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5-4 MAINTENANCE OF SHAFT SEALS
5-4.1 Mechanical Seals
When mechanical seals are installed, a manufacturer’s reference drawing is supplied with the data package. This drawing
should be kept for future use when performing maintenance and adjusting the seal. The seal drawing will also specify
required flush liquid and attachment points. The seal and all flush piping must be checked and installed as needed prior to
starting the pump.
Note: The life of a mechanical seal depends on various factors such as cleanliness of liquid handled and its lubricating
properties. Due to the variety of operating conditions it is, however, not possible to give definite indications as to its life.
WARNING
Never operate the pump without liquid supplied to
mechanical seal. Running a mechanical seal dry, even for a
few seconds, can cause seal damage and must be avoided.
Physical injury can occur if the mechanical seal fails.
5-4.2 Packed Back Cover
WARNING
Shut down driver power to prevent accidental start up and
physical injury.
1.
The back cover plate is not packed at the factory and must be packed properly before operation of pump. The
packing is furnished in a box of fittings that accompany the pump. The packing used must be suitable for the
pumpage. Make sure the back cover plate is clean. Examine shaft-sleeve for wear or scoring, replace if necessary.
Starting from the innermost ring, the packing is usually arranged as two packing rings, lantern ring, and three
packing rings, followed by the split gland. Insert single packing rings by twisting. Press each ring to ensure proper
compression in the back cover plate. Stagger joints 90
.
2.
Lightly and evenly tighten the gland. Excessive tightening will result in premature failure of the packing and shaft-
sleeve. After packing is installed it must be possible to rotate the shaft by hand. Final adjustment of packing gland
is made after pump is started.