TUBES AND COMPRESSION FITTINGS

TM 5-3805-254-34 1-19. ANTISEIZING TAPE (Con’t). CAUTION Do not exceed specified torque or use power tools to tighten fittings taped with antiseizing tape. Overtightening could damage fitting threads and cause connection to leak. (4) Using hand tools, tighten fittings to specified torque. 1-20. TUBES AND COMPRESSION FITTINGS. a. Tubes with inverted nuts and compression fittings are designed for one-time assembly. Once assembled, they must be replaced as a unit if any parts are found defective. Used parts may not seal properly when used with new ones. b. Used tube assemblies in good condition can be installed to their original location without leaking. c. Assemble new tubes, compression sleeves, and inverted nuts as follows: (1) Slide inverted nut onto end of tube. (2) Slide compression sleeve onto end of tube. (3) Repeat steps (1) and (2) for other end of tube as required. d. Install new tube assemblies as follows: (1) Insert end of tube as far as it will go into fitting to which tube is being installed. (2) Screw Inverted nut into fitting and tighten it against compression sleeve with open end wrench. Compression sleeve will clamp down around tube and conform to internal surface of fitting and inverted nut. (3) Repeat steps (1) and (2) for other end of tube as required. 1-21. LOCKWIRE. a. Always use nonelectrical wire (Item 34, Appendix B). b. Drilled head screws and bolts usually do not require lockwiring if they are installed with self-locking nuts or lockwashers. c. Three screws or bolts are the maximum number that may be lockwired in a series when they are spaced 4-6 In. (10.16-15.24 cm) apart. The maximum number of closely-spaced multiple groups of screws or bolts to be lockwired, is limited to the number of units that can be lockwired with a 24 in. (60.96 cm) length of wire. d. Do not secure screws, bolts, or fittings which are spaced more than 6 in. (15.24 cm) apart. Lockwire these fasteners to tiepoints 6 in. (15.24 cm) or less away. e. Lockwire parts so that tension will be on lockwire when parts tend to loosen. Lockwire should be installed and twisted tightly so that loop around head stays down and does not come up over head of screw or bolt. This does not apply to castellated nuts when slot is close to top of nuts; wire is more secure when made to pass along the side of stud. Ensure that lockwire is tight but not overstressed. f. Make pigtail of Y-X in. (6.35-12.70 mm) at end of lockwire. Bend pigtail down so it will not become a snag. g. When lockwiring castellated nuts, tighten nut to low side of torque range, then continue tightening until slot lines up with hole. 1-9