Vertical steel boiler

[Marinus]

Hi all,

A few weeks ago I made a vertical steel boiler.
Here's the specs:
* 1 Centre flue with 5 cross tubes
* Pressure gauge, blowdown, safety valve and regulator valve
* Working pressure 40psi
* Gas fired
* 60mm steel with 2mm wall
* Silver soldered bushings and cross tubes
* Copper brazed boiler tubes



Boiler before brazing




Boiler brazed with all my homemade fittings, including the pressure gauge Notice my sloppy brazing First time working with the oxy- acetylene torch

First steam up went up to 50 psi and there was a few pinhole leaks





Pics out in the sun




Finished boiler in relation to the steam engine.

The start of the gas burner.
 

[ths]

Hi Marinus,

Good looking boiler, should do the trick. That timber lagging should provide plenty of insulation. Just wondering why you chose steel instead of copper, which small boilers are generally made of? Perhaps it was due to availability. It's not stainless, is it?

Cheers, Hugh.

[Marinus]

Hi Marinus,

Good looking boiler, should do the trick. That timber lagging should provide plenty of insulation. Just wondering why you chose steel instead of copper, which small boilers are generally made of? Perhaps it was due to availability. It's not stainless, is it?

Cheers, Hugh.

Thank you Hugh, we just had steel and I didn't find any copper tube, unless I want to buy a 5m length It costs around $200 for 62mm dia. copper tube It's just normal mild steel tube. I want to build a marine boiler using two 72mm copper pipe cuplings that costs about $2.8 or I can hear at the new hospital that thiere building if they will sell me an off- cut copper tube

[ths]

Copper will definitely be a better choice, long term. The problem with steel as I see it is determining to what extent internal corrosion has taken place, and corrode it will, but to what extent, and after how long, cannot be predicted. This is not to detract from your effort in any way, you've done a fine job. Better to go to the hospital for a bit of copper pipe than bandages.

All the best, Hugh.

[tel]

I don't want you to take this the wrong way Marinus, but I have a few concerns with your boiler. You have done, from what I can see, a good job of putting it together BUT that 2mm wall thickness is a real worry, While that might well fall within theoretical spec for 40 psi there is absolutely no allowance for wasting or corrosion and would be good for only a few steamings at best.

Also, if you do get a piece of suitable copper pipe, please make sure that it is SEAMLESS as the common plumbing type pipe is just not adequate for the job.

As far as I can discover there are no regulations covering model boilers in South Africa but readers from other places should be aware that most countries do have such regulations and they really do need to be adhered to.

Might I suggest getting hold of the Australian AMBSC boiler codes and adhering to those for any future builds. Boilers built to these specs have a generous safety allowance, I know that some folk consider that they are over cautious, but this is not the case - your safety, and the safety of other must come first.

Also, there are any number of good books on the subject - quite a few of then available for free download on the net.

Be safe, my friend, and live to play another day!

 

[Marinus]

I don't want you to take this the wrong way Marinus, but I have a few concerns with your boiler. You have done, from what I can see, a good job of putting it together BUT that 2mm wall thickness is a real worry, While that might well fall within theoretical spec for 40 psi there is absolutely no allowance for wasting or corrosion and would be good for only a few steamings at best.

Also, if you do get a piece of suitable copper pipe, please make sure that it is SEAMLESS as the common plumbing type pipe is just not adequate for the job.

As far as I can discover there are no regulations covering model boilers in South Africa but readers from other places should be aware that most countries do have such regulations and they really do need to be adhered to.

Might I suggest getting hold of the Australian AMBSC boiler codes and adhering to those for any future builds. Boilers built to these specs have a generous safety allowance, I know that some folk consider that they are over cautious, but this is not the case - your safety, and the safety of other must come first.

Also, there are any number of good books on the subject - quite a few of then available for free download on the net.

Be safe, my friend, and live to play another day!

I know that this boiler won't last long for real jobs but it wont be steamed often. It has only been steamed twice now. The live steam locos here in SA's boilers are made out of steel, but very thick steel. I made this just as a steam toy. I've seen toy steam boilers that has been made out of 30mm dia and 1mm thick wall steel tube. We have a boiler code here in SA and I have a copy of the boiler code on my computer.

[steamer]

I don't want you to take this the wrong way Marinus, but I have a few concerns with your boiler. You have done, from what I can see, a good job of putting it together BUT that 2mm wall thickness is a real worry, While that might well fall within theoretical spec for 40 psi there is absolutely no allowance for wasting or corrosion and would be good for only a few steamings at best.

Also, if you do get a piece of suitable copper pipe, please make sure that it is SEAMLESS as the common plumbing type pipe is just not adequate for the job.

As far as I can discover there are no regulations covering model boilers in South Africa but readers from other places should be aware that most countries do have such regulations and they really do need to be adhered to.

Might I suggest getting hold of the Australian AMBSC boiler codes and adhering to those for any future builds. Boilers built to these specs have a generous safety allowance, I know that some folk consider that they are over cautious, but this is not the case - your safety, and the safety of other must come first.

Also, there are any number of good books on the subject - quite a few of then available for free download on the net.

