Table 6-8.—Prime and Paint for Tube Assemblies CATEGORY DESCRIPTION *PRIME PAINT I Single tube with separate Prime after forming, but Tube assemblies in connectors at each end. before fabrication. categories I, II and III II Tube assemblies consisting of Prime after forming, shall be painted after fabrication and before individual tubes permanently follow by coating joints joined by nonseparable with MIL-S-8802 before installation, except for fittings such as those fabrication. assemblies in category III assembled by brazing, which have been partially welding, and swaging and primed. having separable connectors at each free end. III Single or multiple tube Prime after forming, Partially primed tube assemblies as in I and II, follow by coating joints assemblies in category III having one or more free ends with MIL-S-8802 before shall have additional which must be subsequently fabrication. primer applied as required joined permanently to another followed by coating of all tube assembly by brazing, nonsealed-nonseparable welding and swaging during joints with MIL-S-8802 installation. If primer is not compatible before application of paint. to permanent joining process, prime tubing a suitable distance away from affected end. IV Other tube assemblies not The cognizant rework facility shall specify the required described in I, II or III. protective finishes. *Tubing assemblies in categories I, II, and III in which sleeves or ferrules are used in the separable connections and sleeves or ferrules are fixed in position by deforming one or more numbers, prime up to but not beyond initial point of contact. Tubing for use with flared systems shall be primed to the end of the tube. Oxygen system tube assemblies require special to be deposited in the tube assemblies. precautions for cleaning. After fabrication, and Oxygen reacts violently with oil and may testing, clean oxygen tube assemblies in accordance cause equipment damage and injury to with MIL-STD-1359, using trichlorotrifluoroethane personnel. Oxygen (BB-0-925) or clean, (MIL-C-81302) in a spray gun or vapor degreaser. If dry, water-pumped nitrogen (BB-N-411) a vapor degreaser is not used, tube assemblies must must be used in place of water-pumped air. remain in the vapor degreaser until the temperature Only MIL-C-81302 is approved for specified in the manufacturing instructions is reached. cleaning oxygen system tubing. Tube assemblies must be blown clean and dried with a stream of clean, dry, water-pumped air. PROTECTIVE PAINT FINISH CAUTION Tube assemblies that require paint as a protective finish are described in table 6-8. Titanium or stainless Oil-pumped air is not a suitable substitute steel tubing does not require primer or paint except in for water-pumped air because it causes oil areas of dissimilar metals. Primer or paint on 6-15