pressure testing

[Peter_R]

what would be the hydrostatic testing pressure on a G3 boiler, I get to 75psi befor the relief valves blow.
do I need to gag the reliefs to go higher ?

[Andy B]

Hello Peter,

Normal procedure for boiler testing is to have a set of blanking plugs - for all the bushes for the safety valves, water gauge, pressure gauge, etc., except one bush which has a fitting to connect to the test pump.
These are used when doing the hydraulic test to 1.5x or 2 x working pressure (sorry, I don't have the required figure to hand, but no doubt someone will soon post to correct me).

The model pressure gauge is also tested against a master calibrated gauge whilst off the loco.

Once that is done, the fittings are all put back for the steam test - during which the safety valve opening pressure is checked.

Hope this helps,

Andy

[Peter_R]

Thanks Andy,
I left the relieve valves it to check the trip pressure. Maybe they need replacing too. I don't know what the running pressure is for G3 models, so any help please.
Peter

[AllWight]

I believe the normal working pressure is under 80lbs for g3 models. The person to talk to is Dick Allan.
I drive a lot larger engines on a 7 1/4 guage line near Ringwood and we operate boiler pressures on a range from 100-150lbs on the various engines.

Mark

[MikeWilliams]

The best person to speak to is Alan Marsden.  He is the G3S authorised boiler tester, so what he says goes.

Mike

[Peter_R]

Ok!, where and how would I get hold of Dick or Allan

[MikeWilliams]

Assuming you are not a member of the Gauge 3 Society and thus don't have access to a membership list, drop a note to any of the committee whose details are on their web site.  I'm sure they will put you in touch one way or another.

.... and I would recommend you join the Society - its inexpensive and greatly motivating.

Mike