TM 55-1520-240-23-6
7-4.2
TUBE BENDING (AVIM)
(Continued)
7-4.2
16.
Check bends in tube (1) with micrometer as
follows:
a.
Measure and record maximum outside
diameter (OD).
b.
Measure and record minimum OD.
NOTE
Operations of steps c, d, and e can be
expressed as follows:
(
)
c.
Subtract OD of step 16b from OD of step 16a.
d.
Divide result found in step 16c by average
(nominal) OD of tube (1).
e.
Multiply result found in step 16d by 100.
f.
Result found in step 16e is percent of ovality.
17.
Acceptable level of tube ovality or flatness shall
be 5 percent maximum.
Solvent (E161) is combustible and
toxic. It can irritate skin and cause
burns. Use only with adequate
ventilation, away from open flame. In
case of contact, immediately flush
skin or eyes with water for at least
15 minutes. Get medical attention
for eyes.
18.
Clean tube (1). Use solvent (E161).
Propelled debris can cause injury to
eyes. Use source of compressed air
under 30 psi and eye protection to
prevent injury to personnel.
19.
Dry tube (1) with low pressure compressed air.
Wear goggles to protect eyes.
20.
Inspect tube (1). There shall be no wrinkles
or kinks deeper than 1 percent of nominal
OD. There shall be no scratches deeper than
5 percent.
FOLLOW-ON MAINTENANCE:
Install end fittings and sleeves as required (Task 7-5).
Apply appropriate identification markings (APP E-50).
END OF TASK
7-26
