LGP cylinder & production line, including: shell stretching machine, edge cutting machine, offsetting machine, punching machine, rust removing machine, necking welder, leakage testing machine, welder of handle and skirt of cylinder, circular welder, assembly bottle machine, conveyor roller type, painting line, valve tightening machine, stamping machine, anneal furnace, hydraulic pressure testing machine, sandblast machine, zinc spraying machine, print machine etc.