What is the boiler pressure

What is the boiler pressure

This topic has 3 replies, 3 voices, and was last updated 15 July 2024 at 09:13 by Michael Callaghan.

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14 July 2024 at 20:05 #741345
Michael Callaghan
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@michaelcallaghan68621
Hi, can anyone please let me know the correct boiler pressure for a 2 1/2 inch gauge Dyak please.
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14 July 2024 at 22:47 #741354
Nigel Graham 2
Participant
@nigelgraham2
If you can’t find a definite answer for the design, Martin Evans’ Manual of Model Steam Locomotive Construction recommends 70psi for a 2.5″ g. locomotive. Which seems high but probably necessary for hauling a full-size driver behind it.

Is this for building new, or putting an old model back into service? If the latter and the pressure-gauge is not marked (as it should be), I would take that as a maximum and carefully consider the condition of the boiler; if necessary down-rating it.

If new, the drawings should specify the w.p., surely?

If you intend public running, even if the “public” are fellow model-engineering society members, it will need testing and the boiler inspector will need know the designed (or if down-rated, new) working pressure.
15 July 2024 at 08:11 #741369
Weary
Participant
@weary
80 lbs sq in.

(Curly’s ‘standard’ pressure)

Sample Reference.

Regards,

Phil
15 July 2024 at 09:13 #741374
Michael Callaghan
Participant
@michaelcallaghan68621
Thanks chaps, I think given the age of the boiler 70 psi would be best.
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