Hi folks,

Disclaimers first-I don't claim to be a 'steam guy', keyboard commando, etc. My nephew sent this video, and I'd like to get the reactions of the knowledgeable folks here. Is this a good educational/overview video on boiler tube installation?
https://www.youtube.com/watch?v=u7UQKNapTBE

Thanks for your time,

JD

It covers the basics very well - bear in mind this is an industrial rather than locomotive boiler.

Same disclaimer!
Have helped with a few tube replacements on traction engines. Not sure how that translates to railroad, likely much the same.
The video seems to have the basics. To add, cut each tube to size, because the lengths can vary slightly. Also, if beading, do not leave too much material at the ends because it makes the beading process harder to do.

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"Rolling In" copper ferrules isn't done anymore? I never saw the point in it myself.

Why are some front sheet tubes and flues left unbeaded and unrolled if the concern is heat transfer?

"Why are some front sheet tubes and flues left unbeaded and unrolled if the concern is heat transfer?"

Because the primary location for flame and hot gas impingement on the tubes is at the firebox tubesheet. Usual practice is to flare most, if not all, the tubes in the front sheet, and to bead a pattern of them to help hold both the front and rear tubesheets in alignment.

With the larger superheater flues, they are rolled, flared, and beaded at both ends.

Howard P.

It is still done, particularly in a circumstance where a tube hole is slightly too large, and rolling a tube into it will result in an over-rolled tube. A ferrule will make up the difference. The tube hole is tested for cracking beforehand, of course. Some boilers/tube sheets have had the tube holes made larger in design to accept a ferrule. When the tubes are replaced so are the ferrules.

Locomotive boilers also tend to have the "king hole", a tube hole which was enlarged purposely to remove the other tubes through it. This hole will pretty much always have a ferrule in it. When tubes are covered in scale or have slag from being cut, having a slightly larger hole to get them through is a saving grace.



This is, imo, best practice. But outside of the locomotive world I rarely see polishing tube-ends done. The tube holes, on the other hand are polisjed to clean up any slag and in preparation for welding up torch nicks, as well as part of preparation to have the sheet dye tested for cracking.



This could depend on what method will be used, whether beading, welding, or belling. So I understand them leaving that out. Also of note is that wide adoption of inside tube-cutters (a tool in wide use outside the locomotive world which I don't understand why it hasn't gained traction, along with bead-rollers, aside from of course the upfront cost, which pays for itself tenfold in saved time over the tool's life) eliminates the need to pre-measure tubes. Just get a general length, rough cut the tubes an inch or two long, set and roll one end of the tubes, inside cut the other, and every tube will be ready to roll and proud of the sheet the exact same amount.



They can be either uphill or down, depending on the WPS for the shop in question. I've seen welders run a full circle around a tube in one pass- half uphill and half down. Welding upwards will (generally) result in better penetration with a 60xx electrode- but penetration isn't necessarily the game seal welding tubes, as the rolling of the tube forms the pressure seal.

Just in my experience.

I am in this shop almost every week, for one thing or another (I'm a state inspector).
No, this is not railroad. No, copper ferrules are not used in the commercial world, and nobody knows what they are. No, commercial boilers don't have a "king hole".

This shop produces many videos about all kinds of boiler related topics, and across the street they have a full time "Boiler University", which offers classroom instruction and hands on learning for students of all kinds. Many boiler contractor companies send their employees to this school

It is a professional shop, and also has a rental boiler fleet numbering in the hundreds spread all across the continent.

I live about 5 miles away from them.

No disrespect, but my experience working on stationary/commercial boilers says otherwise. Note I specified locomotive boilers with regard to king holes. Commercial boilers don't have them, no.

Might be important to note here that locomotive boilers are worked much differently than industrial boilers in terms of both intensity of service and variation of intensity of service. The late and very much missed Dan Ranger told me about a new boiler he had fabricated for RCBT - kept having staybolt issues. The engineer for the boiler works that built it came out a rode a trip and was amazed at the cycling and work of the locomotive and its impact on needed steam generation and how it varied very quickly - reengineered the stayed surfaces, repaired it and solved the problem. So, while copper ferrules and king holes are very useful for locomotives, industrial boilers not likely to need tube jobs frequently and tubes tightened after starting to leak in service can be better standardized in simplicity without risk of loss of service.

