How flameproof is a kettle ball valve?

[flocculated]

So I'm thinking of doing an incremental upgrade to my current stovetop biab setup and adding a ball valve to my 19L Big W pot for recirculating during mash and also for draining.

My question is, if I add a ball valve from ebay or LHBS could this get damaged from the heat during the boil?

I'm just using the large burner on my gas stovetop, but there is a little heat "spill" up the sides of the pot, especially if it's a little off-centre.

Given the size of some people's outdoor burners, I thought it must be okay, but didn't want to wreck a pot and a valve without checking...

 

[Mardoo]

I haven't had any issues, and have disassembled the valve a few times with no noticeable damage to the silicone inside. I use a Rambo burner which generates solid heat whether I want it or not so I'd imagine you'd be fine.

 

[flocculated]

Cheers Mardoo, good to know!

 

[MaltyHops]

Ummm..... kettle tap went BOOM!

 

[Mardoo]

Well there ya' go! However, I've specifically avoided having "flames ... licking up the front of the pot quite a bit and onto the valve tap". That seems pretty careless. They aren't made of adamantium...

 

[Adr_0]

Hmmm. At minimum the handle sleeve will melt, but worse than this the seats would probably melt. These are the cup-shaped seals around the ball.

I'm guessing that'd the valve would go boom because of trapped liquid in the ball boiling and over pressuring the ball (as MaltyHops suggested) ...not good!

All of these issues should be able to be solved by bolting some checker plate aluminium somewhere to shields the valve.

 

[klangers]

I second Adr's response.

Some ball valves are designed for high temperature steam applications (with metal or Viton seals), but I highly doubt the cheap ball valves we get on our kettles are anywhere near these.

 

[Mardoo]

I will stand corrected then. Put a flame guard on for safety. Doesn't have to be diamond plate though. But it should probably be adamantium.

 

[Bomber Watson]

Seals in most the half decent ball valves are teflon.

According to wiki it melts at 327 deg c.

I recon flames licking it would be an issue.

 

[flocculated]

I like the idea of a heat shield. Although in my case, it's not like the flames are "licking" the sides, you can just feel the heat coming up the side.

I use a yoga mat insulator during the mash. On my electric hotplate there was minimal heat spill and I could add heat if needed without worrying about melting the plastic. I wouldn't try it on the gas stovetop though.

I'm guessing that many (most?) brewers are using gas burners on valved kettles, and it doesn't seem to be a rampant issue (just the odd kettle tap BOOM).

 

[manticle]

Only negative experience I've ever had was melted plastic handle from 4-ring. I use an ots element these days anyway.
Anecdotal, individual, experiential and all that. Your mileage may vary, blah, disclaimer, woops uncle Bertie.

 

[Feldon]

You could buy one of these heat shields. Only $10 plus shipping from the US (maybe available here in Aus - I haven't looked).

But it would be easy enough to make for yourself out of a piece of aluminium flashing, the clip, and a few pop rivets to hold it together.

Note that its wider on one side to protect the valve handle when in the closed position from heat rising up the sides of the pot..



https://www.brewhardware.com/product_p/hs.lg.bv.htm

Here's a pic of a similar heat shield made to protect a dial thermometer. It gives a better view of the type of clip that is used. These clips are very common and you may have one lying around. They come in a range of sizes and are available at hardware stores.



Good luck with it.

 

[zeggie]

You can make a cheap $1 heat shield out of an empty tin of diced tomatoes from Woolies

 

[Mardoo]

Do the chickpea cans work, or does it have to be tomato? :huh:

 

[zeggie]

Red cans go faster!

 

[flocculated]

Would it be inappropriate to use a kit&kilo can?

 

[Mardoo]

Oh, you ironic hipsters.