Tubes...leaking

[NP317]

[snip]
The steam dome only has a few 1/4" holes into the boiler.
Tom

Time for that endoscope.
I purchased an inexpensive one on Amazon that works with my smart phone via wi-fi interface.
Find the smallest diameter camera end available: usually 5mm or less. Very useful.
RussN

[Bill Shields]

Perhaps you could 'scope' down one of the boiler fittings - say the safety valve..which may well have a larger diameter hole.

if / when you decide to retube the boiler, suggest you get that 'opening' made = ID of the steam dome ring so that you can get in and 'look about' occasionally.

Southern CA has a large number of steamers and clubs, and (used to have) multiple representatives of the boiler building / repair trade. Since I make my own, i have not really looked specifically in that area this millennium (or earlier).

However, once you get the boiler off and on a pallet...you may well find that the most competitive / competent repair / replacement agency is 1/2 a country away (say middle America)...at which point it is just shipping charges...

[Emfinger]

You can blow up the picture and see that the tubes look welded, but not to the sheet. So are the rolled of welded???
Thank you
Tom

[milwiron]

Welded but some of the beads don't penetrate the sheet. That's the way it appears to me.
Denny

[Emfinger]

None of them have penetrated the sheet...not welded to the sheet......what the sheet? The leak is on the inside, just behind the "weld" or rolled lip ? I'll retest with pressure but the rust in the other tubes is from me blowing out the firebox and blowing water into several tubes.
I refilled the boiler and the water poured out...from that one tube. By morning the water was all gone (down to the tube)

Anyone know of a 40 year old procedure that involves welding the lip of the tube..but not to the sheet?

Thanks
Tom

[Bill Shields]

So...what would one weld the tube TO? Itself?

Tubes might be proceened (spelling)...but then I have only seen that done on a model boiler once or twice in 50 years. It is a process where the end of the tibe is rolled over after the tube is rolled into the sheet.

However based on what I see here and in the previous picture. I would just offer that it is just a crappy no penetration weld job

Water pouring out is a confirmation that tubes need to be replaced

[FKreider]

What I think we might be seeing here is the tubes were originally welded to the tubesheet however as suggested above the weld did not properly penetrate. Over the years as the boiler was heated and cooled and the metal contracted and expanded the tubes/welds have basically pulled away from the tubesheet allowing the leaks that you are seeing now.

[Bill Shields]

Agreed...

A polite and astute way of describing a crappy weld job

Stay bolt welds do not look terribly spiffy either...looks like something I would do

[LVRR2095]

So...what would one weld the tube TO? Itself?

Tubes might be proceened (spelling)..

Bill, I think you may be referring to the Prosser method of tube installation where the tube is expanded behind the tube sheet, then rolled and beaded.

Keith

[Bill Shields]

That is it...thanks..but I doubt it is the case here

[Marty_Knox]

Proper installation of steel tubes consists of rolling the tubes in the sheet with about 1/8" projecting,
seal welding the tubes to the sheet, and then re-rolling.

[rkcarguy]

From what I can see in the pictures, the welds look like they lack penetration somewhat, but I would guess that the tube has cracked or corroded right behind the weld in the "heat affected zone". Unfortunately, time to tear it down and re-tube the boiler. If it's 40 years old, it's probably time.