Boiler restoration or retirement

[KC6UVM]

Rather than hijacking another thread, I thought I'd start a new one *discussion*

It's been over a decade since I acquired this vertical boiler. A while back I thought I'd take a closer look at it and see if it would hold water and hydro the thing. To make a long story short, water leaked out of the tubes at city pressure.

A short description: The boiler is just the vessel, no firebox and smoke box, stands about 38" tall, 16" in diameter and has 41 tubes swaged into it having an id of about 1.125". Stampings on the boiler say it was manufactured in 1969 and it has an "M" stamp.

To start with, I'd like to remove the tubes. I bought some thick 1" diameter cutoff disks and mandrel which will fit inside the tubes (from McMaster) but my Moto tool doesn't spin fast enough to make a dent in the tubes (probably steel). I also lack an air supply for my air tools to try my die grinder (does 20K rpm). Can anyone recommend cutting tools to take out tubes? ???

Second thought is to retire the boiler, considering its age (for the sake of safety). I thought I'd hide a small air tank and compressor in the gutted out boiler. Outward appearances, the remaining tube would look like a boiler, but provide compressed air for air brakes and a steam whistle.

What do you all think?

George

 

[Kaleb]

If the boiler is brass or copper, it would be quite safe, the operating pressure depending on the wall thickness and staying. If it's thin steel, don't even think about steaming it. If it's thick steel, it should be right for a while.

 

[steamer]

The Code "M" stamp probably means its an ASME Code Miniature boiler. That at least means to me it was safe at SOME point in time. There should be a build number that goes with the stamp.

Take a picture of the stamp and any numbers....It should be identifyable.

We're are the leaks?...

Tread carefully here...that's a big "miniature" boiler....though I am very glad your trying to hydro it and do the "right thing"

I have not cut tubes out, but would suggest that the Steam Loco guys here would probably give your the proper direction for that.


Dave

 

[GWRdriver]

. . . it would be quite safe

It is not possible to declare that this boiler is safe based upon the information given so far, and brass is a very poor, and potentially dangerous, material for boilers.

As to retiring the boiler, even with new flues a hydrostatic test will only tell you if it will hold cold pressure today . . . it won't tell you anything about the condition of the metal. If you don't know the history of the boiler, or its treatment before it came into your possession, a severe weakness could exist which a hydrostatic test won't reveal. On the other hand, it could be like new. For starters a visual interior inspection is needed and beyond that there are ways of testing to determine the thickness of the shell metal. A boiler shell can be "mapped" for thin areas.

As to whether to retire the boiler, I think two questions need to be answered: Is it safe (obviously)? and Will it suit my intended purpose? The detemination of safety should be based upon what you know (or discover) about its physical soundness. That might be determined by inspection and testing, and it might be that you say it looks OK to me, or I know where it's been, and gamble that it is sound as-is. The intended operating pressure would bear upon this decision as there would be a great deal more hazard at say 100psi than at 10psi. And then there is whether a new boiler designed specifically for your intended use would be more efficient and cost effective, all things considered.

 

[GOOFY063]

George, sounds like plan B would be your best bet. Thm:

 

[steamer]

Actually, I wouldn't do that just yet.

I would get the serial number for boiler and talk to the state boiler inspector. He should have a record of the last inspection...if it was 40 years ago....well that's a data point...if it was 2 years ago...that's another data point!

Dave

 

[KC6UVM]

Thanks for the comments. :big:

Boiler is all steel, must have been used in some commercial fashion where it might have been bolted into some sort of stationary plant. My original idea was to convert it to a mobile vertical fire tube boiler to go aboard a 2.5" or bigger NG Clishay. But as I'm more concerned about it's age (and safety), the plan B of faking a boiler with internal air tank and compressor for a battery electric Clishay at the moment (sorry steam guys) is the better idea. I'm going to need air for brakes (if I'm hauling public) and the whistle. The 6" brass bell is electric. And I'm using a 2 HP baldor motor that came out of an electric fork lift. This beast of a boiler (intact) weighs approx. 400#s. I'm going to hunt around the North Los Angeles County area for a shop that has a large horizontal band saw that can handle the 16" diameter boiler and remove the top of the boiler below the weld and cut through all the tubes at once. A plasma torch would be a messier job. :-*

My 2.5" NG Clishay is the subject for another thread when I have time. The trucks are almost finished lacking #40 chain because I can't find my chain breaker. A 19" by 67" frame is almost done.... th_wav

I do have plans for a couple types of vertical fire tube boilers when I do get around to converting the engine to steam. One is a Martin Evans design (10" diameter by about 18" tall) that I bought from Model Engineering Magazine of the UK. It looks easier to adapt for a future steam version of my 2.5" NG Clishay.


