Would appreciate some info/thoughts/experiences with welded tubes and flues versus seamless tubes and flues for steam locomotive boilers.

Grant,
The welded flues are just fine and will outlast the 15 yrs, 1472 service days. Save your money and the welded seam flues are easy to get.

15 years??? Isnt it 5 years? I know here in New Jersey we have to retube our boilers every 5 years.

-Eric

Adam is referring to 34 CFR Part 230, which mandates that the flues be pulled so that the boiler shell can be reinspected and a new Form 4 calculated. This must be done after 15 years or 1472 service days, whichever comes first. So, 15 years is the maximum time you can go without pulling the flues. It doesn't have anything to do with the condition of the flues one way or another; they just have to come out to get at the boiler.

Of course, depending on operating conditions you might erode the flues and have to replace them a lot sooner, which is apparently your experience.

Under FRA regulations the tubes have to be removed as part of the 1472 day inspection. This inspection is required after 1472 service days or 15 calendar years, whichever comes first. FRA regulates the boilers of steam locomotives on the general railroad system, and those who meet certain criteria that makes them a 'non-system, non-insular operation'. The local jurisdiction, usually the state, regulates boilers that do not fall under the FRA.

I agree with Adam, the welded tubes are fine, as long as they cnform to the proper specification, which is ASTM SA-178, if I recall correctly.

OO ok well NJMT isnt FRA so we have to follow state rules and we have to re-tube our boilers every 5 years.

-Eric

I was once shown a welded water tube from a stationary boiler that had gone without proper water treatment, and it had corroded quite dramatically at the seam only. But this was a WATER tube, and an example of the speed with incorrect water treatment can destroy a boiler. I think that without proper water treatment, oxygen pitting will attack your boiler tubes all over. There is no reason to use seamless tubing in a locomotive.

But am I imagining things, or do I recall that the pitting is worst on the upper surfaces, and the seam should be installed at the bottom? Can someone revive my memory or correct me on this?