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

Don't know what Ill power with them just playing with um . Made four of these .Gonna put 150 PSI tomorrow if they don't go to Mars  I thank they will be ok with a safety release at 40 PSI

150 PSI is an awful lot for an un-stayed boiler. Additionally, over-pressure can actually weaken one by distorting the copper.

As I recall, initial boiler tests run at twice the proposed working pressure. Subsequent tests (annual) use 1.5 times the working pressure.

Just my 2¢ worth....