A welding apparatus having a specially designed receptacle that is formed on the rear molded plastic panel that is affixed to an enclosure in assembling the welding apparatus. A gas valve having a hexagonal body fits snugly into a mating hexagonal shaped of the receptacle. A pair of fingers extend outwardly from the rear panel and have distal ends with barbs formed thereon. In the assembly of the welding apparatus, therefore, the gas valve is simply inserted into the complementary shaped receptacle formed in the rear panel and the barbs snap over the external surface of the gas valve to retain the gas in the desired position affixed to the rear panel while automatically aligning a gas inlet port of the gas valve with an opening in the rear panel to allow accessibility of the gas inlet to an external source of gas.