Not sure, to be honest. I can lift the 95 litre tank in my Range Rover with one hand, so probably about 20-30kg? When it's full there's about 40kg of gas in,

Not sure, to be honest. I can lift the 95 litre tank in my Range Rover with one hand, so probably about 20-30kg? When it's full there's about 40kg of gas in, so that's very much a two-man lift. But bear in mind that's something like 6mm steel and intended to be literally indestructible. The dinky fibreglass gas bottles you get for patio heaters and forklifts are about 5kg and take an 11kg fill, which isn't a lot. 10 bar is not much more than the pressure in your car tyre, and roughly same as the average road bike tyre (currently running about 12 in my road bike). If you disconnect a 10 bar compressed air line, it hisses a bit. If you disconnect a 10 bar LPG line you get a lot of very cold gas on your hand, and it'll take ages to get the mercaptan-y smell off you.