TM 1-1500-204-23-2
Table 4-3. Hose Clamp Tightening, Fingertight-Plus Turns Method, Beaded Tubing
Clamps, radial
Initial Installation
Clamp, worm screw-type
and other type
only
(10 threads per inch)
(28 threads per Inch)
Self-Sealing Hose
Fingertight Plus 2
Fingertight Plus 2 1/2
Complete Turns
Complete Turns
Approximately 25 to 30
Inch-Pounds
All Other Aircraft Hose
Fingertight Plus 1 1/2
Fingertight Plus 2
Approximately 25 to 30
Complete Turns
Complete Turns
Inch-Pounds
Figure 4-17. MS Fitting and Components
(2) Clamps on self-sealing hose. 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 installation, and main-
tained at this torque value. When sealing is not
effective at 30 inch-pounds, component parts of con-
nection 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 clamps as well as destroy hose and
connection.
(3) Clamps on nonself-sealing hose. Hose
clamps installed on nonself-sealing hose shall be in-
stalled 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 30 inch-
pounds, component parts of connection shall be ex-
amined and unserviceable parts replaced.
4-3. Fittings. Hydraulic fittings are used
throughout the hydraulic system to provide simple
connections between hydraulic components and
tubing. Standard MS (flareless) and AN (flared) fittings
are used in Army aircraft. Both types are made in many
different shapes and designs. They may be ordered in
either male or female design or in a combination design
(male on one end and female on the other). The
hydraulic repairer is concerned with installing both the
AN and MS fittings in aircraft hydraulic systems. Nor-
mally, the fittings to be used in an aircraft hydraulic
system are selected according to the design of the
system. The hydraulic repairer repairs fitting failures by
duplicating the original installation.
4-14