George
Lancaster, CA

 

[GWRdriver]

This beast of a boiler (intact) weighs approx. 400#s.

George,
Good grief!! That is a beast, and this weight suggests to me that it has a relatively thick wall and heads, and if they are thick enough at the thinnest point there may be years of good life left in the shell dispite having some corrosion.

I do have plans for a couple types of vertical fire tube boilers when I do get around to converting the engine to steam.

If I was doing it, before I cut any metal I would work backwards from the engine unit and figure its steam consumption and size the boiler to that. The last thing you want is to end up with a boiler that won't steam your engine under the conditions it's likely to face. Guys hate it when someone is dead on the main for lack of stem.

 

[KC6UVM]

GWRdriver,

The steam motor I'd like to use is a Tiny Power W (twin 2" dia by 2.25" stroke). It is rated at 3 HP.

http://www.tinypower.com/store.php?...il&PHPSESSID=2a0ec6fb6a8d2892c3537a0bbfdafb10

If I figure a factor of 2, I'll need a vertical boiler capable of doing about 5 to 6 HP so I don't get stuck somewhere on the railroad w/o steam.

Without regular work, I have to settle for what I have for now and keep from over spending past my budget. :'( I work on-call for a local school district as a high school substitute teacher and I'm working towards a second BS/MS in engineering at a nearby University.

I have a motor and controller. I figure I'm a go (to get some work done in the shop) when I get some of my Diffy Q and Power Electronics homework done. :bow: 30 years later and I wish I'd finished off all of my calculus classes.

The boiler, as it is, has significately no water leg and wasn't meant to be used as a hobby boiler. I don't plan on destroying the shell, It'll be reusable some time in the future. I'd rather modify the Martin Evin's design for the steam capacity I'll require. Just got in a copy of Power Boiler Design by Malek from Amazon today. Hopefully it won't put me to sleep like my thermodynamics book used to do....


George

 

[steamer]

You'll need at least a 100lbs/hour for the tiny power unit.

About 30 square feet of fire tube boiler

Dave

 

[KC6UVM]

Thank you everyone for your comments and advice.
I'll keep it in mind.

George

 

[ianjkirby]

Hi George,
I certainly don't wish to pour water on your plans, but I think you should know that the idea of using compressed air instead of steam may leave you a little short. Compared to steam, it has no thermal energy, which is where steam gets most of its useful energy from. I seriously doubt that you will be able to compress air as fast as your engine unit will use it. If your engine is 3 hp, then I think you will need to run at least a 6 or 7 hp drive motor to the compressor, as the efficiency of air compressors is quite low. An awful lot of the input energy is simply lost as heat, which cannot be stored in the air and redrawn. At least talk to a local compressed air company or specialist before you spend too much money!
Regards, Ian.

 

[KC6UVM]

Hi Ian,

Some days I feel like I'm treading water in the deep end of the pool. The boiler I'm restoring will first hold an air tank and compressor till I can rebuild it to provide steam some day. I think the shell is OK to be reused. I won't know what shape the shell is in until the tubes are removed and the boiler is cut open. This beast is over forty years old. For now, I'm planning on using the shell to fake a vertical boiler.

The engine I'm building (a 2.5" ng version of a chain driven Clishay) will be first built as a battery/electric chain drive. The air system will be just for a whistle and air brakes only. The clishay also has a hand brake on one of the idler shafts if I don't get the air brake system up and going. The batteries will be hid in the water tanks. I haven't figured out how to hide the electric motor (yet). The motor is about 14" long by 9" in diameter and was pulled out of an electric forklift.

