Figure 4-16. Installed Low-Pressure Hose

TM 1-1500-204-23-2 any appreciable torque to fitting Maximum wrench tor- ques, in inch-pounds, for fitting nuts on various sizes and types of tubing are shown In table 4-2. j. Installation of Beaded Tubing. Beaded tubing Is used In low-pressure applications using rubber hose and hose clamps (see figure 4-16). (1) Proper sealing of hose connections. 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 hose clamps as per (2) or (3) below, Figure 4-16. Installed Low-Pressure Hose depending on the hose type. In the absence of a hose clamp torque wrench, the fingertight-plus-turns method shown in table 4-3 should be used. Due to the variance in hose clamp design and hose structure, values given in table 4-3 are approximate and care should be exer- cised when tightening clamps by this method. NOTE Aircraft hose constructed with synthetic com- pound has 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 Table 4-2. Hydraulic Tubing B-Nut (AN818) Torque Values Torque on tube nut Tube outside Aluminum alloy Steel tubing diameter tubing 1/4 Inch 40-65 Inch-Pounds 135-150 Inch-Pounds 5/16 Inch 60-80 Inch-Pounds 180-200 Inch-Pounds 3/8 Inch 75-125 Inch-Pounds 270-300 Inch-Pounds 1/2 Inch 150-250 Inch-Pounds 450-500 Inch-Pounds 5/8 Inch 200-350 Inch-Pounds 650-700 Inch-Pounds 3/4 Inch 300-500 Inch-Pounds 900-1,000 Inch-Pounds 1 Inch 500-700 Inch-Pounds 1,200-1,400 Inch-Pounds 4-13