I wish we'd team build a boiler now

[Brass_Machine]

Everyone has valid points here. I see both sides of this.

I understand what Bob is saying about this hobby being inherently dangerous. I think the key here is that when you are in your shop... you and you alone are responsible for the safe operation and maintenance of your machines. It is not anyone's fault if you leave a key in your chuck but your own.

When you add in the aspect of other people building parts for a boiler, then you are relying on someone else. While yes, more than likely everyone here can build the accessories for a boiler with no problems (bungs etc...) that is the possibility of a problem. Even the tiny boilers can be a bomb. Why take the chance?

I don't think anyone here is viewing a boiler as wildly more dangerous, it's the introduction of unknown variables to the boiler building process. We all know boilers are and can be dangerous, why add to that?

If people want to get together and build parts for a boiler, more power to you. It may work out just fine. I won't however be involved nor will I officially endorse a team build for it.

I foresee this thread taking a turn for the worse. We have all been civil up to this point. Remember, we are all friends here and lets keep it civil to prevent locking of this thread and worse yet, bad feelings among members.

Eric

 

[firebird]

Hi

Well Iv'e just read all the posts about 3 times now. Very interesting. I imagine most of you have been following my boiler making project. Firstly I read as much as I could on the subject until I was happy that I could attempt a simple boiler. I particularly studied the safety side of things as I quickly became aware of the possible dangers involved. I stated right at the start of my post that it should be considered experimental and not a set of plans to follow. Before I started I figured out a way to hydraulic test it and intend to get it re-checked by a club inspector with the view of running at shows. I have recieved a lot of help and advice along the way and my thanks go to all that have joined in, John and Sandy C to name just two. I want to make a small boiler. What I do in my own workshop I consider is down to me and the risk is all mine but I make every attempt to stay on the right side of safety. If I'm not sure about something I will ask and heed the advice given. There is a vast amount of knowledge here on this forum and I take on board all I can get. I have to say though, even with my limited knowledge, that I'm not sure about a TEAM BUILD. Doing everything myself I have full control over the build so can only blame myself if anything goes wrong. Having said that I doubt that one man at the professional boiler builders makes all the parts and then solders them together himself. I think for us model makers doing it all yourself would be the best option. Just my opinion for what its worth.

Cheers

Rich.

P.S.

I haven't posted anything for a while re A SMALL BOILER because I haven't been in the shop for a while. I hope to get on with something next week.

 

[Divided He ad]

I'm not trying to stir things up again.... I just remembered seeing this and thought it very poignant to this thread.


[ame]http://www.youtube.com/watch?v=0R348vGkjyw[/ame]


If you watched this to the violent end and took note of what the inexperienced builder and friends were saying then you will now know that some people do very stupid things with SAFTY/PRESSURE RELEASE valves!!!

I'm not saying that anyone here would tighten the pressure release to the point that it may as well just be a bolt! But it does certainly happen.

I for one will take great care in future when I do decide to make/run boilers. (and yes I will make one or more at some point.)


Ralph.

 

[Brass_Machine]

Point proven. That video shows even the small "hobby" boilers can be dangerous. I hope no-one was hurt with all the flying metal.

Granted that boiler looked like hell and they were heating it with a torch... but still.


Eric

 

[Mcgyver]

Poor old Darwin, food supply chains of the western world have arrested natural selection (if you need proof watch the Jerry Springer show) and now you guys want to reduce the chances of the feeble minded blowing themselves up? how’s the species to evolve? ;D

Firstly I read as much as I could on the subject until I was happy that I could attempt a simple boiler.

that imo was the best thing written in this thread. When one sets out to build a boiler, from knowing nothing, it necessitates a lot of reading and investigation ....whether this research is targeted at safety or not matters not...the proponent picks it up through the process. In other words to go from being clueless to being ready to build generally involves enough self education that the inquisitive gets the finer points of safely designing and construction (unless they're a Darwin award candidate, and that’s beyond our ability to stop).

There persist though a lot of misunderstanding about the dangers and where they come from. John, the danger isn't the 2500 lbs, that’s simply a force (ie a boiler under steam has magnitudes more potential energy than a boiler under hydrostatic test yet both have at 2500 lbs force)....the force becomes lethal if there is enough energy to maintain the force for some length of time/distance.... In the case of a boiler there’s a lot of potential energy stored as heat in the water and ready to instantly release on a sudden pressure drop.

