BOILER FOR MODEL STEAM ENGINES
Now that the model triple expansion engine is working on steam, I feel able to put it aside, again, and move onto the next project. The triple is not quite finished. It needs cylinder lagging, control rods for the cylinder drain cocks, drain tubes for the cylinder drains, and an extra pump for the condenser cooling, and some paint, possibly.
It also needs a boiler. I would like to exhibit the triple at club demonstrations and public exhibitions, but for that I need a boiler which is certified by our boiler safety authority. So I intend to make a boiler to AMBSC code, and big enough for the triple or any other engines which I might make in the foreseeable future.
This is what I have in mind….
The certification process here in Australia requires the following steps:
- Preliminary discussion with the boiler inspector (done)
- Submission of 2 sets of plans to the boiler inspector. If acceptable, one set is signed off and stamped and returned. The other set is held by the inspector.
- Inspection of the prepared components by the inspector prior to soldering/brazing/welding.
- Inspection of the firebox and tube assembly after soldering/brazing/welding.
- Inspection of the barrel and outer wrapper after soldering/brazing/welding.
- Testing the boiler after completion. This involves a hydrostatic test, at double working pressure for 20 minutes, then a steam test at 10% above working pressure.
If it passes, the boiler is certified for 12 months, after which it must be retested. If it passes the retest it is certified for 3 years.
The certification process is performed by volunteer inspectors attached to model engineering clubs, and is done at no cost.
However the materials for a boiler like this are quite costly. I managed to obtain some copper tube for the wrapper, and bought some copper plate for the firebox and boiler ends on Ebay. Bronze for the bushes from a local bearing supplier (LG2), and firetube copper tube from local plumbing supplies. All up, so far, is approaching $AUD1000. And yet to be factored is the safety valve, various cocks, sight gauge, hand pump silver solder. And I intend to make and fit a steam driven feeder pump, and possibly a steam injector.
If there is any interest in this project I will post progress notes and photos. Let me know.
I would be very interested in your progress on making this boiler.
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Thanks for the feedback Roy.
Keep soldiering on John (almost a pun there).
I for one will be most interested in your progress.
Information on sourcing materials, design and building methods will all be of much interest to me.
You may even consider an article or series for AME.
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Tim, I enjoyed that almost pun!
Will consider an article if the project turns out OK. John
I find all your posts Very interesting John, Im building a 4-6-0 loco, I just got a Lathe at auction A Myford 254 plus Already fitted with DRO S , such an Improvement on the ML7 Cheers Bn
Thanks Bernie, I get a buzz from writing and posting and really appreciate the feedback. John
Hi John, very intersting, still on my bucket list somewhere, what are you going to fire it up with?
Propane, but with possibility of coal. That’s the reason for the largish fire door. John
Not sure if this is still work in progress but I’m really interested in any available plans as Im just getting into steam and need some plans for a boiler and condenser
The vertical boiler is completed, and detailed in later posts. The plans can be obtained from ME SUPPLIES. I modified them to use 6″ pipe rather than the 5″ in the plans. Here is the link…. http://mesupplies.com.au/product/drawings-boiler