... thread, butt-weld; Component Parts: Nut, Male Sub, Female Sub, Seal Ring; Sour Service Models to NACE MR-01-75. Recommended service ... , butt-weld; Component Parts: Nut, Male Sub, Female Sub, Seal Ring; Sour Service Models to NACE MR-01-75. Recommended service ... weld; Component Parts: Detachable Nut, Male Sub, Female Sub, Seal Ring, Retainer Segment, Retainer Ring; Sour Service Models to NACE MR-01-75.