Replacement
Figure 7-8 shows a typical O-ring installation.
When such an installation shows signs of internal
or external leakage, the component must be
disassembled and the seals replaced. Sometimes
components must be resealed because of the age
limitations of the seals. The O-ring should also
be replaced whenever a gland that has been in
service is disassembled and reassembled.
Often a poor O-ring installation begins when
an old seal is removed. O-ring removal involves
working with parts that have critical surface
finishes. If hardened-steel, pointed, or sharp-
edged tools are used for removal of O-rings or
backup rings, scratches, abrasions, dents, and
other deformities on critical sealing surfaces can
result in seal failure which, in turn, can result in
Figure 7-7.—Critical dimensions of an O-ring.
might scratch or mar component surfaces or
damage the O-ring. An O-ring tool kit is
available in the supply system for O-ring in-
stallation or removal. If these tools are not on
hand, special tools can be made for this purpose.
A few examples of tools used in the removal
and installation of O-rings are illustrated in
functional failure of
When removing
not use pointed or
the equipment.
or installing O-rings, do
sharp-edged tools which
Figure 7-8.–Typical O-ring instalation.
7-9
