This specification covers heat-treated wrought carbon steel piping fittings with lowered carbon content of seamless and electric fusion-welded construction for low-temperature and corrosive service applications. These fittings are for use in pressure components where inherent notch toughness and optimum sulfide-cracking resistance are required, such as oil and gas industry piping and distribution systems. The materials shall be manufactured by forging and shaping methods which involves hammering, pressing, piercing, extruding, upsetting, rolling, bending, fusion welding, machining, or by a combination of these operations. Fittings shall be heat treated by normalizing, quenching, and tempering or stress-relieving. Product analyses shall be performed wherein specimens shall conform to required chemical composition of carbon, manganese, phosphorus, sulfur, silicon, nickel, chromium, molybdenum, and copper. The fittings shall undergo tension and impact tests, and shall conform to the following mechanical requirements: yield strength, tensile strength, elongation, and notch toughness.
