Gas cylinder PKL against explosion 0.5 kg thick yellow

PKL Indian gas cylinder, refillable, 0.5 kilogram, Indian manufacture, company pkl, holding the Saudi quality mark (G). What is the metal thickness of the cylinder? 1.6 mm for the 0.5 kg cylinder. What is the welding method? A mixture of copper and bronze in a continuous thermal furnace with a protective atmosphere. What is the type of safety valve in the cylinder? In case of explosion, it opens the safety release valve with automatic closure between 22-30 bar and closes when above 20 bar.