... : Nut, Male Sub, Female Sub, Seal Ring; Sour Service Models to NACE MR-01-75. Recommended service ... : Nut, Male Sub, Female Sub, Seal Ring; Sour Service Models to NACE MR-01-75. Recommended service ... : Nut, Male Sub, Female Sub, Seal Ring; Sour Service Models to NACE MR-01-75. Recommended service ... : Nut, Male Sub, Female Sub, Seal Ring; Sour Service Models to NACE MR-01-75. Recommended service ...