A large part of its business is fabrication of large furnace vessels called inner coves, these weldments require the firm to splice several sheets of plates into one, then roll-form the spliced work piece into a cylindrical cover.
Splice welding by proved much too time consuming, and the company has relied on Kat travel carriages since 1987 to automate the long, straight splice welds.
The company recently purchased another Gullco carriage for an upgrade to the inner-cover-fabrication area of the shop.
The inner covers, of stainless-steel sheet 11 gage (0.12 inch) to 3/16 inch thick, measure 48 to 132 inches o.d., 60 to 192 inches tall. Covers contain the atmosphere in the annealing furnace.
Most are of Type 309 stainless. An alternative material, popular in Europe and gaining acceptance in the United States, is Rolled Alloys RA253MA.
An ASTM A250 stainless (11 Ni, 21 Cr, 65 Fe), it exhibits superior strength and oxidation resistance to Type 309. Gullco visited the company during an order for 96 inner covers for a major steel mill in the Detroit area.
