Quote by Ally
How do they fill them at the depot?
I've seen it done at a filling station in NZ where it has to be done locally because otherwise transport costs would make gas too expensive to use. It is done in a well vented shed and the filling apparatus is connected to a set of weighing scales.
The operator sets the weight to be filled and the tare weight of the cylinder from the collar around the neck of the cylinder and the apparatus automatically fills the cylinder to the right weight.
There was also a chart on the wall which stated which types of cylinder could and couldn't be filled at that station.
I have pictures somewhere, I'll try and find them.
It certainly wasn't just a case of hooking the pump up via an adaptor and crossing your fingers.