Bell OH-58A Technical Manual page 166

TM 55-1520-228-BD
HYDRAULIC
b. Selection of Proper Packing or
Selection of proper packing or
Gasket.
gasket for a particular application is
of the utmost importance.
size, shape, and material composition
must be properly determined in order for
various systems to function correctly.
Packings, gaskets, or seals like fit-
tings are made to an AN, MS, or NAS
standard. While gaskets may look alike
in general construction features and may
be of the same size, they are not
necessarily interchangeable (Table 9-2).
c. The dimensional relationship
between AN6227, AN6230, and MS28775
series o-ring packings and gaskets in
the various sizes are as follows:
AN6227-B1 through B7 are equivalent
to MS28775-006 through -012.
AN6227-B8 through B14 are equivalent
to MS28775-11O through -116.
AN6227-B15 through B27 are equivalent
to MS28775-21O through -222.
AN6227-B28 through B52 are equivalent
to MS28775-325 through -349.
AN6227-B53 through B87 are equivalent
to MS28775-426 through -460.
AN6227B88 is equivalent to MS28775-425
AN6230-B1 through B25 are equivalent
to MS28775-223 through -247.
9-14
9-10. HYDRAULIC FLUID SUBSTITUTIONS.
lost and standard replacement is not
The exact
available, a substitute fluid must be
used.
fluid.
available, any available nonflammable
lubricant can be used in a BDAR action
as a last resort.
b.
mission is complete, as soon as
practical, repair the equipment/system
using standard maintenance procedures.
a. If the original specified fluid is
Check Appendix D for a compatible
If a compatible fluid is not
CAUTION
O-rings, wipers, gaskets, or other
plastic or rubber parts of the hy-
draulic system may swell or shrink,
and for that reason continued oper-
ability of the system cannot be
guaranteed.
Following such a sub-
stitution, instructions for bringing
the system back to normal should
include checking all moving parts
of the hydraulic system and all
hydraulic activated devices for
proper operation and leaks. Where
feasible, plastic and rubber parts
should be inspected for swelling,
deformation, and other damage.
Record BDAR action taken. When