It is fascinating to watch the video, read through the comments there, and then see the locomotive-specific discussion here.

The 'specified' distance the tube is left proud for sealing/beading is mentioned in one of the comments as 3/16". (I presumed this was for the stated firetube material and dimension, in a multipass commercial boiler at the first reflected pass. A couple of comments discuss the type of material used in the flues in these applications.

A number of comments concern the use of long Collins expanders in re-rolling the section of tube which is 'proud' and has been seal-welded as indicated -- the concern being that it may cause cracking in the seal-weld metal or whatever HAZ there may be that could induce stress raising into the tube end or sheet. Apparently some foreign practice is not to re-roll the 'end' 5mm or so of the seal-welded tube, and this might be done in practice with an expander with cylindrical in place of prossering rolls.

Is there any point in using bore gauges or go/no-go gages after both the prossering and the re-sealing passes? Would you need multiple sets to accommodate periodic recutting/repolishing of the seats in the tubesheet?

I thought 'king holes' were only appropriate for all-firetube boilers, as I'd think normal practice in any boiler shop capable of safe-ending would be to remove even the most corroded or warped tubes through one of the superheater-flue openings in the sheet...

But how do you get the superheater flues out? King hole!

I don't remember ever explicitly seeing a 'king hole' for flues. That's not to say there wouldn't be one.

But I'd think a flue would safe-end about as easily as a tube, so removing one 'on spec' to be able to remove any tube, no matter how corroded, about as quickly as you could use an internal cutter at both ends would be better than any 'needs a specialty ferrule or larger expansion' merely tube-sized king hole.

Wouldn't the 'worst deposits' be on the tubes toward the bottom of the shell, far away from where I'd envision a 'king hole' would be located?

I would dearly love to ask how the tubes and flues were removed from a certain modern locomotive after a certain swimming-pool-chemical contretemps. But it's borderline trolling even mentioning the incident on here, let alone asking to rehash how it was or woulda-shoulda-coulda been handled...

The king holes I've been fortunate enough to take advantage of are low and center, but not at the absolute bottom row of the tube sheet. I do wish they had caught on in the industrial boiler world. The worst tube scaling I've seen tends to be by the injector inlets and along the bottom couple rows of tubes toward the front of the barrel, farthest from the common blowdowns locations. You can wash up there through a belly plug, but just washing usually doesn’t get the hard, tough scale deposits that build up there.

Your experiences may vary from my observations.

I felt the tutorial was fine. NO it did not go into every possible scenario, but it was a tutorial not a course taught at the "college". Though it is interesting reading all the f/u responses. I like this kind of thread over who we can "brand as evil" threads.

I wanted to hear about copper ferrules and I was rewarded. I know of only one locomotive that had originally had copper ferrules, the D&R #9 at M-C museum. A mistake was made and the flues were ordered before the old ones were cut out. So they were installed without any. I do not remember the years but am thinking early 1970s? Could of been later but think it was early 1970s. I do not think it worked that well as I believe they had to be tightened up, eventually in the end didn't last near as long as they should of. It has been out of service for many years now and think those tubes are still in her? Was told they would of put them in had then known before ordering the pre swaged ends. Not sure how accurate my memory is about all this but it is as I recall it. Someone can correct me if needed?

When I was in high school I helped remove and replace one solitary flue in a vertical boilered steam crane {AO Smith}. It was a job and it fought us most of the way. Frankly I do not remember how we got it started but the scale and rust made it a difficult adventure. I had asked the boiler inspector {Virgil} how would you retube a boiler like this? I had to run a hydro on the boiler for him to ok it back into service. There was no king hole that was obvious so he said he would cut a small section between tube holes for quick access and weld it back into place when done. This was the flue sheet up on top side, not firebox end obviously. Later I punched all the oil sooted tubes and the boiler was good for many years till it was scrapped by MC. Being in high school I enjoyed the experience. Disclaimer I was not the lead man in changing out the tube, that was Dave W. I did meet with inspector and completed the hydro on this crane and another crane at that same appt for some reason I was available during the work week.

Regards, John.