Page 1 of 1

Would this keg be safe as a Boiler?

Posted: Tue Oct 02, 2012 2:52 pm
by Soggy Bottom Boy
I have a keg similar to the keg as pictured below, only mine has the standard U.S. tap configuration instead or the one shown in this pic:

Image

My concern arises from the fact that the side bung hole seems to be surrounded by a welded up, enclosed air space. I assume that is there to reinforce the side of the keg for when a bung is pounded in.

Is there a danger of this section rupturing if used as a propane and/or electric boiler? Sorry if this has already been covered before, but my searching attempts came up empty on this matter.

If it is deemed unsafe as a boiler, my other ideas for using this keg would be to cut out the bottom and convert it into a conical fermenter by welding some legs on the sides and a cone with appropriate fittings to the bottom..... or, perhaps use it as an outer shell for a proplyene glycol filled double boiler with a slim quarter barrel keg holding pulpy fruit washes.

I have not built a single thing as of yet, just doing a lot of reading and trying to get things straight in my mind. Most definitely will start with a simple keg based pot still to start with.

Crawl, walk, then run! That is the plan here. =O)

.

Re: Would this keg be safe as a Boiler?

Posted: Tue Oct 02, 2012 3:23 pm
by maheel
they work fine there is only slightly more than "zero" working pressure in a still boiler

some of them are 80L size...

some weld a plate over that side bung hole if you dont have a proper screw in bung

a beer home brewer would quickly swap you for a 50L as they make great wort boilers if it's a 80L :)

Re: Would this keg be safe as a Boiler?

Posted: Tue Oct 02, 2012 4:18 pm
by Soggy Bottom Boy
I don't think that you understand what I mean by "a welded up, enclosed air space" on the side of the keg. I realize that there is very little pressure on the inside of a boiler if the product condenser tube is not clogged or closed off somehow.

If you look closely at one of these kegs, where the bung hole is, the side of the keg wall has been dented in about 3/4", and a (sort of)rectangular plate is welded to the outer side of the keg to match the curvature of the rest of the keg, with the tube of the bung hole walls welded between them. Essentially there is a completely enclosed pocket of air about 8"X8"X3/4" welded to the side of the keg.

I have seen pictures of an exploded rolled chime (complete with shrapnel) on the bottom chime of a modern straight sided keg due to a combination of plugged (or no) vent holes in the chime, and propane burner.

I suppose that the simple solution would be to drill a hole in the outer patch, close to the bung hole. I wouldn't think that there would be any vent holes on the inner wall of this pocket, as it would be impossible to sanitize at the brewery.

Any other thought or opinions?


On edit: Oh, the one that I have is a 15.5 gallon

Re: Would this keg be safe as a Boiler?

Posted: Tue Oct 02, 2012 4:40 pm
by Dnderhead
"Essentially there is a completely enclosed pocket of air about 8"X8"X3/4" welded to the side of the keg."
no ,its filed with ??????

Re: Would this keg be safe as a Boiler?

Posted: Tue Oct 02, 2012 5:55 pm
by Soggy Bottom Boy
Dnderhead wrote: no ,its filed with ??????
Well, I suppose it would actually be argon gas for the sanitary welding process, not air. For sure it is not liquid filled by anything that would fill the keg, such as beer. ...and definitely not 3/4" thick of stainless steel.

I will try to get a good picture of the inside, but without a bore scope and camera attachment, I think it won't turn out very good.

Re: Would this keg be safe as a Boiler?

Posted: Tue Oct 02, 2012 6:50 pm
by Dnderhead
dont know but,,,
one i took apart had a aluminum insert,then filed around that,with ? plastic?,, epoxy?,,,plaster?

Re: Would this keg be safe as a Boiler?

Posted: Tue Oct 02, 2012 8:20 pm
by Soggy Bottom Boy
Here are some pics:

First the inside, looking down through the spear hole:

Image

You can see where the side of the keg was pressed inward with strengthening ribs embossed as well. The dark circle with the bright spot is the bung hole.



Next is a pic of the outside of the keg:

Image

You can see the outer ss plate welded to the keg and the bung hole tube. It is for sure hollow, with no sort of vent hole anywhere. I suppose that the void could be under a vacuum because the gas would have been pretty hot at the time the weld was completed, I'm not a welder, so not exactly sure how that would play out. I guess if nobody has heard of one going BOOM, maybe it's a non issue.


.

Re: Would this keg be safe as a Boiler?

Posted: Tue Oct 02, 2012 8:49 pm
by rubber duck
So poke a hole in it, that way you never have to worry about the gas expanding.

And yes it could be a problem if you don't vent it. Look up exploding keg rim.

Re: Would this keg be safe as a Boiler?

Posted: Tue Oct 02, 2012 9:39 pm
by Soggy Bottom Boy
rubber duck wrote:So poke a hole in it, that way you never have to worry about the gas expanding.

And yes it could be a problem if you don't vent it. Look up exploding keg rim.
Soggy Bottom Boy wrote:,,,,,,I have seen pictures of an exploded rolled chime (complete with shrapnel) on the bottom chime of a modern straight sided keg due to a combination of plugged (or no) vent holes in the chime, and propane burner. ......
Yes, I have seen that one. Most definitely will poke a couple of holes in the outside wall if I ever put heat to it, now that I have had a better look at the inside!

The more I think about it, the more I like the idea of making a conical ferment vessel out of this one. The base is narrower than a straight side keg too, so perhaps not quite as stable sitting on a burner with a tall column and condenser on it.

.