Bell OH-58A - Page 158

TM 55-1520-228-BD
HYDRAULIC
Ratchet the cutter around the tubing
applying a light pressure to the cutting
wheel by intermittently twisting the
setscrew. Too much pressure on the
cutting wheel could deform the tubing or
cause excessive burring. After cutting
the tubing, carefully remove any burrs
from inside and outside of the tube. If
a tube cutter is not available or if
tubing of hard material is to be cut,
use a fine toothed hacksaw, preferably
one having 32 teeth per inch. After
sawing, file the end of the tube square
and smooth and remove all burrs. Be
sure all filings and cuttings are
removed from the tubing.
Inspect the
tubing end to verify its roundness, its
being cut square, and that it is clean
and free from marks and scratches.
Figure 9-6 illustrates properly burred
tubing.
NOTE
After tubing has been cut, all
efforts should be made to flush
any residue from the tube end.
Flush with any available fluid
or if end connections are inacces-
sible, momentary activation of
the system will suffice.
9-7. ALUMINUM TUBING DAMAGE.
GENERAL INFORMATION: Aluminum tubing is
subject to damage by projectiles and
fragments.
Replacement with original
replacement parts is desirable, but not
essential. In BDAR, tubing and hose, AN
and MS fittings, and other similar com-
ponents can be substituted one for the
other. Available time, tools, skills,
and materials will determine which
repair option to use.
Whenever an alu-
minum line has complex bends, replace-
ment of the damaged section with
hose, option 3, is probably the
quickest fix.
OPTION 1:
In Line Repair.
LIMITATIONS: None.
PERSONNEL/TIME REQUIRED:
● 1 Soldier
● 30 Minutes
MATERIALS/TOOLS REQUIRED:
● 2 MS Unions
● Splice Tube
● Tubing Cutter
● Knife or File
● 4 MS Fittings
PROCEDURAL STEPS:
1. Cut and remove damaged section of
tubing, Figure 9-7. Tube ends must be
square.
2. Clean ends of undamaged tubing with
knife or file.
3. Measure the distance between the two
undamaged ends and prepare a tube splice
replacement section of this size.
Clean
ends of splice section as done in step 2.
4. Install an MS fitting on each end
of the splice tube, Figure 9-8.
5. Insert the splice tube and tighten
all fittings, Figure 9-9.
6. Record BDAR action taken. When
mission is complete, as soon as
practical, repair the equipment/system
using standard maintenance procedures.
9-6