As far as I'm concerned, its all good if it makes people more aware of the issues and dangers.....unlike most things we make where the risks are operational within our four walls (leaving the chuck key in), a boiler is not an operational risk, its potentially a risky product to leave our shop and can involve innocent bystanders are exposed if we are negligent. A small boiler at 125 psi letting go isn't like getting burned by some steam, its a small stick of dynamite. Very different from leaving the chuck key in, imo

 

[BobWarfield]

Here is a fascinating paper for the very safety-minded audience we have here:

http://lib.hpu.edu.cn/comp_meeting/PROGRESS IN SAFETY SCIENCE AND TECHNOLOGY VOL.V1/1369.doc

Nice little model to estimate relative explosive power of your boiler if things go south. I set up a spreadsheet to do the calculations they offer and plugged in parameters similar to my desired boiler:

4" diameter by 10" long
It blows when it is 7/8 full of water (the saturated water being much more dangerous than the steam on top)
188 psi (well above anything I'd remotely want to run at--assumes the relief valve is not working and we heated the little sucker way too hot until it blew

This model says that's 1/4 stick of dynamite right there. An M80 from my childhood, 1/4 lb of TNT, or not quite half a pound of gunpowder. If you leave the pressure and the relative water to steam ratio the same, the model scales well with volume.

Just thought you'd like to know!

Best,

BW

 

[Circlip]

I'm surprised Sandy hasn't made a comment on this one John B? Oh dear, this one is a case of wishes and capabilities.
A few years ago on this side of the pond, many of the "Depot" type stores were doing a bouncing trade supplying the "Do it yerself" dummies. "What is your hobby?" Do it meself. Fortunately (Although some still try it on) legislation was passed so that a certificate is required (even by people that had been doing it for a living) to prove to the owners/insurance companies that the person who had installed a gas appliance was qualified to do so and followed ALL the regulations. Up until that time any idiot could do this whether they were capable or not and boy oh boy have I seen some c4ap and I'm not CORGI registered (Qualification). A few years later, the sparks (Electricians) got jealous and got the same sort of thing passed for electrical installations. Luckily I installed ALL my own services before this became the law. Why? Cos I'm not a qualified gas fitter or sparks but would put my work up for inspection by the relevent authorities without fear of rejection. (Had to do this when I laid some drains to connect to main system,and was complimented by the inspector who had a quick look at all the other services I'd put in and was dumbfounded that I "Wasn't in the trade"
OK, boilers, make yer own? why not. Make bits for someone else? Are you prepared to get TEST CERT'S for ALL the metals you're going to use? No, you're not allowed "Look what I found at my local scrap dealer" Cos in the event of a BANG, someone from the insurance company is going to ask for them. How many people do we trust to help us make a potential bomb? And before you jump in Ranger, SHHHHH and chill. We're not trying to nanny you, just trying to ensure you reach your 15th birthday and many more with ALL your bits intact. Full size boiler makers (There are still one or two left over here) don't make all their own fittings etc but there is TOTAL traceability of parts. Would I make my own? YES, but I would make sure that it was PROPERLY tested and certified before eventhinking about warming it up.
Play safely, Regards Ian.

 

[Bogstandard]

Sandy is having personal issues at the moment, so I would suggest no one tries contact. He will be back when ready.

John

 

[chuck foster]

bogs, if you happen to chat to sandy give him our best.

chuck

 

[BobWarfield]

Fellas, FWIW, I am tending towards the water in tube designs. This puts the high pressure bits inside the firebox, which seems like an extra margin of safety if it goes *BANG*.

I really like the Yarrow-style marine boilers, though it would be a lot of trouble to make one. They seem less fussy than the monotubes because they can contain a bit more water. A monotube is what ranger is building. They're dead easy. The Yarrow will take a bit of doing. I'm finding that stainless tubing is cheaper than copper, so that'll likely be the material of choice. Will need to make a tubing bender as well, so I won't start the boiler until I've got my mill CNC"d and we're done with TB2 in all likelihood.

FWIW, here is a link to a site that has a very cool Yarrow boiler for a steam launch:

http://www.steamboating.de/list/li-main.html

I'm not planning anything nearly that big! Mine will likely be a desktop size. Suppose it was something similar that fit in a firebox 6"x6"x6" or so. I may draw up some 3D models of it beforehand. It'll be a good silver soldering project for sure.

