Quote Originally Posted by angrybear View Post
Er not quite,

Firstly you need to close & seal the circuit, that can be with a blanking plug, or by fitting the rifle to the end of the hose.

Now when you open the cylinder valve the gauge on the cyl will show the back pressure in the hose, up to the pressure that is in the cyl,

if that pressure exceeds the pressure in the rifle it will force open the rifle fill valve and you will hear the air flow in to the rifle.

As the rifle fill valve opens you should see the cyl gauge flick down to whatever the rifle contains & while filling the cyl gauge reads for the whole system including rifle.

When you close the cyl valve the gauge reads what is in both the hose & the rifle, and should hold that pressure until you vent it,

then you open the vent to drain the hose so that it can be disconnected & the cyl gauge drops to zero.

Obviously, you cannot fill the rifle with more pressure than the cyl contains & at every rifle fill the cyl pressure will drop until it to needs a refill.

Also you keep saying 'regulator', when it probably isn't one, which is pretty confusing.
a regulator is a device to control the amount of pressure that comes out of a cylinder it will have two gauges one for the cyl pressure & one to set the outlet pressure.

The cyl has a 'Valve' to open & close which on a surface cyl has a gauge & bleed valve built in to it,
or on a scuba tank without a gauge, you should have an Airgun Adaptor which has a gauge, bleed valve & the hose which fit to the cyl outlet.
My bad angrybear. So the dive cylinder valve with guage is just a valve. Sorry i though wrong. Ok so i need tp keep the pressure going to force open the gun valve? The gun is empty so the valve should be open due to no pressure in the gun? Never had to fill a completely empty gun before so that why i was concerned not seeing pressure when i closed the dive tank valve. Just a bit twitchy as i mentioned earlier i have not had to fill a empty gun before so made me a bit nervous seeing no pressure reading when valve in tank was closed. Thanks very much for all the comments. Bloody springers are so much easier