Page 292 - The Tribology Handbook

Mechanical piston rod packings B26

3 Unequal segment ring
Description

The rings are pegged to prevent the gaps lining up. Garter
springs are fitted to ensure rod contact. The bore of the
larger segment matches the rod.
Applications

Rather more robust than tangentially cut rings (2) and
hence more suitable for carbon-graphite packings.

4 Contracting rod packing

Description
Cast iron L-ring with bronze or white metal inner ring or
three piece packing with filled PTFE and metallic back-up
ring. Contact with rod maintained by ring tension. Rings
pegged to prevent the gaps from lining up. Note: this style
of packing has to be assembled over the end of the rod.

Applications
Used for both metallic and filled PTFE packings.

5 Cone ring

Description
Three ring seal-each ring in three segments with bore,
matching rod. Cone angle ranging from 75" at pressure
end to 45" at atmosphere end.
Applications
Used for both metallic and filled PTFE packings.

B26.2