2"Scale Clayton Undertype

Hi Everybody and a Happy New Yea

Can I pick somebodys brains on boiler construction

I am working on a boiler for a 2"scale Clayton undertype.

The end plates are flanged and a bit of a swine to work on as the outer ring of holes are quite close to the edge of the flange.

Now this is where I will probably get shot down in flames.

Is there anything wrong with making the end plates of the boiler out of thick copper plate say 3/16"" with stainless steel stays threaded into the plate.

I know this is all theory has anybody ever done it os is it too week of a construction method.

Cheers

Neil

PS has anybody got a safety valve for one of these boilers

If you can do the calculations and show your boiler inspector that 3/16" plate will work you may be OK but will have to go for bronze stays not stainless.

Whatever you do speak to whoever will certify the boiler before deviating from the original design.

Should be able to make the safety valve

I think that with stainless stays in a copper boiler, with hot water you could just about use the current to light the engines head lamp, in other words you may have an electrolytic problem. As Jason says, go with bronze.

Ian S C

Under our Australian code for model boilers the rules state that stainless steel should not be used for integral pressure parts of a boiler. (this rule does not apply for superheaters, valve spindles, etc)

As stated already you should check with whoever is going to inspect your boiler that its construction complies with a design code for safe operation otherwise you could waste a lot of time and money.

Paul.

I may be misreading your post but are you suggesting doing away with the flanges. without them I cant see how you could make an effective seal and all the points the previous posters have made would wekaen it even further. Question - are you trying to flange after drilling the holes possibly? I would reccomend flanging with lots of annealing then draw out the tube positions and the tube outside diameters accurately on a sheet of heavyweight paper. Then stick this inside the flanged end of the plate. This way you can confirm that the tubes will not foul the flange . centre through the marking ( I use a tiny bit in an archimedes hand drill ) and drill out the tube positions from these. I have done a few tube plates like this in the past where the tubes are close to the flange with a good success rate.

Kind regards

BK.

The original question concerned the proximity of the tube holes to the flange. I had no bother in that respect with my Clayton boiler (I built it in 1988 or so and I wish I'd made it an inch taller!) Provided you drill the holes AFTER you flange the ends, you should have no trouble.

I made my safety valves a bit larger than the drawings, as I'd heard that they were on the limit regarding the accumulation test.