Later on down the road, when finances are better, I'm working regularly, can afford to build/buy a steam motor (the list goes on) and restore the boiler to working order, the clishay will then work and run on steam power as originally intended. The frame is almost done and when the chain breaker arrives from McMaster-Carr this week, I'll install the chain in the boggies next weekend. There will be pictures for a new thread soon. ;D

 

[KC6UVM]

I know it's better late then never, oh: If anyone is interested, I snapped some fotos of the boiler.

George

 

[Dan Rowe]

Hi George,
If your intention is to restore the boiler to ASME code then I do not believe that can be done in a home shop. Just as it takes a shop with the certified credentials to build an ASME code boiler a shop has to have the proper paper to repair an ASME code boiler. If that was your intent I would look into finding a shop who can repair it to NBBI inspection standards and apply a code R stamp to bring it back to ASME code compliance.

Dave what did you use for the RPM for the 100#/hr steam consumption figure? Locomotives usually turn slower than marine engines.

Dan

 

[KC6UVM]

Dan,

I'll keep your info in mind. As a DIYer, and finances aren't exactly good right now, the boiler can sit in a corner in the garage out of my way. I'd like to do as much as I can w/o bringing someone else aboard unless absolutely necessary.

If the shell is good, I was thinking of reusing the shell using the attached plan.

My next big purchase will be batteries.

George

View attachment Vert-Boiler.pdf

 

[Dan Rowe]

Hi George,
I recognize that drawing because I drew it. The dimensions listed are for smaller of the two vertical boilers listed in the 1884 Shay catalog. This was the 7 ton Shay with 2-7"x7" cylinders. The number of 2" tubes is 125.

The type of boiler is known as submerged tube or submerged head. Some of the internal details were borrowed from the 1907 ICS book "Boilers Types and Designs".

The facts are simple vertical boilers are very wasteful. They burn a lot of fuel for the steam they produce no way around that unless you want to make it look like a smoke stack. The simple construction makes a low cost boiler and they are still built today for similar reasons.

The reason submerged tube boilers were considered better is if the fire is forced on a normal vertical boiler the danger is the tubes will get red hot and collapse. The submerged tube boiler design was considered superior because it eliminated that danger.

It is all about heating surface with a vertical boiler. Harris tells us that this type of boiler will boil 1 cubic inch of water for every 100 square inches of heating surface. Design No 5 in the appendix of Harris is a multitube boiler like the steel one in this thread only with a 3" copper shell. It has 37 tubes with the water 2/3 of the way up the given H.S. is 60 sq in. I just drew a 3/4" scale version the larger of the 1884 Shay boilers using a 3" copper tube and a submerged head I used 6 less tubes of the same size and got 71 sq in of heating surface. I will loose a bit for a fire door but I will still have more H.S. then design No. 5 so I am happy with the numbers.

Dan

 

[KC6UVM]

Dan,

I'll have to give credit for which credit is due. Thank you for your work.

I'm still learning about boilers and their design. I picked up Malek's book on Power Boiler Design... and I have the other model boiler books in my collection I've been reading. Getting into this size takes me out of the region of what ASME considers a "model boiler" if I exceed 10 cubic foot of boiler tubes. Money is tight and I figure I can take my time to work out a vertical boiler design for this type of engine. Bob Maynard used a water tube boiler in his original Clishay design (which I understand may be less efficient, but I could be wrong). There is plenty of time to find a working plan. I think a propane boiler would fire the cleanest but I understand there are drawbacks on the propane delivery as the gas flows and freezes requiring multiple tanks. When finances improve, I'll steamify this engine or move onto another project.

Thanks,

George

 

[steamer]

600 rpm.....1.5 x 2.5 .....150 psi...saturated.....full stroke cutoff for some condensation allowance


ie my boat engine ;D

Dave

 

[KC6UVM]

Eventually there will be a twin vertical steam engine on the CliShay. I plan on designing a mounting plate that will interchange with the electric motor base.

I'll also have to consider the fact the electric motor rotates up to three times as fast as most steam engines. So, I'll have to reconfigure the gear reduction when the time comes. ;D

George