shortly after I started working where I do now:

 

 

 

This is a kettle supplied by live steam.  The building’s boiler is set for 90 psi.  This particular kettle is rated for 50 psi, so a PRV steps its pressure down.  Luckily, the only over-pressurization to occur was me blowing my top when I saw this.

 

The other kettles on this cook line are all rated up to 100 psi.  I don’t know why this one had to be the oddball.

[olivero]

Wow… I would have been reeeeeaaaalllyyyy p-i-s-s-e-d if I saw that.

[john]

So, you still had to step the pressure down using the PRV, but had to move the safety valve to the kettle side?

[ectofix]

Just like your home’s water heater having a T&P relief valve mounted directly to the water tank, the safety relief valve on a steam kettle should be mounted directly to the kettle’s jacket…just like it was when it left the factory.

 

In my picture, all that extra plumbing…and ESPECIALLY that globe valve…shouldn’t have been there.

 

The PRV I mentioned just reduces steam supply pressure to what I set it.  I have it set to around 35 psi, which provides a surface temperature inside the kettle at around 275-280°F.