How big is the leak

[maltaron]

I have a pressurised system which runs at 1 bar. It has started dropping to near zero in a one to two week period. How big a leak am I looking for, a weep or a drip?

 

[Jackrae]

Lots of assumptions, but some fun maths ;

Say the capacity of your expansion vessel is 5 litres and you are losing this volume over the 2 week period

5 litres lost over 2 weeks or 14 days or 20,160 minutes.

So we are losing 5/20,160 = 0.000248 litres/minute

Say a drip weighs approx 0.05grammes and 1 litre weighs 1000grammes (1kg)
then we have 1000/.05 = 20,000 drips per litre

So the loss rate in drips per minute is the number of drips in a litre times the number of litres lost per minute = 20,000 x 0.000248 drips per minute = 5 drips per minute

So you are looking for a leak that should be observable.

 

[doitall]

Run a finger around the radiator valves and fittings, you'll probably find it

 

[leakydave]

Check that the PRV isnt letting by. Fix a plastic bag over the discharge pipe