The 90-degree square duct is an accessory used for changing the direction of the supply air duct and the return pipe, in addition, it also works to take in fresh outdoor air and release dust in the air polluted in factory factories.
Stud welding uses a type of flux called Ceramic Ferrule. A ceramic ring which concentrates the heat generated, prevents oxidation and retains the molten metal in the weld zone. The Ceramic Ferrule is broken off of the fastener after the weld is completed
