I didn’t meddle with it. Most things at Cane Hill were dangerous enough without the need for tinkering with pressurized gas cylinders.

"The gas cylinder you refer to in your Cane Hill project is actually an oxygen cylinder (in the UK all oxygen cylinders are black with a white collar). It looks from the gauge to be just over a quarter full. The attachment on the cylinder itself where the green tubing is emerging from is the flow meter - from 1 litre of oxygen per minute up to 15 (this is where the regulation of oxygen takes place)." - Jason