Manual

NOTICE:
• The mechanical seal must have an appropriate seal flush system or excess heat generation and seal
failure can occur.
Reference drawing
The manufacturer supplies a reference drawing with the data package. Keep this drawing for future use
when you perform maintenance and seal adjustments. The seal drawing specifies the required flush fluid
and attachment points.
Before you start the pump
Check the seal and all flush piping.
Mechanical seal life
The life of a mechanical seal depends on the cleanliness of the pumped fluid. Due to the diversity of
operating conditions, it is not possible to give definite indications as to the life of a mechanical seal.
Packed stuffing-box maintenance
WARNING:
• Never attempt to replace the packing until the driver is properly locked out and the coupling spacer is
removed.
Accepted leakage rate
It is not necessary to shut down or disassemble the pump to inspect the packing operation. During normal
operation, the packing should leak approximately one drop per minute.
Adjustment of gland
Adjust the gland if the leakage rate is greater than or less than the specified rate.
Evenly adjust each of the two gland bolts with a one-quarter (1/4) turn until the desired leakage rate is
obtained. Tighten the bolts to decrease the rate. Loosen the bolts to increase the rate.
Tightening of packing
NOTICE: Never over-tighten packing to the point where less than one drop per minute is observed.
Over-tightening can cause excessive wear and power consumption during operation.
If you cannot tighten the packing to obtain less than the specified leakage rate, then replace the packing.
Dynamic seal maintenance (3180 and 3185 S, M, L, and XL groups only)
Precautions
WARNING:
• Packed stuffing boxes are not allowed in an ATEX-classified environment.
• Dynamic seals are not allowed in an ATEX-classified environment.
Dynamic seal parts
Dynamic seal parts normally do not wear enough to affect operation unless the service is particularly
abrasive. The dynamic seal consists of two parts:
• The repeller seal prevents leakage during operation.
• The secondary seal prevents or minimizes leakage during shutdown of the unit. The seal can be either
one of these types:
• Graphite packing, which provides adequate life when it runs dry but can provide longer
performance if it is lubricated with clean water or grease.
• Diaphragm seal, which is an elastomeric disk that seals against a follower when the pump is not
operating.
Maintenance
66 Models 3180, 3181, 3185, and 3186 Installation, Operation, and Maintenance Manual