Stainless steel boiler/exchanger?

This forum is dedicated to the Live Steam Hobbyist Community.

Moderators: Harold_V, WJH, cbrew

Post Reply
Sftyvlv
Posts: 17
Joined: Sun May 20, 2018 8:35 pm
Location: Welland Ont Canada

Re: Stainless steel boiler/exchanger?

Post by Sftyvlv » Sat May 26, 2018 5:45 pm

Trainman4602 wrote:
Sat May 26, 2018 1:23 pm
YOU
As a red seal pipe welder and a Lvl 2 welding inspector metallurgy was and is part of my training.

User avatar
NP317
Posts: 1955
Joined: Tue Jun 24, 2014 2:57 pm
Location: Northern Oregon

RN

Post by NP317 » Sat May 26, 2018 9:48 pm

Harold:
Thank you for your recommendation on the SS alloy for piston rods.
I will acquire alloy 416 as you suggest.
Appreciated.
~RN

Harold_V
Posts: 17736
Joined: Fri Dec 20, 2002 11:02 pm
Location: Onalaska, WA USA

Re: Stainless steel boiler/exchanger?

Post by Harold_V » Sun May 27, 2018 1:58 am

Berkman wrote:
Sat May 26, 2018 3:32 pm
My question was more a hypothetical, just curious how they would work. Not going to suggest going out and buying it. the average guy can't afford a 7-8k boiler for a mikado either...
I understand, not only the curiosity about if they'd work, but the price of a boiler, too.
Earlier in this thread there was a discussion about monel. You can read it by following this link viewtopic.php?f=8&t=105874&p=382147#p382147
It pretty well spells out why monel is out of the question, as material, alone, would cost more than buying a boiler made by others from steel.

My original plans were to build a northern, although I had little idea that my building project would consume virtually all of my remaining years. To that end, I took a welding class, as I wanted to be able to weld my own boiler. It is my opinion that the average guy can build one, but he must prepare himself, and certainly not expect to perform at the level of a guy who has spent years of his life perfecting his craft as a boiler maker. My two semesters of welding taught me a great deal, including how hard it is to get a weld without inclusions. Took me two tries to pass the x-ray test after working hard at perfecting the technique. That was long ago. I expect I'd struggle endlessly today.

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

Berkman
Posts: 123
Joined: Wed Aug 16, 2017 7:55 pm

Re: Stainless steel boiler/exchanger?

Post by Berkman » Sun May 27, 2018 8:14 am

Harold, thanks.

So it's more a cost issue than a problem with the actual monel material. It also seem the heat conductivity value for monel is much much lower than Copper and somewhat lower than carbon steel. Is the price of duplex SS that much more affordable ?

User avatar
Bill Shields
Posts: 5543
Joined: Fri Dec 21, 2007 4:57 am
Location: Somewhere in the World
Contact:

Re: Stainless steel boiler/exchanger?

Post by Bill Shields » Sun May 27, 2018 8:22 am

monel makes very good piston rods also....
Too many things going on to bother listing them.

BClemens
Posts: 389
Joined: Sat Oct 08, 2016 10:04 pm

Re: Stainless steel boiler/exchanger?

Post by BClemens » Sun May 27, 2018 9:05 am

Harold_V wrote:
Sat May 26, 2018 3:10 pm
NP317 wrote:
Sat May 26, 2018 9:43 am
What stainless steel alloy would be best for piston rods?
We're rebuilding a sorely abused Locomobile motor for the WAAAMuseum in Hood River, OR.
~R
Pretty much any stainless alloy will serve, but the 300 series tends to be easy to gall, so I'd avoid them unless I had no alternative.
Of all the stainless alloys, 416 is the easiest to machine, and yields a great finish. It is also capable of being heat treated, unlike the 300 series of alloys. If I had the option, I'd likely choose that alloy, and heat treat the rod, which enhances its corrosion resistance and would extend its useful life (less wear).

You could also consider the use of 17-4 PH, although for what ever reason, the maker instructs that the material should not be put in service in the solution annealed condition, but should be heat treated. It can be machined in the H1000 condition, or even greater (H1250), but you'd likely enjoy success even in the H900 condition. It's tough, but it will machine.

Bottom line? I'd still shoot for 416.

H
Mcmaster-Carr to the rescue - check their inventory for 'Stainless Steel Shafting'. They list 17-4 through hardened (though to machine or thread) and surface hardened 440C in many common sizes. Ideal since it will not corrode and it's hard as the HOH.

