Regarding "cascading", has anyone used tubes from another preservation org that could utilize shorter tubes?

To put things in perspective, how much does a typical tube or typical flue (pick a hypothetical length) cost times a typical count of each, presuming ordering just enough for the work at hand with whatever number (if any) spares for work errors but not enough for a future job.

Can you post a link to the source of that HAER document?

Link for EBT HAER info
https://www.loc.gov/resource/hhh.pa3372.sheet/?sp=3

In November, 2016 I got the following price for 2" dia. tubes from my local steel supplier: $37.50 EA PC BASED ON 84 PCS @ 112"

At one time I was going to get a set of used 2" tubes from JDC at the Valley Railroad for the J&L 58. They could be cut down to the shorter length that I needed and they were still in good shape. However, being a state inspected boiler I needed material certs that the Valley did not have, making the tubes unusable to me.

Yes, the pedigree for tubes to be reused is of great importance.

Why do I sense a basis of belief that all tubes need to be swaged before installation in this thread? The "normal" 2' diameter saturated steam lokies I've worked on require no swaging…..…. superheater flues, certainly, but not common firetubes. And, given the higher cost, superheater flues are more likely to be safe ended and reused than small firetubes in my experience as well.

Dave, Do I understand correctly: you don't expand tubes so that after removing the ring weld and rolled bead, a tube can be pulled through the front sheet preserving the end allowing it to be re-inserted, expanded and ring welded again without swaging a safe end on? Is that it or is your point that it isn't cost effective to safe end 2" tubes but it is for flues. That's the question: is it cost effective for (short on resources) museums to find or set up a forge operation for salvaging perfectly serviceable tubes by swaging on replacement ends? Apparently it was even for small E. Broad Top RR. Understood, replacing leaking tubes was probably a daily occurrence, routine work, every wash.

I think there's some confusion on the term "swaging".

I think Dave's referring to the swaging done on superheater flues. For instance, 5-3/8" superheater flues are swaged down to a diameter of 4" (?- something like that) at the firebox end. The end of the flue is heated and forced into a die which "swages" the diameter smaller. This reduced diameter at the firebox end helps equalize the gas flow through the superheater flues in the event of a partial blockage of one or more tubes.

IIRC, flues used to be safe ended by "swaging" a new section of tubing on each end, a process in which the new tube was heated and forced over the end of the old tube. There may have been more to the process than that, but that's basically what it entailed. Safe ends have been applied by butt welding pretty much since arc welding was invented, so swaging it not a part of the safe ending process, unless it involves the firebox end of the superheater tubes in which case the new ends are swaged to the required diameter.

As I understand it, tubes have to be rolled into the tube sheets whether they're seal welded or not.

And based on what was posted earlier, was EBT using the older swaging method of safe ending tubes right up to the end?

Thanks Hugh - I was of course referring to the more modern meaning, circa 1940 or thereabouts. The older meaning is sort of like a forge weld and has some disadvantages relative to arc welding a new end on to the tube, the complexity of the process and the doubled thickness of the joint and resulting bulge being another.

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A little belated research revealed tube material, safe ending, fire sheet end flue swaging, end sheet tube expanding, beading and ring welding have been widely debated on these pages over the years. What's become apparent is that safe ending is successfully and cost effectively done not by forge welding as depicted in the E. Broad Top HAER survey rather by contemporary butt welding. Depending on new tube cost, ranging from $1.65/ft to about $4.00/ft (from these posts) and the number of tubes and flues that must be removed for access to perform the 15 year shell inspection, It seems salvage of perfectly serviceable tubes and flue pipes from lightly used museum locomotives should be considered if a boiler service shop with tube fabrication capability is available and the price is right.

From photos, WMSRR 1309 tubes and flues looked to be in near new condition on removal. Anybody know if they are being salvaged?

All tubes and flues were replaced in 2017 along with a new rear fluesheet.

DC

The EBT document clearly shows the old tube being belled and the new piece inserted into it for the 'front'. That's just the opposite of what I understood you to be saying.

Why you'd go to the same trouble and expense of doing this on both ends when you could just cut off and dress the old tube's rear end a couple of inches forward of the cut-off and previously-prossered region and use a correspondingly longer 'new piece' (which, again, appears to be explicit in the EBT document), I'm not sure I understand. Would the old tube have been grain-compromised in a way that limits its ability to be swaged and then prossered into the rear tubesheet, but not its ability to be forge-welded with high integrity to the new piece?




With one additional note: the "effective" butt-welding process involves, or ought to involve, a good full-pen weld without excessive beading (especially on the gas side) and presumably good control over the HAZ. That's not going to be particularly true of early electric autogenous welding!

But this raises an interesting question: has there been testing of modern friction-stir methods, particularly in controlled-atmosphere, to join the safe end to the old tube material? I'd think that would be quick, accurate, and far less tetchy than other methods (even something as amenable to semi-automation as submerged-arc welding). You'd probably want some sort of automatic feed to move the two ends slightly together after being raised to pyrometrically-determined correct heat range, and then keep them matched in rotation while annealing and spinning down.



Doesn't it differ by end? If I recall correctly, Porta advocated full-pen welding of the tubes at the rear sheet (where I'd also advocate careful dressing or post-machining of the joint for flow transition, whichever way the joint is belled/swaged for best gas flow vs. tube and plate cooling) with prossering at the forward end. That gets around differential-expansion difficulties with all-welded fabrication of conventional riveted/rolled boiler proportioning and construction, while ensuring that any leaks due to it are at the front end, safely blowing into the smokebox instead of directly into the firebox...

Whether you would prosser the joint before full-pen welding it is an interesting question for the practical welders here. I'd think it would set up stresses that would make good weld homogeneity difficult, but would also ensure good metal-to-metal contact without voids or the need for careful jigging.

I believe Donald was suggesting the old tubes, which looked nearly new, could be salvaged, cut down, and used in another locomotive with a shorter boiler.

It sounds like the issue with this would be certification for the old tube material. It might be possible to provide this with destructive testing of the excess material, but then you might have to do it for every tube which would rapidly eat into any savings.