That'd work, but I expect the fins would hold bubbles so might make a leak hard to spot? Why not use a long hose, if you hold it vertical for about 2-3 meters you'll get good pressure?
My mrs suggested connecting them up to the mains via the hose pipe - I'm not sure what the pressure is on the water main around here so I'm a little worried about doing that. I could try your suggestion though...
Each foot gives you about 1/2 PSI, say 3 psi per metre, mains water is about 3 or 4 bar (45 - 60psi) I'm not sure about the DRZ but most vehicles rad relief valve is only a few PSI. I'd be carefull with mains pressure!
3ft 3" in a meter so the head would be 1.5psi per meter if a foot is 0.5psi rad cap blow off is about 15-20psi (but the GG may be about 3psi) so the rad should be good up to 30psi.
Stick it on the hot tap if you have a proper boiler(not a combi) in the house.
I live in bungalow and the hot water is also at mains pressure.
That's why I was thinking of using air as I can rely on the cap to blow if the pressure got to high. With mains water I'm not sure the cap could keep up with the flow and it could over pressure very quickly.
Yeah, the 'head of pressure' method with hose is a good way to check it m8! Secure it so the hose can be left over night and check the level in the hose before and after.