Dave, Interested in how your SS boiler is constructed - TIG? Apparently Monel 400 is so very hard to even find in the US and also purchasing a minute quantity anywhere, so copper and stainless (or steel) will be the only alternatives. I went in hot pursuit of a piece of 8" dia. Monel 400 pipe and found none in the US (unless large quantity) and Monel 400 sheet is next to impossible to acquire. Maybe my pursuit was in the wrong direction? Also; the Brits often put a copper firebox and flues in steel (or SS) boiler shell.....?
BC

Harold, 'special characters' (Alt) no longer work on the site. Diameter: Alt-0-2-1-6 will kick you off site.

Harold_V
Posts: 17736
Joined: Fri Dec 20, 2002 11:02 pm
Location: Onalaska, WA USA

Re: Stainless steel boiler/exchanger?

Post by Harold_V » Sun May 27, 2018 4:00 pm

BClemens wrote:
Sun May 27, 2018 9:05 am
Harold, 'special characters' (Alt) no longer work on the site. Diameter: Alt-0-2-1-6 will kick you off site.
I can't help but think that's a problem more related to your computer (or other device) than it is this web site. I've had the same experience on more than one occasion.
Ø (alt 0216) seems to work just fine for me---at least right now! :D

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

Harold_V
Posts: 17736
Joined: Fri Dec 20, 2002 11:02 pm
Location: Onalaska, WA USA

Re: Stainless steel boiler/exchanger?

Post by Harold_V » Sun May 27, 2018 4:08 pm

Berkman wrote:
Sun May 27, 2018 8:14 am
So it's more a cost issue than a problem with the actual monel material. It also seem the heat conductivity value for monel is much much lower than Copper and somewhat lower than carbon steel. Is the price of duplex SS that much more affordable ?
I have zero experience with duplex SS, so I am unable to address that question, but, one thing I believe (the world according to Harold), is that anything you can do to address corrosion in a boiler is worthy of investigation. Especially if one is young and expects to enjoy this hobby for a long time. I'd much rather spend my time building another engine that endlessly rebuilding one I had built previously.

But then, that all depends on one's interest, eh? Some folks want to "play trains" and expect maintenance to be very much a part of how they spend their time. For me, that's not the case. Speaking as a retired machinist/toolmaker, making projects in metals is more a display of my craftsmanship--the ability to ply my trade with a high degree of success. Said another way, to me (and I do not speak for anyone else), it's not the arrival, but the journey that's important. Building, to me, is far more interesting than running. Especially if one is limited to the same short track without features.

Again, the world according to Harold. There is no right or wrong---just personal preference.

H

Edit:
Be careful when you pursue exotic materials. I had the occasion to quote a job for Litton Industries, many years ago. In that project was a material requirement for a small piece of Invar 36 (about a square inch of material). It was available, but one had to make a minimum purchase of a square foot, and it cost "only" $1,000. I addressed the issue by requiring Litton to provide the material, which I would machine.
Wise people talk because they have something to say. Fools talk because they have to say something.

BClemens
Posts: 389
Joined: Sat Oct 08, 2016 10:04 pm

Re: Stainless steel boiler/exchanger?

Post by BClemens » Sun May 27, 2018 4:34 pm

Ø - OK hardware issue - fingers

User avatar
John_S
Posts: 709
Joined: Wed Apr 06, 2011 8:21 pm
Location: Cumming, GA

Re: Stainless steel boiler/exchanger?

Post by John_S » Sun May 27, 2018 6:34 pm

My two cents: Save your money, build your boiler from a good piece of pipe and 516-70 carbon. It will outlast any savings you'd gain by spending 5x as much on stainless.

Sftyvlv
Posts: 17
Joined: Sun May 20, 2018 8:35 pm
Location: Welland Ont Canada

Re: Stainless steel boiler/exchanger?

Post by Sftyvlv » Sun May 27, 2018 11:04 pm

John_S wrote:
Sun May 27, 2018 6:34 pm
My two cents: Save your money, build your boiler from a good piece of pipe and 516-70 carbon. It will outlast any savings you'd gain by spending 5x as much on stainless.
Good recommendation.

Sftyvlv
Posts: 17
Joined: Sun May 20, 2018 8:35 pm
Location: Welland Ont Canada

Re: Stainless steel boiler/exchanger?

Post by Sftyvlv » Sun May 27, 2018 11:21 pm

As if this hasn't been mentioned already. Use good joint prep on all groove and fillet welds. Be careful and know your material and know how to weld.
Had our local inspector investigate a case where a "backyard" distributing manifold for compressed air was fabricated. A summer student employee walked beside it and took half his face off. That was with 90 lb plant air.

Post Reply