3-65.
What is the first step in
replacing an O-ring in a
disassembled fluid power system
component?
1.
Identify the rings size and
material
2.
Inspect the ring for cuts,
nicks, and flaws
3.
Install felt washers on both
sides of the ring
4.
Lubricate the O-ring groove
and all surfaces over which
the ring must slide
3-66.
What is/are used when the O-ring
installation requires spanning or
inserting through sharp threaded
areas, ridges, slots, and edges?
1.
O-ring expanders
2.
O-ring entering sleeves
3.
A rolling motion of the
O-ring
4.
A light coating of the
threads with MIL-S-8802
3-67.
What device is used to prevent
3-68.
3-69.
3-70.
O-ring seal extrusion under
pressure?
1.
Backup ring
2.
Cup packing
3.
Flange packing
4.
Gasket
Backup rings made from which of
the following materials are the
most widely used?
1.
Cork
2.
Leather
3.
Tetrafluorethylene (TFE)
4.
Bakelite
What is the age of deterioration
of TFE backup rings?
1.
1 year
2.
3 years
3.
5 years
4.
TFE does not deteriorate
When the packing in a fluid power
system component is being
replaced, the backup washers
should be inspected for which of
the following conditions?
1.
Fray
2.
cuts
3.
Evidence of compression
damage
4.
All of the above
3-71.
Which of the following statements
about a Quad-Ring is false?
1.
It can be used at extremely
high pressures
2.
It provides a seal in only
one direction
3.
It eliminates the spiral
twist sometimes encountered
with O-rings
4.
It can be used as a static
seal as well as a packing for
reciprocating or rotary
motion
3-72.
Which of the following statements
is incorrect concerning U-cups
and U-packings?
1.
They are usually made of
different materials
2.
They both seal on the OD and
the ID
3.
They are interchangeable
4.
They have cross sections
resembling the letter U
3-73.
What type of seal is least
desirable and is used only where
there is not sufficient space for
a U-ring packing or a V-ring
packing?
1.
Cup
2.
Flange
3.
O-ring
4.
Quad-Ring
3-74.
How are O-rings stored?
1.
They are hung from pegs
2.
They are kept under tension
3.
They are kept in their
original envelopes
4.
They are kept in a light,
moist atmosphere with a
strong draft
3-75.
A torn O-ring package is properly
secured with which of the
following materials?
1.
Staples
2.
Moistureproof glue
3.
Outer covering of
moistureproof paper
4.
Pressure-sensitive,
moistureproof tape
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