HU U-Shaped Radiant Tube – Ø152.4 × Ø142.8 × 2154.24 mm Custom High-Temperature Radiant Tube Assembly for Industrial Furnaces | FH® Alloy FH® Alloy manufactures HU U-shaped radiant tubes for industrial furnaces and heat treatment equipment, providing custom solutions according to furnace drawings, operating temperature, atmosphere, burner configuration, and installation requirements. This U-shaped radiant tube is manufactured from HU heat-resistant alloy with a tube size of