ASME B16.9 is the dimensional and pressure-temperature rating standard for factory-made wrought butt-welding fittings including elbow, tee, reducer, cap, and cross. This guide covers material specifications, welding considerations, and Wuxi ABK equipment (HBJ positioner, HGZ rotator, ZHGK fit-up, TTW orbital) for pressure vessel nozzle, process piping, and pipeline spool fabrication.