Super Heater Return Bends

[4fbuilder]

Good evening Julian,

Re:- Return bends of radiant type must be of stainless and welded up and not threaded and sealed with boss white! Who says?.

I've been putting steam pipework together and trying to take it apart again for the last fifty plus years and I must have been playing with miniature stainless superheaters with screwed return ends for at least the last twenty five and as I said in my previous post, I've yet to have a failure.

Regards,

Bob

[builder01]

Hi Julian and Bob,

I guess my problem is, that I find it frustrating not to be able to make all the parts I need myself. I think everyone can understand that. I have several weeks to decide exactly what I will do.

I am pretty sure that Boss White is for house plumbing. McMaster-Carr has a thread joint compound that is good for up to 2100 degrees F.

Hopefully, and I don't know why I did not think of this before, someone at my club can do the welding for me.

You have all supplied good suggestions and information for me.

Thanks so much,
David

[Roger]

Just one thought on this. I've already seen a post saying that they've had no problem with high temperature Silver Soldering with radiant Superheaters. Personally I wouldn't want to rely on that to secure the end alone because it just might melt. However, if it turns out that they are unlikely to melt, then you could make them as described and then secure them with high temperature Silver Solder. If it ever did leak, it wouldn't be the end of the world, but in normal running it would give a strong joint an seal.

I can't say that I like the design, it's not very elegant and it could pose problems with it getting stuck in the flue if the end is too close a fit. However, making Superheaters that don't require TIG welding is definitely a bonus.

[steamcoal]

These are the photos of kiwinoels Achillies superheater element construction.
The tips were welded while Argon filled





All jigged up and ready to solver solder.

[builder01]

Looks pretty good! I hope mine turns out as well!

David

[92220]

Oct 11, 2016 11:27:17 GMT Roger said:

I imagine the 'double bend' superheaters are thick walled tube, else I imagine they would collapse on bending. Maybe they use Wood's Metal to prevent that from happening though. I'd be interested to see how that's done.

Hi Roger.

As John says, the Hewson superheaters are 5/32 x 24swg tube. I don't know how they bend the tubing but it is a smooth bend - no flattening, so probably they use Wood's Metal as you suggest. They bend them up to your specified length. They charge £33.44 per element.

Bob