Fizzy,

There was a long descusion about just this in 'Ours' many many moons ago, if memory serves, but do not remember if there was any definitive outcome.

One of the theories/arguments for not having the regulator before the SH elements, was that when closing said regulator, steam already in the system would continue to expand and heat up and the loco would not stop as required.

Anyway, with our locos, the volume of steam is too small to have any effect, and in any case, the full size ones had no such theoretical problem.

All my locos have/had the regulator before the superheater.

As you mentioned, a boiler would empty itself PDQ, and in quite a spectacular fashion.

Saw this happen at the JLS Club one Sunday when a safety valve was tapped to stop it leaking. It cried enough, parted company with the boiler and took off skywards. Made everyone jump at the sound and sight of all that pent up energy being suddenly released.

A spectacular sight it was.

Oh, it was a brass safety valve to boot, never to be found, it having been eaten away at the boiler bush, hence brass being a taboo for such fittings.

Geoff – Still coughing

hi nigel,

due to the very basic boiler, and very basic valve gear etc on Invicta, i dont think there is much point fitting superheaters. it is not as if you are going to be able to run the loco with long travel valves and long lap and expansive working.

i am otherwise a strong adherent of superheaters on miniature locos.

the regulator position on your design is a further very strong reason not to fit superheaters.

the return bends on stainless elements should not be silver soldered anyway and ought to be TIG welded

cheers,

julian