Sigma technicians are knowledgeable with ASME, AWS, ANSI, NBIC, and EEMUA standards; and are qualified to provide Preheating for steel pipe, vessels, tanks, and other metal components prior to welding.

Welding Preheat is widely used in industries such as construction, oil & gas, and shipbuilding to ensure weld quality. An area around the weld joint, or the entire part, is preheated to a specified temperature before welding. Preheating the weld (area) eliminates moisture, which in turn prevents hydrogen buildup in the weld and the potential for a failure.  Minimizing the temperature gradient between the welding arc and the base material slows the weld cooling rate and lowers hydrogen content, two factors that also help eliminate weld “cracking.”

Several options can be used for welding preheat, including open flame, resistance heating, induction, and convection ovens. For open flame, operators use a fuel gas and compressed air torch to apply heat directly to the metal part.

Qualified technicians are available for call-out or long-term assignments. Sigma provides turnkey Preheating and reporting services complete with equipment, consumables, vehicles (mileage), and accommodations required to perform the Heat Treatment.