Boiler Build For American LaFrance Engine

[JorgensenSteam]

Use this button

 

[steamer]

Hi,

Like Pat said its under the "Modify" button..I believe you have 24 hours....


Dave

 

[steamin]

Thank you gentlemen, if it were a snake it would have bitten my right pinky off. Try as hard as I can to proof read before I post, there seems to be a mistake in content or just plan wording.

 

[Jasonb]

I'm going to have 100psi.
Do you think these tubes would have a thick enough wall thickness?

Giovanni we have said on numerous occasions to do proper calculations for your boiler not just hope someone elses choice of tubes/plate/barrel will suit your boiler. If you were overhere you would have to show these calcs to the boiler inspector as its an unproven boiler design (in model terms)

J

 

[Jasonb]

Steamin you may find this interesting, we don't usually bead over the tube ends though.

[ame]http://www.youtube.com/watch?v=LCz3dK0tC-A&feature=player_embedded[/ame]

J

 

[steamin]

JasonB, thanks a lot for the video link. Yes, it was interesting. About 5 years ago, my wife and I went to a steam school at the Denton Farm Park, NC. We had the opportunity to plasma cut some tubes out and then go through the process on installing new ones.

I totally agree with you on boiler calcs. I had to furnish them to the state of North Carolina Board of Labor for the build of my 1/3 scale CASE 65. I found some great stuff at the state of Maryland Boiler Division for calculating everything but the flue tubes themselves. I have gone through my two booklets on building "model" copper boilers, but found no mention on how to properly size flue tubes or how to calculate the other boiler parameters. I have several drawings for model copper boilers that specify a certain size of flue tube but I have no idea how they came to that size.

For the LaFrance, I am making an all steel welded boiler, which is inherently stronger than a copper silver soldered boiler. Instead of steel flue tubes that I have used in 4 other boiler fab jobs, I want to roll in 5/16" x 0.028" thick wall hard copper seamless tubing into 0.250" thick tube sheets. The original plans called for 3/8" x 0.035" wall copper flue tubes. Dropping down to 5/16" diameter with a slightly thinner wall does not give me a great deal of concern. If I should be concerned, please someone wave a RED flag.

 

[Jasonb]

Those tubes should be fine, my current traction engine has the same size though soldered into 0.128" copper plates and rated at considerably more than your 60psi (don't want to say what as others need to do calcs).

Harris's book gives some advice on size & number of tubes, if you don't have it there is a link to it on-line in the other boiler fab thread. My only thoughts may be with you wanting a wood burner they may soot up a bit faster in teh smaller sizes but it not as though you want to run it all day so a good sweep after each session will be fine and not too much resinous pine.


J

 

[steamer]

Thank you gentlemen, if it were a snake it would have bitten my right pinky off. Try as hard as I can to proof read before I post, there seems to be a mistake in content or just plan wording.

Ahhh no worries ...wait till you've done it a couple dozen times and becomes old hat! ;D

Dave

 

[Dan Rowe]

I totally agree with you on boiler calcs. I had to furnish them to the state of North Carolina Board of Labor for the build of my 1/3 scale CASE 65. I found some great stuff at the state of Maryland Boiler Division for calculating everything but the flue tubes themselves. I have gone through my two booklets on building "model" copper boilers, but found no mention on how to properly size flue tubes or how to calculate the other boiler parameters. I have several drawings for model copper boilers that specify a certain size of flue tube but I have no idea how they came to that size.

Larry, yes I agree that finding a formula for sizing a model boiler flue is not easy. I assume you read the thread on this topic. It is a complex problem because tubes with external pressure do not fail in the same mannor as with internal pressure. External pressure causes the tube to buckle and that is why hard drawn tube is used as it needs to be as round as possible to resist the buckling forces.

The model boiler books by Harris and Evans both have a list for tube sizes. Kozo did not address the issue of flue tube sizes in his article on the safety of copper boilers. The AMBSC has a table for flue sizes very similar to Harris and Evans. I did notice also that the Maryland Code does not have anything on flue sizes.

When you showed your calcs on the 1/3 Case how was the flue tube issue handled?

Dan

 

[steamin]

Dan, I poured over the thread covering 'Flue Tube Calculations" late last night. I copied the formulas and transferred them to a word document that is on my laptop desk top right now. I hope to run some numbers in the next day or two. I understand with what is being said about external pressure vs. internal pressure. It has also been my understanding that a seamless round tube is stronger under external pressure (compression strength) than internal pressure (tensile strength) due to the geometry involved. I suppose if I had looked a little deeper in the Boiler Thread I could have seen my original questions had already been answered. Sorry for going down the same trail again. I do appreciate your patience ! Hopefully I can present some pictures of the fabrication of the boiler fairly soon. There are some items I want to finish with the frame while it is still all assembled. Then I plan to do a complete disassembly and then work on the boiler.

