Figure 4-1. Printed - Symbol identification Tape.

TM 1-1500-204-23-2 Figure 4-1. Printed - Symbol identification Tape. d. Cutting Tubing, To ensure a good flared tubing connection, tubing should be cut squarely, and the end deburred before it is flared (see figure 4-3). The standard tubing cutter is clamped over tubing and rotated toward its open side as cutting wheel is gradually fed into tube by turning thumbscrew. The cutting wheel should be fed into the tube only while the cutter is being rotated, as dents will be caused in tubing if the cutter is note moving. Moderate or light tension on thumbscrew will prevent bending and excessive burrs on tubing. If a cutter is not available, a hacksaw blade with 32 teeth per inch can be used. Figure 4-2. Solid Color Band Identification. burnishing with hand tools. Nicked tubing is not only weaker as to internal pressure, but such nicks must be burnished out to reduce a notch effect. If nicks are not burnished out, concentration under vibration will cause weakening and breaking at nicked point. Burnishing re- moves notches by removal of surrounding material. Bur- nishing is not allowed in the heel of bends where material has already been stretched thin during forming. Where tubing is used for fluid’s (liquid or gaseous) at atmospher- ic pressure or less, bursting strength of tubing is unimpor- tant and, therefore, dents and nicks may be disregarded providing that the tubing is structurally sound for its spe- cific application, internally unobstructed, and that is re- mains leaktight at all times. Dents can be removed from tubing by drawing a bullet through tubing. The diameter of the bullet must be equal to or slightly less than the inside diameter of the tubing. Figure 4-3. Cutting Tube with Tube Cutter. e. Bending Tubing. Tubing may be bent with any one of a variety of bending tools. The hand bending tool is shown in figure 4-4. Bending in a smaller radius than limits shown in table 4-1, or forming flattened, kinked, or wrinkled bends should be avoided (see figure 4-5). MIL-T-7081-6061T-6 aluminum tubing may be formed through tubing processes by maintaining a 1-inch bend radius for 1/4-inch and 3/8-inch tubing. All sizes above 3/8 inch will require the use of a mandrel to form. Bends in 5/16 inch outside diameter oxygen tubing should 4-2 Change 1