Maintenance
Model 3410 Installation, Operation, and Maintenance Manual
56
If other types of couplings are used, then follow the maintenance instructions provided by the
coupling manufacturer.
Shaft-seal maintenance
Packed stuffing box maintenance
Check or instruction
Explanation/comment
When starting a pump with fiber packing
for the first time, make sure that the
packing is slightly loose without causing
an air leak. As the pump runs in, gradual-
ly tighten the gland bolts evenly.
Never draw the gland to the point where the packing is
compressed too tightly and no leakage occurs. This will burn
the packing, score the shaft sleeve, and prevent circulation of
the liquid that cools the packing.
Turn the rotating element by hand.
The stuffing box is improperly packed or adjusted if friction in
the box prevents turning the rotating element by hand. A
properly operated stuffing box runs lukewarm with a slow drip
of sealing liquid.
After the pump has been in operation for
some time and the packing is completely
run in, check that the stuffing box leaks at
the rate of 40–60 drops per minute.
This indicates proper packing, shaft sleeve lubrication, and
cooling.
NOTICE:
Eccentricity of the shaft or sleeve through the packing can
result in excess leakage. Make sure that the parts are properly
centered.
Check the packing frequently and replace
as service indicates.
Six months is a reasonable expected life, depending on
operating conditions. Use a packing tool in order to remove all
old packing from the stuffing box. Never reuse old packing or
add new rings to old packing. Clean the stuffing box thorough-
ly before you install new packing.
Check the condition of the shaft or sleeve
for possible scoring or eccentricity and
make replacements as necessary.
—
When placing new, non-asbestos pack-
ing into the stuffing box, open the molded
rings sideways and push the joints into
the stuffing box first. Then install the rings
one at a time, making sure to seat each
ring firmly. Stagger the joints at a 90°
rotation from each preceding joint.
—
Mechanical seal maintenance
Keep in mind the following general rules regarding mechanical seal maintenance. Refer to the
instructions provided by the seal manufacturer for detailed information.
• Mechanical seals are precision products that must be treated with care. Use special care
when handling seals. Make sure that oil and parts are clean in order to prevent scratching
the finely lapped sealing faces. Even light scratches on these faces can result in leaky
seals.
• Mechanical seals typically require no adjustment or maintenance except for routine
replacement of worn or broken parts.
• A used mechanical seal should not be put back into service unless the sealing faces have
been replaced or relapped. Relapping is practical only for seals that are 2 in. (5.1 cm) or
larger.
For optimum seal life, always follow these precautions:
• Keep the seal faces as clean as possible.
• Keep the seal as cool as possible.
• Make sure the seal always has proper lubrication.
• If the seal is lubricated with filtered fluid, then clean the filter frequently.