Figure 6-22.—Cushioned steel clamp MIL-C-85052.
by hand until resistance to turning develops. If it is
impossible to use fingers to run nut down, use a
wrench. Look out for the first signs of bottoming. Do
not use pliers to tighten tube connectors.
Final tightening should begin at the point where
the nut begins to bottom. Use a torque wrench if
fitting is accessible and torque fitting. If a connection
is not accessible for torque wrench, use a wrench to
turn nut one-sixth turn while holding the connector
with another wrench to prevent the connector from
turning. A one-sixth turn equals the travel of one flat
on a hex nut. Tighten nut an additional one-sixth turn
if the connector leaks. Do not tighten fitting nut more
than one-third of a turn (two flats on nuts). Loosen
and completely disconnect the nut if the leak
continues.
Inspect fitting components for scores,
cracks, foreign material, or damage from previous
overtightening.
Reassemble fitting. Fingertighten
nut and repeat wrench tightening. It is important to
tighten tube fitting nuts properly. A fitting wrench or
an open-end wrench should be used when tightening
connections.
All hydraulic tubing should be supported from
rigid structures by cushioned steel clamps
MIL-C-85052 or multiple tube block clamps. See
figure 6-22. Hydraulic tubing support clamps should
be installed and maintained in the positions described
in the MIM or applicable technical directives.
Unless otherwise specified, where tubing is
supported to structure or other rigid members, a
minimum clearance of 1/16 inch or where related
motion of adjoining components exists, a minimum
clearance of 1/4 inch is to be maintained. Table 6-10
shows the maximum allowable distance between
Table 6-10.—Maximum Distance Between Supports for Aluminum Tubing
TUBING OUTSIDE
DISTANCE BETWEEN SUPPORTS IN INCHES
DIAMETER (INCHES)
ALUMINUM ALLOY
STEEL
1/8
9-1/2
11-1/2
3/16
12
14
1/4
13-1/2
16
5/16
15
18
3/8
16-1/2
20
1/2
19
23
5/8
22
25-1/2
3/4
24
27-1/2
1
26-1/2
30-1/2
1-1/4
28-1/2
31-1/2
1-1/2
29- 1/2
32-1/2
6-22
