Goulds Pumps XHD - IOM - Manual (Page 69)

Maintenance
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 second is
observed. Over-tightening can cause excessive wear and power consumption during opera-
tion.
If you cannot tighten the packing to obtain less than the specified leakage rate, then replace the
packing.
Dynamic seal maintenance
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 expeller 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.
Expeller seal maintenance
Some services might require a flush if solids have built up on the expeller. The unit contains a
flush tap for that purpose. The unit also contains a drain tap in order to drain the expeller
chamber if there is a danger that the unit might freeze.
Graphite packing maintenance
Graphite packing requires the same maintenance as any other packing. When adjustments can
no longer be made with the gland because it contacts the box face, perform these maintenance
tasks:
• Shut down the pump.
• Relieve the pressure.
• Add another ring of packing to the box.
If the lantern ring connection is used but no longer lines up with the flush port, you need to
clean and repack the stuffing box. The repacking procedure is the same as the procedure
outlined in the Commissioning, Startup, Operation, and Shutdown chapter except this is the
arrangement:
• One ring of packing
• The lantern ring
• Two rings of packing
Acceptable leaks
Slight leaks can be considered normal, but excessive dripping or spray indicates a problem.
XHD Installation, Operation, and Maintenance Manual 67