Filling question

[danf1234]

Another noob question regarding home bottle filling. I have been watching a lot of you tubes, and I am right in thinking that the fill valves on HPA regulators are one way.

so once the pressure is drained from the line at the compressor bleed screw it is safe to disconnect the line. There is also no danger of bleed back if a half full tank is connected to be topped up?

 

[Tommikka]

Another noob question regarding home bottle filling. I have been watching a lot of you tubes, and I am right in thinking that the fill valves on HPA regulators are one way.

so once the pressure is drained from the line at the compressor bleed screw it is safe to disconnect the line. There is also no danger of bleed back if a half full tank is connected to be topped up?

Correct

Regulator fill nipples have an internal valve which will not open until the fill station pressure exceeds the bottle pressure 

A compressor or dive cylinder based fill station will exceed your cylinders pressure and open the valve.  A stirrup pump fill will need some pumps to get started

Note that there will be a small amount of air lost when purging the fill line after filling, but the cylinder will not bleed back when connected