The life of a mechanical seal depends on various factors such as cleanliness of the liquid handled and its
lubricating properties. Due to the diversity 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 mechanical seal fails.
5.7.2 Packed stuffing box
WARNING:
Lock out driver power to prevent accidental start-up and physical injury.
The stuffing box is not packed at the factory and must be packed properly before operation of the pump.
The packing is furnished in a box of fittings which accompany the pump. The packing used must be suit-
able for the pumpage. Make sure the stuffing box is clean. Examine shaft-sleeve for wear or scoring, re-
place if necessary.
Starting from the innermost ring, the packing is usually arranged as two packing rings, lantern ring, three
packing rings, followed by the split gland. Insert single packing rings by twisting as shown in
. Press each ring to ensure proper compression in the stuffing box. Stagger joints 90°.
Lightly and evenly tighten the gland. Excessive tightening will result in premature failure of the packing
and shaft sleeve. After packing, it must be possible to rotate shaft by hand. Final adjustment of packing
gland is made after pump is started.
5.8 Impeller clearance setting
WARNING:
Lock out driver power to prevent accidental startup and physical injury.
A change in pump performance may be noted over time by a drop in head or flow or an increase in pow-
er required. Performance can usually be renewed by adjusting the impeller clearance.
5.9 Feeler gauge method (all but CV)
1.
If shims are already installed, loosen motor lock bolts (3708) and remove shims.
2.
Loosen the jacking bolts (370D) and back out about four turns.
3.
Begin tightening the motor lock bolts (3708) evenly, drawing the motor (338) towards the pump until
the impeller contacts the casing. Turn shaft to ensure contact is made.
4.
Use a feeler gauge to measure the gap between the motor face and the frame adapter (Fig. 26).
5.8 Impeller clearance setting
34
3196CC Installation, Operation and Maintenance Instructions
