Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

As thick as that is and the way it’s secured, I don’t think it’s going to give you any troubles...

Its bedded down on the Mamod silicone water seal. There's only the size of that keyhole opening that you can see in the brass retainer through to the boiler.

Ran it for two hours now with a few top ups with the safety valve blowing off. I think that's a pretty good pressure test.