Stainless steel boiler/exchanger?

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darjeeling
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Joined: Sun Jul 28, 2013 3:43 pm

Re: Stainless steel boiler/exchanger?

Postby darjeeling » Mon Oct 16, 2017 3:42 pm

Trainman4602 wrote:Doug's locomotive is still running. There are two other noted locomotive around with all stainless steel boilers. That would be Tom Millers Big Boy now in New Zealand and Dave Moor's Challenger. My K4 has stainless steel flues. There is nothing wrong with stainless steel in model boilers.

This subject has gone around on this forum many times.


The Tom Miller Big Boy is now SGS commercially certified here in New Zealand, together with an 8" 2205 Duplex S/S boiler. SGS is known the world over for strict building and inspection procedures. Big Boy has also had its first track trials on 7.25" gauge track here in Tauranga.
We also have a very large Briggs boiler refitted with a Duplex 2205 heat exchanger after corrosion problems with the original carbon steel one. Although this is not certified to date. There are about 40 Duplex boilers operating down under at this point in time.

John Heald

darjeeling
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Re: Stainless steel boiler/exchanger?

Postby darjeeling » Mon Oct 16, 2017 3:55 pm

For those interested in Big Boy, most of the freight cars purchased with the engine have also been regauged and may be seen with the engine in the coming months.

John Heald

BClemens
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Re: Stainless steel boiler/exchanger?

Postby BClemens » Tue Oct 17, 2017 5:46 pm

michaellynn2 wrote:Folks , I have no experience with stainless boilers except one. A boiler inspector in the state of VA. told me he would never pass a boiler that he would inspect made of stainless.


I would think that this inspector may need to do some homework. At least he shouldn't make that little mind up so early in the morning.

By 'silver soldering', what is meant is not 'silver brazing'. The eutectic silver containing alloy is not the brazing alloy that is most popular which requires 'red heat or greater than 800°F to flow. There are lower melting 'liquidous' silver bearing alloys made and used with temperatures well above the working temperature of a 100 - 125 psi steam boiler. This solder has been being used for probably 40 years or so. It works with copper, steel, stainless steel and other metals and combinations of them.

Way back when this 304L pipe was purchased for a welded boiler, I was unaware of the pitfalls of the 'heat affected zone' corrosion brought on by the use of cholorinated water for steam production. The decision was made to discard the very idea of a welded stainless steel boiler - even though since, I have read about completely sucessful boilers of 304, 316 and the new on the scene (in other countries) duplex stainless steel. But then it is still unaccepted in the US. Even considering the use of 'silver SOLDER' or the use of distilled water - "there will be no Stainless Steel boilers run on 'my track'" "Let's over build our boilers out of heavy walled welded steel pipe and boiler plate." Most boilers built today could probably be tested to 1000 psi - but then they rust, corrode and deteriorate in a few years so your time, money and energy invested in your 'live steam locomotive' is a waste in just a few years. Welded copper is out - welded stainless is out (rightly so) and silver soldered stainless is out too.

I seriously believe this topic is totally exhausted.... copper is in the works but my wife says go ahead and get the monel 400 for the next one. No discussion required!

BC

Harold_V
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Re: Stainless steel boiler/exchanger?

Postby Harold_V » Wed Oct 18, 2017 1:43 am

BClemens wrote:... copper is in the works but my wife says go ahead and get the monel 400 for the next one. No discussion required!
BC

You'd be well served to hang on to that woman! :wink:

It was my wife who suggested I purchase the Haas CNC toolroom mill I own.

I'd love to hear the details when you acquire the monel. Everything I've learned dictates it's killer expensive.

H
Wise people talk because they have something to say. Fools talk because they have to say something.

michaellynn2
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Re: Stainless steel boiler/exchanger?

Postby michaellynn2 » Wed Oct 18, 2017 9:08 am

This topic is well exhausted but the code is the code. The small thinking inspector stated, " what a person builds for their use use is their option. When a boiler is operated in public the code stands."
michael george

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SteveR
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Location: Los Angeles

Re: Stainless steel boiler/exchanger?

Postby SteveR » Wed Oct 18, 2017 9:01 pm

Not exhausted at all.

You make it sound like it's either Monel or CRS. You only need a thin protective layer. Has anyone had the inside of a boiler plated?

SteveR
12x36 Enco Lathe, 9x42 Bridgeport, SMAW, O/A, Miller MIG w/gas, "Tools to make things"
1.5" Allen Models Consolidation in progress
1" FEF in progress
1" LE Pacific "Project"
3/4" LE Northern Project

BClemens
Posts: 292
Joined: Sat Oct 08, 2016 10:04 pm

Re: Stainless steel boiler/exchanger?

Postby BClemens » Thu Oct 19, 2017 1:35 pm

SteveR wrote:Not exhausted at all.

You make it sound like it's either Monel or CRS. You only need a thin protective layer. Has anyone had the inside of a boiler plated?

SteveR


You are absolutely correct - not exhausted at all.... TIG welding and silver soldering Copper was mentioned as well as stainless but no mention was made about a CRS boiler. Cold rolled is good for bolted assemblies but not so good for welding 'cause it will warp wildly.

Plating....there's an idea! How about fabricating a copper boiler out of say: 1/8" sheet then anneal the whole thing real good. Then build a steel boiler over the copper one and hydro form the copper inside of the steel..... A copper lined steel boiler....

To get back to some seriousness - plating the inside of a steel boiler makes sense but would probably be as expensive as building a copper boiler.

BC

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Builder01
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Location: Erie, PA

Re: Stainless steel boiler/exchanger?

Postby Builder01 » Thu Oct 19, 2017 7:50 pm

If you are making a 1" scale boiler, when you make it out of 1/8" sheet copper silver soldered (as mentioned above), you are done! No need for steel of any kind. But, then, this is an old idea, as boilers in this scale have been made this way for decades. It is not stainless steel, but, works quite well and is time proven. Nothing to invent or experiment with.

David

BClemens
Posts: 292
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Re: Stainless steel boiler/exchanger?

Postby BClemens » Thu Nov 02, 2017 5:37 am

Anyone interested in the monel 400 boiler concept? - so: we knew the material is expensive so here's the first quote:

CONTINENTAL STEEL & TUBE
can offer as follows:

Alloy 400 B/SB165 UNSNO4400 – Pipe

6”Sch10 x 3.1667FT @ $289.28/FT

1PC @ $916.06

Approx. 33.02LBS

This is a 38" piece of 6" pipe - 6.625" OD - (Sch10 = .134" wall, so actually Ø6.357 ID x 38") is $24.11 per inch or $27.74 per lb.

Then there is the monel 400 plate stock..... The TIG/silver soldered copper boiler has become quite 'adequate'. Definite toss-up between longevity and that other idea... The response to these prices was "whaaaaaattt?" We have already started on the copper boiler.... :roll:

BC


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