[modeleng] Re: Boiler Certificates

The first thing is a careful visual examination of the boiler.
This will usually require removal of the insulation & cladding.

Then, plug up all the outlets apart from two.
Into one fit the Test Guage. This should be a certified gauge, not the 
little one fitted to the boiler.
In the other, the pump.
Fill with water, and by that I mean that it must be completely full, with no 
air spaces.

Then pump us to test pressure. For the first test this is 2 x working 
pressure, for subsequent ttests, 1.5 x WP.
Sit and 'ave a cuppa, whilst watching for drips, leaks, jets of water, or 
anything else that makes you want to tear your hair out.!
If the pressure stays up, for at least 20 minutes (I believe the rules say 
10 mins), then release some water, and uncouple the pump.

Reconnect all the fittings that you uncoupled and blanked off for the 
hydraulic test.
Check that there are two methods of feeding water into the boiler. (Might be 
a good idea to see if pumps work at this point.)
Light a fire, and build it up as usual, watching the test pressure guage 
whilst so doing.

At the working pressure, the safety valves should blow. If they do, they can 
then be locked at that setting, if not, adjust so that they do.
Check the models pressure guage to see how accurate it is and what the 
reading is when at WP.
(The model guage should be, or will need to be, marked with a red line at 
WP.)

Check that injectors, if fitted, work.

Then continue buildin the fire, and using the blower to see if you can 
manage to beat the safety valves and get the pressure to rise above WP.
You should not be able to.
The basis must be that no matter what you do, it is impossible to get the 
pressure to rise over the WP.

(A lot of earlier designs fail at this point due to restricted outlets of 
the safety valves.)

Assuming that it passes this OK, then that is it.

Now, if you are taking your loco to a club to be tested, find out what 
fittings their pump and guage has, beforehand, and make adaptors to fit your 
engine.
(My experience is that clubs stocks of adaptors evaporate, so the chance 
that the one you need will be there, is slim!)




Alan Stepney

http://www.alanstepney.info
Model Engineering & steam engine information pages
----- Original Message ----- 
From: "kenny.macdougall" <kenny.macdougall@xxxxxxxxxxxxxx>
To: <modeleng@xxxxxxxxxxxxx>
Sent: Saturday, August 25, 2007 8:04 AM
Subject: [modeleng] Boiler Certificates


Hi Alan
What is invoved in testing a boiler on a 5 inch gauge loco /made of kent
kenny

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