Goulds Pumps VIT - IOM - Manual (Page 57)

CAUTION:
• Avoid excessive vibration levels. Excessive vibration levels can damage the bearings, stuffing box or
seal chamber, and the mechanical seal, which can result in decreased performance.
• Avoid increased radial load. Failure to do so can cause stress on the shaft and bearings.
• Avoid heat build-up. Failure to do so can cause rotating parts to score or seize.
• Avoid cavitation. Failure to do so can cause damage to the internal surfaces of the pump.
Operation under freezing conditions
NOTICE:
Do not expose an idle pump to freezing conditions. Drain all liquid that is inside the pump and the cooling
coils. Failure to do so can cause liquid to freeze and damage the pump.
Mechanical seal leaks
NOTICE:
The mechanical seal used in an Ex-classified environment must be properly certified. Prior to startup,
make sure that all areas that could leak pumped fluid to the work environment are closed.
Occasional leaks
If the seal leaks slightly at start-up, allow a reasonable amount of time for the seal to adjust itself. Fluids
with good lubricating qualities normally take longer to adjust than fluids with lesser lubricating qualities.
When a seal starts out with a slight leak and the leak decreases while running, it indicates leaks across the
seal faces. Run the pump continuously in order to eliminate this issue.
Continuous leaks
When immediate leaks occur and remain constant, even during operation, it usually indicates either
secondary seal (shaft packing) damage, or seal faces that are warped or cracked. See Troubleshooting for
probable causes.
Stuffing box leaks
CAUTION:
Packed stuffing boxes are not allowed in an ATEX-classified environment.
Normal leaks
With the pump in operation, there should be some leaking at the stuffing box packing. The correct leak
rate is a rate which keeps the shaft and stuffing box cool. This rate is approximately one drop per second.
Check the temperature of the leaked fluid as well as the discharge head.
Decreased leaks
If the pump runs hot and the leaks begin to decrease, stop the pump and allow it to cool down. Loosen
the packing gland in order to allow the packing to resume leaking. After pump has cooled, restart pump
and run it for 15 minutes. Then check the leaks. If the leak exceeds two drops per second, adjust the packing.
Commissioning, Startup, Operation, and Shutdown (Continued)
Model VIT Installation, Operation, and Maintenance 55