I'm new to the world of steam and have begun building a small vertical boiler (3" diameter) to run small simple engines that I have yet to build. I'm discovering that it's quite difficult to find clear simple information on the configuration of fittings on a boiler, so I have a few questions:
(1) I'd like the boiler to comply with regulations as far as possible, and understand that for this there will need to be two routes for getting water into the boiler. Can I just put two bushes with check valves into the barrel of the boiler side by side? Or is there some other particular configuration that is recommended (e.g. different heights, etc)?
(2) I understand that the check valves for water in should be below the working water level of the boiler. Am I right in this?
(3) I assume that the main blowdown valve should be positioned as low in the boiler as possible ( but obviously without fouling the bottom end plate). Is that correct?
Once I have the answers to these questions I can move forward on to the next stage.
Would be grateful for advice from any of you or from The Master himself if he has time!
Thanks. My boiler is now finished, and up and running:
Good luck with yours - it sounds interesting.
Good luck on your build. I fancy an electric immersion heater, and a similar sized shell. I'm about to start it's construction.
Hi Henry -
Thanks for your reply.
My original post was back in March so things have moved forward for me quite a bit since then. I had already started the boiler using copper tube etc bought from a model engineering supplier so it's the proper gear. I preferred to do it that way rather than use a kit. My design is loosely based on one by Stan Bray but it's scaled up from 2" to 3".
My questions about check valves etc have now been answered elsewhere, and I have made provision for two. I'm currently at the pressure testing stage and having fixed one small leak it's now looking good.
On firing methods, others too have warned me off coal, but others again think it's doable. Having lived with woodburning stoves for years, I have an idea for a firebox design that I think will work, so I plan to give it a go. There will be a steam blower built into the boiler which should help. The fact that it will be a bit trickier than some other methods doesn't worry me. If it really doesn't work it will be easy enough to convert the whole thing to e.g. gas. No harm in trying it out I reckon...
Regarding engines, I have the Tubal Cain books (1 and 2) that you recommend. He is fantastic but aesthetically his style isn't what I'm after. I plan to start with one or two basic oscillators of simple design (e.g. Stan Braye, Steve's Workshop, etc.) and work my way up to more sophisticated engines as my skills develop. Alongside this I have made some initial inroads into metal casting and hope to incorporate this into making some funky and unusual-looking engines.
All in good time, of course :-)
Thanks for your interest.
All the best,
rules and regulations concerning toy and model steam vary considerably from country to country especially if you intend to run your creations at a public display though most agree that what you choose to do in the privacy of your own home is pretty much up to you.
If you are just starting out you may like to obtain a boiler kit where all the calculations concerning safety and suitability of materials and construction have been done for you. This greatly increases your chances of success in your project. I have no hesitation in recommending the P M Research #1 boiler kit.
A check or clack valve is only required if you need to replenish the water in the boiler while it is running. Two independent methods of doing this are recommended for coal fired boilers. If you are a beginner a coal fired boiler really is not the best way to start. There are plenty of other ways of "putting a fire under the boiler" that are much easier to do (e.g. meths, Esbit, gel, and gas), and a lot easier to control.
I would strongly urge you to obtain "Building Simple Model Steam Engines" by Tubal Cain. By building the engines and boilers described in the book you will develop the skills necessary to tackle more challenging projects - plus they are jolly good fun!