3 1/2 Britannia working pressure

[westlin]

Can some one advise id the working pressure for the 3 1/2 Britannia is 80 psi. Cant see it on any of the drawings and just about to get my boiler tested

Thanks

Stephen

[dhamblin]

Hi Stephen, my Grandad's notes has his engine operating at 80 psi. Strangely I've yet to find this mentioned in LBSC's build notes.

Regards,

Dan

[Deleted]

I can't help with Britania but LBSC's Heilan Lassie which is very close in size is set at 80 psi

[westlin]

I spoke to Helen at Western Steam yesterday and she has said 90 psi. Ive hydraulic tested to 180psi and it still holding together, which is good. Official test on Sunday.

Thanks

[JonL]

My understanding is 80 PSI, however I can't remember where I got that from!

[Tony K]

May 3, 2019 13:10:24 GMT westlin said:

.....Ive hydraulic tested to 180psi and it still holding together, which is good. Official test on Sunday. Thanks

Let's face it - the hydraulic test would probably have been OK at 300, or perhaps even 400, but I think this kind of reasoning is flawed.
The question is - what was the boiler designed for? I have read several LBSC construction notes/articles and the boiler design pressure is never mentioned. Perhaps he made a general comment somewhere I have not seen?

The design pressure can be calculated, or at least whether it is suitable for 90psi can.
Strictly speaking, I think this should be done and the result implemented.

That said, I think most people seem to assume all LBSC designs, as defined by him, are 80psi. No doubt others have built similar, but different, boilers for up to 100psi. Overall, I would hope 80psi is accepted and do the calcs if you want more. Just my thoughts.