Dan, what I presented to the NC Board of Labor was based on the formulas that I gleaned from the Maryland Board of Labor. Yes, there was nothing about flue tubes and the NC boiler inspector never questioned the size or wall thickness that I used in my 1/3 scale CASE. He was more concerned about the materials used. I was able to hand him copies of the specs of the materials I used in the boiler. The inspector looked over the calculations, gave a visual inspection and we fired the engine and ran it up so he could see that the pressure gauge correlated with the setting of the safety valve . The inspector gave me a tag with a number on it after the test. Later I received a bill and upon payment received paper work designating my boiler a "Special Boiler".

 

[Dan Rowe]

Larry, no worries about bringing this up again.

The other thread was was interesting but it really did not cover what is needed to show a State boiler Inspector in the United States. I do not think a reference to a thread on HMEM will do. I was startled when I realized that Kozo did not cover this in his article. I have to admit that I had not even noticed that fact until this was brought up and that is a bit embarrassing.

I did a search of the MacMaster & Carr hard copper tube and compared it to the AMBSC Part 1 Copper Boilers Table 3.10.1. Some of the copper tube I can buy does not meet AMBSC specs. Now I know that the AMBSC is not a legal code in the US but it has standard model practice which is a good place to start if nothing else can be found.

I think the place to look for code rules in the United States is the ASME code. Kozo referenced some places to start looking in that code and it is on my list to get down to the U. of TX to read the ASME code to see what it says about copper for boiler flue tubes.

You mentioned the specs that you showed the inspector. What did they include was the tube type L copper pipe?
You also mentioned the specs for the steel for this boiler did that information come from the Maryland boiler code?

Thanks for helping explain what it takes to get a State Special boiler cert.

Dan

 

[steamin]

HI Dan, The Maryland document gave me the formulas for calculating the working pressure, ultimate bursting pressure, stay bolt size and pitch. I did not pursue what Maryland spec out for materials. I just went to my local boiler fabricator and purchased the necessary plate materials. I purchased the steel flue tubes from Kilsby-Roberts Tube Sales. In both cases they provided the material certifications that I could share with whomever to show that I used PVG (Pressure Vessel Quality) materials throughout the boiler.

North Carolina does not have any "Model Boiler Codes" in place. They have been very gracious to work with those of us who wish to go the inspection route. A few of us modelers were trying to start the procedure for establishing model codes in NC, but it met a lot of opposition from the vast majority of model steam participants. They had no kind words for inspectors and an inspection process, so the movement has died.

I have mounted my boiler tag in a prominent place for all to see when we are belted up to the sawmill. It has helped the show sponsors to realize that I have jumped through some hoops to make the 1/3 scale CASE as safe as possible. worst case scenario is that I have to do a hydrostatic test or fire the engine and pop off the safety valve to prove that it works at its set pressure.

The only place I have been denied to run my CASE was at the Rough and Tumble show in Kinser, PA. They said I was welcome, but leave my CASE at home.

The LaFrance boiler is my first experience using copper for flue tubes and especially doing the rolling process. But with your words of wisdom and supportive information from others, I feel that the method I have shared with all of you will be a success.

I have ordered my copper flue tubes from Coles Power Models. I do not know the specs of the copper. I assume and we know what that could mean, that it is of the proper grade for miniature boiler fabrication.

Again thank you for your interest and support.

 

[GWRdriver]

A few of us modelers were trying to start the procedure for establishing model codes in NC, but it met a lot of opposition from the vast majority of model steam participants. They had no kind words for inspectors and an inspection process, so the movement has died.

All known attempts to create a US Model Code in the last 50 years, and there have been a number, have been squashed by two attitudes. Those would be the "Ain't nobody going to tell me what I can or can't do with my train" folks, who always quote something about "freedom" or "rights" or some such, and then there are the "A Model Code is great, as long as the person dictating what's in it is ME." folks. Then some of the objections are about dollars, people don't want to have to do things right because doing it right might cost them more money or be more trouble. I understand that, but one boiler done on the cheap or carelessly, resulting in one injury, is all it would take to bring unwanted Gubmint scrutiny down on our heads. I've been shouted down in more than one forum for speaking in favor of a US national model code - it's a very touchy subject. One thing some model code objectors don't seem to be willing to accept is gaining legal standing under a state code by an exclusion. This can protect live steamers far more than we are hurt by it. There are number of states where operating an amateur built miniature boiler was once illlegal, a felony, and might still be if it hadn't been for the foresight and work of live steamers in gaining an exclusions in their state boiler codes. But there is a tradeoff for legal standing which is that we must abide by the terms of the exclusions, which can vary widely from state to state, but in retrospect exclusions seem to me to be a more workable solution than herding cats (ie, creating a national model code.)

