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Boiler Testing

bruce morgans

Joined: 21-01-05

Topics: 6

Replies: 18

Posted: Wed 20th Mar 2013, 5:07pm
Boiler Testing

10.4.b refers to a 'recommended' range of water temperatures when carrying out an hydraulic test on a boiler. Can anyone enlighten me as to why a test should not be carried out at say 6 degrees. Would I be correct in saying the important issue here is not the actual water temperature but the need to prevent the boiler from 'sweating'. This of course can occur at anytime when the metal temperature is below the ambient temperature such that the air reaches its 'dew point'. If 'sweating' occurs the test would need to be ended. I am surprised that nowhere in the Green Book does it refer to this phenomenon and what to do if it occurs.
I do acknowledge the reference to keeping the water temperature as close to the ambient temperature as possible, which would of course prevent 'sweating'.

Replies To This Post


Joined: 19-09-01

Topics: 0

Replies: 8

Posted: Thu 21st Mar 2013, 12:53am

From memory it was put in as the properties of the metals are significantly different below 6 degrees.
There was also concern about people filling up a boiler using a hose pipe but in the workshop. The water may be at 4 degrees but the workshop at 20 so as soon as the blanking plugs are put in and if the pump valve happens to be shut the pressure would be rising as the water warms up and expands.
I forget the exact figures but a few degrees rise in temperature can make a big change in pressure, hence best to use water at ambient temperature.
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