Boiler testing

[Mike BrettParticipant @mikebrett89695]

Hi all

I have built a small collection of stationary steam engines that I run on compressed air. However, I thought it would be nice to occasionally run them on steam. To this purpose I have purchased a five and a half inch guage locomotive boiler. Most of my engines will run on as little as two to four pounds of air and a few need eight to ten pounds. I intend to fit two 15psi mamod type safety valves to the boiler. My question is, with such low pressure, would I need a test certificate or indeed, would they even test a boiler at such a low pressure. I have the facilities to hydraulic test, but what should this test pressure be – two or three times working pressure?

The boiler is very well constructed and very heavy, far superior to any mamod/wilsco boiler, so I do not envisage any problems. Advice please.

[Mike BrettParticipant @mikebrett89695]

Low pressure boiler use.

[JasonBModerator @jasonb]

One thing to watch if using two Mamod safety valves is that you have a far bigger heating area so the boiler will be capable of producing far more steam than a couple of little Mamods and the small valves will probably not be capable of venting it all which could lead to an increase in poressure within the boiler even if both valves are blowing off.

The steam test requires the valves to allow no more than 10% over working pressure with a heathy fire under it.

Your boiler would most likely still fall within the testing range as the capacity in litres x working pressure in bar would be over the minimum of 3

[Mike BrettParticipant @mikebrett89695]

Good point Jason, I will fit two larger safety valves then. Not sure what heating to use yet, certainly not coal, might use gas so could turn of instantly.

[Neil WyattModerator @neilwyatt]

Posted by Mike Brett on 28/11/2016 21:10:59:

Good point Jason, I will fit two larger safety valves then. Not sure what heating to use yet, certainly not coal, might use gas so could turn of instantly.

The point of the safety valves is they protect you the day you go to put the kettle one and the phone rings and the postman knocks (twice) and you forgot about the boiler for thirty minutes…

[Author]

Posts