I'm thinking of a boiler similar to that Yarrow with some sort of alcohol burner arrangement like what Firebird has been fooling with and a vertical stack. I think that should work out well.

FYI, John Bentley (The Engineman) also has a Yarrow-style design on his steam tugboat. Apparently water in tube boilers were more common in Marine and stationary applications than in locomotives.

Cheers,

BW

 

[Dick L.]

Hi Bob, have you seen this Roberts design built to power one of Ray HasBrouck's engine designs? The boiler looks similar to a Yarrow.
Dick

http://plsntcov.8m.com/stmbot.htm

 

[Bernd]

I've just read the all of the posts on the boiler building subject. I have not built a boiler yet, but wish to build one in the future. I've read many books and magazine articles on the subject. Also my dad has built several boilers to run steam engines on. I am by no means an expert on the subject.

What I would like to add to this discusion is the fact that water under pressure boils at a much higher temperature than 212 degrees F. So when the boiler ruptures the pressure drops and the super heated water turns to steam instantly, thus a explosion.

I saw a TV program of people in an under water habitat that had a hole in the floor for divers to enter and exit. I could not understand how the water did not come in until they explained that the vessel was under a certain pressure ( I do not recall at what pressure they were). But what caught my attention was that they had to use a thermometer to check the temp of the water for there coffee because the water would boil at 350 degrees F. Way to hot to drink.

Somebody correct me if I'm wrong here.

Bernd

 

[Bogstandard]

You are exactly right on that assumption Bernt.

It also works the other way around, mountain climbers will boil water, but because of the reduced atmospheric pressure, it is only warm when it is boiling.

John

 

[bentprop]

I haven't had the courage to get involved in team builds,and because of my geographical location I probably never will,but I certainly would NEVER EVER use any boiler I didn't know the history of without a very thorough pressure test.
Divided's video is a timely reminder to be cautious with anything involving pressure vessels.
There is also the small matter of cost.Have you seen the price of copper sheet (or tube,for that matter)?
Even a small boiler can easily run into $300-$400 in materials.Being heavy,it will also be costly in shipping anywhere.
Sorry to rain on your parade,Bob,but I think you may have to go it alone on that one.

 

[Tin Falcon]

I saw a TV program of people in an under water habitat that had a hole in the floor for divers to enter and exit. I could not understand how the water did not come in until they explained that the vessel was under a certain pressure ( I do not recall at what pressure they were). But what caught my attention was that they had to use a thermometer to check the temp of the water for there coffee because the water would boil at 350 degrees F. Way to hot to drink.

Somebody correct me if I'm wrong here.

Bernd

The pressure inside the diving bell or habitat would be determined by the depth the divers are at. 33ft of water =14.5 psi or one atmosphere. so 99 ft of water would be three times the pressure as compared to the air at the surface.
If one looked at charts the pressure could be determined by the 350 degree boiling point.
regardless of the details point well taken.
Tin

 

[BobWarfield]

Thank you Dick L., that's quite a nice Yarrow-style boiler.

I'm going to quit posting to this thread though. It's too depressing. Should have been renamed "The exploding boiler train wreck thread." ;D

Cheers,

BW

 

[tel]

Don't give up on it Bob, I've built and steamed a bunch of boilers over the last 30 years & I'm still around to tell the tale. Just a matter of procedure really, same as anything else.

 

[Bogstandard]

I think you have the wrong end of the stick Bob.

No one is saying 'don't make one', the general consensus is do make one, but do everything yourself, rather than relying on someone elses build qualities.

John

 

[Circlip]

And just to rain on your parade a bit more Bob, a watertube boiler is potentially far more dangerous than a Flash steamer.
Regards Ian

 

[Divided He ad]

I have to agree with John here Bob.

I have never made a boiler, but will do so some time soon.
If I used one of my manufactured ones (Mamod/SEL) I would expect them to be reasonably safe (as long as I had kept them well serviced) But I would wonder and worry a little about the home made boiler that I had little to do with. I would worry even more about the possible consequences of a failure to a boiler that I had supplied to another party!

My posting of the video was not to say don't! It was just to say do it safely.... Not crank down the safety valve and use a blowtorch etc etc....
You can and probably have watched and read it.

I think if you look back over this thread there is a mine of very usefull information about boilers, building and their testing etc.... IMO it has been very informative and will be referred to (all the bickering removed and just the usefull facts kept) when I take up the boiler building challenge. ;D



Ralph.