I do think the percentage of boiler builders, or potential boiler builders, who want to do it right is on the rise as people recognize the benefits to all of us of making things as safe as possible and go on to lead by example, as Steamin is. As a curious addendum to the boiler safety issue, based upon several occurrences in the last ten years or so, and in the experience of my own club with our insurers, the insurance companies aren't particularly concerned with little boilers. Their #1 concern these days is loss and liability due to personal (passenger/rider) injury, public or private, and that's where the most changes in safety precautions and operating procedure have come from in the last five years or so. We haven't done enough as clubs, apparently, to police ourselves (so we can be free to do what we want, etc), and common sense doesn't apply in liability cases, so the insurance companies have stepped in and are issuing ultimatums, either do what we say to help us insure you, or there will be no insurance. So if the insurors aren't concerned about boilers why should we? The reason insurers aren't concerned is that so far we've given them no reason (no losses) to be concerned. I hope we can continue giving them no reasons to be. We occasionally see mentioned here the AMBSC (Australian) code and then there's the Federation Regs in the UK, but I believe I am right in saying that neither of these model Codes were the result of Gubmint intrusion or instigation. These were driven by insurance issues first and then subsequent development was done in cooperation with Gubmint agencies.

 

[steamin]

Yes, we scale steam modelers face a lot adversities with the different rules, regulations and the lack of the same from state to state concerning boiler design, fabrication and the materials to be used. This is why I support forums such as this; it helps and/or provides information that will help others to build a safe working boiler and steam equipment.

Since I do not see anything such as a national scale model boiler code on the horizon, I encourage anyone who is around steam operated models and even the full size counterparts to question anything that they feel is out of place or being operated in an unsafe manner. We need to step up to the plate and take charge of our surroundings. I have done it several times and the owners were not aware of the situation at hand and appreciated my input. I am sure there will be a time that I will be told to go fly a kite, but at least I will have done my part to help keep the hobby a little more safer.

GWRdriver, I understand exactly what you are saying and there was a long discussion about this very topic on the SmokStak forum. Maybe if you start a thread devoted to this topic it may reach more individuals and provide the fuel needed to start a movement for a "National Model Boiler Code".

What I was trying to say in my last posting was; the NC Board of Labor was willing to work with me. As I showed them kindness and respect, it was returned with their services to help me to be a better informed steam engineer and boiler fabricator.

 

[Dan Rowe]

Larry a karma point for the extra effort to keep the hobby safe and building a State Special.

I do not think there is much hope for a National Model Boiler Code but with out reasonable dialogue on the subject there will never be any reason to hope for such a code. I started a thread on US State Boiler Code and located the online link for most of the state boiler codes. http://www.homemodelenginemachinist.com/index.php?topic=8846.0 That might be a good place to start the discussion or another separate thread if that seams the best.

I have been thinking about the flue tubes for the boiler this thread it about. It might be a good idea to give space for a future retube with 3/8" tubes. It was not easy to source 5/16" tubes in the US and that most likely will not change. The roller could be modified for the 3/8" tube you found by only turning down the first 1/4" or so of the cage. There is no reason to stick the roller in any further than that.

Dan

 

[steamer]

Hi Dan et al,

I agree with the concept of a code. It may be more palatable if it were based, where possible on the section 1 code, or the existing model boiler code. JMO.

Let me explain.

If we could distilled into say, re-enforcement curves, such as found in the section 1, it may be easier to convince....No I'm not volunteering... ;D

I'm just talking out loud.....Thoughts?

Dave

 

[JorgensenSteam]

I have not heard of anyone getting hurt from a tube collapsing.
It seems like when the end of a boiler fails is when the problems get big.

My problem is a boiler without an inspection hatch.
How do you look at the bottom plate and figure out the level of corrosion.

Endoscope maybe through one of the fittings?

Seems like a water tube boiler would have an advantage in the ability to inspect it, but I don't see many water tube types used.

Edit:
The other problem I see is that there are no standard boiler designs.
It seems like they could approve a couple of standardized horizontal and vertical sizes, an then you could build to an approved standard design, and would only have to worry about assembly, not the design itself or the material, since all that would be approved and tested.

 

[Maryak]

BoS

Ultrasound is your friend here, especially if you can borrow one with a graphic trace and memory. That way you can provide your inspector and yourself with the evidence as to thickness and suitability for continued service.

I say borrow because we are talking megabucks here; definitely not for a one off unless your Rupert Murdoch.

NATA registered metallurgy laboratories are a place to start combined with huge amounts of grovelling and show and tell.

Hope this helps

Best Regards
Bob

Edit......... Another option is Xray

 

[steamin]

Sir Dan, that has a "Knightly" ring to it, thank you very much for the comment.

That is a great idea about the 3/8" OD tubes. I will stick to the original flue tube hole pattern on the drawings. I was looking at the drawing the other day. I don't think I could have added any more tubes anyway. As it is, I am eliminating 2 tubes. The exhaust pipe from the cylinders ran over the top of them. I do not like the idea of flue tubes blasting the exhaust pipe with hot hot gases and/or flames.

 

[steamin]

I have been monitoring several postings in this section. The wealth of information is tremendous. Thank you to all for sharing. In a newly started thread, a gentlemen was requesting some modern day boiler wrap type insulation for his recently acquired Stuart Boiler. It has the dreaded asbestos on it and he wants to replace it. Someone suggested Blackgates or Reeves2000 for possible boiler wrap material. I checked out both web sites and did not see anything offered.

So, my fellow miniature boiler gurus, where do you and what is it that you wrap your boilers with to insulate them before you put an outside cover on it ? I will need something in the near future for my LaFrance boiler.