Hi all,

I am in need of 140 ea 146.65" long, 2" OD x .140" wall DOM tubes for the project we are working on. Typically tubes to a British standard have been used in the past. I would like to know the US specification normally used and the best supplier, preferably on the west coast.

Thank you,

Trevor Heath
currently in Plimmerton, New Zealand

SA 178 Grade A is the US (ASME) specification for the tubes. .165 is the normal minimum wall thickness.

Wasatch Railroad Contractors can supply the tubes from the West Coast on a ship. We can also provide shipping and packaging.

Contact me via the web page listed below.

Kindly,

Greetings:
Valley Railroad recently ordered sets of SA 178 A boiler tubes for our Nos. 40 & 97 from: R-S MATCO, Inc., Oakboro, NC , 704-485-4144 (voice), 704-485-8313 (FAX), sales@rsmatco.com @$1.65/foot (price will vary depending on the total weight of your order).
We use 2"dia. X .105" wall (12 gauge) tubes.
At one time we used heavier tubes thinking that the thicker wall would extend the tube life, but have found that our improved water treatment program does the same thing and has a positve effect on the entire boiler and firebox as well.
Also, although we found that it was easier to safe end thicker tubes; "running the numbers" on cleaning and safe ending vs. buying new tubes, at this time, it is cheaper for us to purchase the new tubes. The quotes that we got for sandblasting No.40's tubes were nearly twice what we spent for No.3025's.
We considered building a tube rattler, but even then the savings would be marginal (I hate to scrap decent tubes).
J.David

Are flues/tubes normally ever DOM? Sounds like an extra cost step that provides little benefit...the ID of these tubes has no need to be precision....

Greetings:
From my days with Richard Jensen in the 60s', through Illinois Railway Museum, Steamtown and for the last 28 years at the Valley, I have always used welded tubes and flues. Being penurious by nature (and working with with people/organizations that were perpetually broke), I could never justify the added cost of DOM...
Were there problems with installation or service life of welded tubes and flues, I suppose that a case could be made for DOM, but I have yet to hear of any.
That said, if money is no object for the people/organization in control of the check book, then there is certainly no reason not to use DOM.
J.David

J. David -

If I can still remember my steel terms nomenclature, DOM stands for Drawn Over Mandrel. These would be round steel bars drawn over a mandrel while hot, making the tubes themselves seamless. These used to be more expensive than welded tubes (our company sold ERW or Electric-Resistance Welded). Strictly background information for those who may wonder about the DOM term.

Les

While recently working with the MSRR&LA at Cass, WV regarding their Climax project, I looked over the rebuild progress of shay #2. On the floor sat a bundle of SA192 seamless tubes. I asked "why not SA178?". The answer was that at some point they had cracking issues and have been using seamless now for several years in all of the engines. I never could get a more definite answer about what went wrong and why.

The critical aspect of this conversation relates to "what makes a boiler tube a boiler tube?" The simple answer to that is; a boiler tube must be flexible enough to be able to expand to a certain size (as per the ASME Code) for the thickness and material specifications of the tube. As such, a cracking issue with a tube, a 192 or a 178 will have more to do with metallurgical make-up, rather than the method used to make the tube. It is true that a 192 can be a DOM and normally a 178 is an ERW (welded) tube. However, the inspection criteria for both is stringent and both are virtually flawless.

Too often we think of a 178A as a "welded" tube. Well, in reality it is, however, it is NOT mechanical tubing, which, has a very defined and visible weld line in it and in most cases, is full of flaws. The important aspect is remembering what the process is and who it is inspected and handled in the end. Mechanical tubing, generally A36 (mild steel) is ....well.....crap to say the least and can not be used as tubing in a code vessel or a vessel that is inspected by some jurisdiction of some sort.

What causes tube cracking: Well, this is a different debate for another thread. In short, the make up of the material, the amount of copper and nickle (in combination with other aspects of the martial) can create a crack sensitive situation. Suffice to say for this conversation, the acceptable ranges of copper and nickle have changed over the years (for SA 178A tubes) and as such, we are seeing a wide range of issues in the industry. These issues can include, but are not limited to; pitting and cracking.

A short while ago there was a thread here about using thick tubes and so on. I refer back to that. Thicker tubes are a bad thing and should be avoided as there are draw backs and side effects.

Quickly:
There are several reasons that boiler tubes might crack lengthwise.
Two of the most common causes are:
1) Tube ends not annealed prior to installation
2) Over rolling either during installation or during repair (I have seen 2" tubes which were rolled into oversize holes that they had to use a 2-1/8" roller on to get tight! Yikes!)
J.David

yes we had a fairly big thread discussion on this, have to think about the old steam days and what worked for them. There might be some metallurgy refinements today that might improve things, but stick to the tried and true.

First, to answer Trevor's question:
Namasco Steel LA
Bay City Boiler SF
Seattle Boiler Works

Going down the list of comments:

Never was and never will be for locos...UP844 tubes are 2-1/4" x 0.120 wall are good to 380 psi.


Any boiler thought process that considers thicker tubes mean longer life in lieu of proper water chemistry will find out that crown sheets and staybolts corrode faster than tubes..... look at the big picture.


DOM is a structural steel term I can't remember ever seeing in an ASME Code book. The words are always "cold-drawn" or "cold-finished".


Why, J. David, your erudition is showing! You and Dave Lathrop with his "perspicacity" are in the running for the "au courant" award here on RYPN!


Nope. If the copper is more than a trace element, greater than 0.01%, it has to be greater than 0.20% and noted as "copper bearing" on the MTR. If the nickel component is greater than 0.01%, it is an alloy steel or scrap metal.


Amen! Brother Nigel.


Back in the 1950's, the SA-87 spec allowed for wrought iron or steel, welded or seamless, annealed or unannealed. That morphed into SA-178 ERW and SA-192 Seamless. Dixon Boiler Works in LA would send out 2 guys and a truck that could retube and 200 BHP Scotch boiler in one day. The boiler industry didn't have time to anneal every cut tube in every commercial boiler. Some time in the '60's the ASME changed the specs such that all carbon steel boiler tubes were required to be furnished annealed from the tubing mill.

The main reason ERW tubes are getting longitudinal cracks is the installation. People are rolling and welding tubes and crawling out of the firebox. The sharp insde edges of the tubes are exposed to furnace gasses and radiant heat. If you count every exhaust, it does not take long to roll up a million thermal fatigue cycles on the sharp edge that will find the ERW seam and start a thermal fatigue crack. The solution to the longitudinal cracking problem is to spend an extra day with an air hammer and a beading tool to knock over sharp edge of the tube.

Just to show how sinewy ERW tubes can be, take this example.

The boiler ran for 20 minutes bagasse fired before it became obvious the feedwater valve had closed. I received a call one morning about 7 from the insurance inspector for the mill telling me it melted and expect a call. I was the AI for the repair firm. When the call came at 9 am asking how soon I could get to Maui, I told them I was booked on the 11am flight.
There actually was a bigger problem than just the melted boiler. That would be 2 miles of 18" diameter rock candy wrapped in steel pipe, if they had to wait for the proper boiler repairs to flush the sugar mill. Most of the leaks were tears where the tube sections were welded to boiler supports. There were no ERW seam leaks. The Insurance Inspector and I agreed to weld the tears, hydro to 450 psi(normal mawp) and let them run for a week at 150 psi and no more than 50% firing rate of 100,000# per hour. These were 2-1/2"OD ERW tubes about 30 years old.

On locomotives, the only necessary place for seamless would be the superheater tubes.