Figure 4-28. AN Flared Fittings

TM 1-1500-204-23-2 Figure 4-28. AN Flared Fittings (5) Position repair insert NOTE When positioning hose clamps or tightening screws, care should be taken to prevent screws from chafing or damaging adjacent parts. Where such damage is possible, hose clamps should be repositioned on hose. (6) Slip hose connections midway over junction formed by original tube and repair section Use glycerine, Federal Specification O-G-491, on metal pipe to aid sliding of rubber hose. (7) Tighten hose clamps. To prevent breakage of hose clamps and damage to hose, instructions on tightening hose clamps shall be followed carefully When available, use any approved torque wrench to torque clamps as per (a) OR (b) below, depending on the hose type. In the absense of a hose clamp torque wrench, the fingertight-plus-turnsmethod shown In table 4-10 should be used. Due to the variance In hose clamp design and hose structure, values given in table 4-10 are approximate and care should be exercised when tightening clamps by this method. NOTE Aircraft hose constructed with synthetic com- pound has a tendency to cold flow, therefore, when new hose is Installed, clamps should, after a period of time, be retightened In order to maintain original torque value. This is caused by synthetic rubber flowing from under clamping area and not from loosening of clamps. (a) Hose clamps installed on self-sealing hose shall be tightened to a torque of 25 Inch-pounds minimum to 30 Inch-pounds maximum for original Instal- lation, and maintained at this torque value When seal- ing is not effective at 30 Inch-pounds, component parts of connection shall be examined, and unserviceable parts replaced Under no circumstances shall hose clamp be tightened In excess of 30 Inch-pounds In an attempt to effect sealing This added torque will reduce safety factor of hose clamp as well as destroy hose and connection. (b) Hose clamps Installed on nonself-sealing hose shall be Installed and maintained at a torque of 25 inch-pounds minimum to 30 Inch-pounds maximum. If satisfactory sealing is not accomplished at a torque of 4-27