Goulds Pumps LF 3196 i-FRAME - IOM - Manual (Page 56)

The dynamic seal consists of two parts:
• Repeller seal
• Secondary seal (one of the following):
• Graphite packing
• Diaphragm seal
Table 9: Dynamic seal part function
Part Function
Repeller seal A repeller seal prevents liquid from entering the stuffing box during
operation. The repeller normally does not require a flush. However, for
services that allow a build-up of solids on the repeller, you must install a
flush connection. If a danger of freezing exists, then you must install a
drain connection to drain the repeller chamber.
Secondary seal (graphite
packing)
This secondary seal prevents leaks during pump shutdown and is
comprised of the following:
• Graphite packing – Graphite packing provides adequate life running
dry but can provide longer performance if lubricated with clean water
or grease.
• If you lubricate with clean water, then the repeller reduces both the
quantity and pressure of seal water that is necessary. If the suction head
is less than the repeller capability, then the stuffing box pressure is the
same as the atmospheric pressure. Water pressure for the seal must be
high enough to overcome static head when the pump is not operating
to keep pumped fluid out of the packing. There must be enough flow
to cool the packing.
• If you lubricate with grease, then you must use spring-loaded grease
lubricators to maintain a constant supply.
• Elastomeric face seal – The elastomeric face seal consists of an
elastomer rotary fitted to the shaft and a ceramic stationary seat fitted
in the gland. To set an elastomeric face seal, refer to Set an elastomeric
face seal. This seal is designed to run dry, so no flush is necessary.
Set an elastomeric face seal
This procedure ensures that the elastomeric seal attains proper contact. No other adjustments are
necessary.
1. Remove the gland nuts.
2. Slide the gland back on the sleeve.
3. Pull the rotary back on the sleeve until the rotary is about 1 in. (25 mm) beyond the stuffing box face.
4. Push the gland back onto the studs, pushing the rotary back along the sleeve.
5. Tighten the gland nuts.
Pump priming
Prime the pump with the suction supply above the pump
1. Slowly open the suction isolation valve.
2. Open the air vents on the suction and discharge piping until the pumped fluid flows out.
3. Close the air vents.
Commissioning, Startup, Operation, and Shutdown
54 Model LF 3196 i-FRAME Installation, Operation, and Maintenance Manual