Thanks Geoff.
At this point we are trying to determine what "fail" actually means. What value of leak is permitted.
I have been told that the demand valves have to comply with BS4272-2 when produced. I can't find the details of the standard anywhere unfortunately (without paying for it!) - so if anybody can help there I would appreciate it.
I am led to believe there is a internal and an external leak tolerance. The internal being the demand valve itself and the external being the hose. I think the figures mentioned were something along the lines of 0.5mL/min
Connecting to a 4 bar supply with a mass flow meter in series seems the logical way to test for any leaks to me, i'm just wondering if anybody actually does this kind of test and over what time.
With the greener NHS programme in full swing we are looking at cutting down our nitrous and Entonox usage hence why we are looking at the demand valves.
