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
