Keighley Laboratories, UK, has enlarged the size of one of its largest pit furnaces, increasing dimensions to 3.6 ft working diameter and almost 5.9 ft max length, in the process gaining 30% in overall capacity. The inner shell or retort is made from duplex stainless steel. At the same time, it has upgraded the lifting capacity of its overhead crane to 3 metric tons. The crane services all seven pit furnaces, a salt bath, and tempering equipment.
Enlarging the No. 1 pit furnace involved fabricating a custom-made inner shell or retort made from duplex stainless steel. This considerable investment has already been offset by orders for heat treating 3.6 ft-diameter gear wheels for an offshore application, and 5.7 ft long, 1 metric ton shafts for a renewable energy project. Indeed, the company is already considering upgrading other pit furnaces and its programmable process controllers.
“This has opened up a new market for us among engineering companies and OEMs, who are looking to heat treat larger components. This involves physical issues regarding accommodating the size of these parts, then lifting them out of the furnace and into the quench tank. The operation also demands special skills for treating very large workpieces without damage or distortion,” says Divisional Commercial Director Michael Emmott.
Keighley Labs pit furnaces do carburizing, carbonitriding, hardening and tempering, stress relieving, homogenizing and carbon restoration, working at temperatures up to 980°C. It handles steel, iron, high chrome iron, cast iron, ADI (austempered ductile iron) and alloy steel materials, for aviation, marine, defense, rail, mobile plant, energy, and general engineering companies.