Be safe, my friend, and live to play another day!

I know that this boiler won't last long for real jobs but it wont be steamed often. It has only been steamed twice now. The live steam locos here in SA's boilers are made out of steel, but very thick steel. I made this just as a steam toy. I've seen toy steam boilers that has been made out of 30mm dia and 1mm thick wall steel tube. We have a boiler code here in SA and I have a copy of the boiler code on my computer.

Hey Marinus....we need to talk Son.

I have a love of steam and all things steam powered...clearly you do too.  I commend you for that!...it's a mode of power that is now obscure, and needs to be kept in mind.....

But, And at this point Son I want you to listen up!

We need to respect what we doing with it.  You have stated that you have a boiler code, and that you have it on your PC...a good start, but hardly sufficient to create a safe boiler.    Among the comments already pointed out by Tel, I see no gage glass, lots of grinding on the tube sheet on a piece of material that was already thin, I haven't heard anything about a Hydrostatic test....and on the first steaming you found pin hole leaks......what is wrong here?

The first thing is the material thickness....it's too thin.   There's a period at the end of that sentence.

Second of all, you need to do the engineering to assure you have enough material in the right places....the  SA boiler code should help you there.   The math is not difficult, but its important.   I am sure you want to be safe....and the people around you ASSUME you are safe...you need to be responsible enough to do this work...or don't do it at all.
In my book, a first time boiler should be a build of a known working design.   

Get a gage glass on that boiler.    You'll notice there's another period.

You Always perform a hydrostatic test on a  boiler to 1 1/2 times the working pressure before steaming it.    Again with a period!

A well constructed boiler is a  wonderful thing......a poorly built or designed one is a BOMB.

I strongly urge you to not fire that boiler again.

Respectfully,

Dave   (steamer)  Global Moderator

[Marinus]

The boiler has been tested to 120 psi and then there wasn't any leaks (it has been pickled) so when it got heat it loosend/melted the flux and then there was a leak. The leak couln't be seen by the eye and at first I thought it was a spiders web, but then it was the steam. The gauge glass isn't actually neccesary. I've seen plenty of boilers without a gauge glass that has been factory made.  When I am going to build the copper boiler I am going to make a drawing of it and then consult one of you if the design will work.

[Jo]

The gauge glass isn't actually neccesary. I've seen plenty of boilers without a gauge glass that has been factory made.  When I am going to build the copper boiler I am going to make a drawing of it and then consult one of you if the design will work.

Boilers that do not have gauge glasses have extensive safety features in case someone makes a mistake and does not keep the water level up. On all boilers you will find two safety valves and often they will also have a fusible plug that should the water level drop the steam will extinguish the fire. Your boiler however is gas fired, this presents another set of problems again  .

Never under estimate steam: water when it converts to steam increases its volume by 1600 times and the boiler has to withstand this pressure. When it fails, and sadly it will, if the metal flying off the boiler does not cause you or bystanders serious injury then the steam will.

If you want to run your engine please use a compressor. It is much safer.

Jo

[Mosey]

WOW! Good safety advise from friends.
I am about to make my first boiler, which will be the Elmers' one with a cork for safety pop-off. I am soberly reading this post.
Thanks guys and gals for your concerns.
Mosey

[Jasonb]

The thing to remember about the "toy" boilers that you may have seen (Mamod, etc) is that they are designed to run for one fill pf meths or one fuel tab and then be refilled & refueled so there is no risk of running the boiler dry.

On yours there is no way of knowing if the water level starts to drop below the level of the cross tubes and you risk melting thes eout with your gas burner.

Also your safety valve and or pressure gauge need looking at as you stated the working pressure is 40psi but the boiler is upto 50psi with no sign of the pressure valve actuating

The model steam world has a good safety record and that is because the safety regs are followed, lets keep it that way.

J

[steamer]

Hey Marinus,

Just in case your a "I'm from Missouri" kind of guy...which means your from the "Show me State"   ....and I know I was when I was young.....here's what can happen....in a modern context with a popular TV show.

<a href="https://www.youtube.com/watch?v=jbreKn4PoAc" target="_blank">http://www.youtube.com/watch?v=jbreKn4PoAc</a>


I've also seen pictures of a 15 ton steam tractor sitting 15 feet up in a tree because the boiler blew....killed 4 people...including the owner and his son.

Before

http://www.bing.com/images/search?q=Steam+Boiler+Explosions&FORM=RESTAB#view=detail&id=F78B94630FAFAFBB51D1EE87D02840F91E978AD2&selectedIndex=37
After

http://www.bing.com/images/search?q=Steam+Boiler+Explosions&FORM=RESTAB#view=detail&id=E3B2BC4A18DCF548778C9655E7A66AA2B96246DD&selectedIndex=174
Medina Blast

I hate going this route....but I'm not telling you this because I'm trying to be a jerk....I actually care quite a bit!....not only for you and your friends and family, but for the hobby also.

Marinus, part of growing up is accepting responsibility for your actions.    This is no joke.   Please be careful.

I stand by my previous statement.    Please don't fire that boiler.

Dave