CAUTION:
Risk of equipment damage due to dry operation. Immediately observe the pressure gauges. If
discharge pressure is not quickly attained, stop the driver immediately, reprime, and attempt to
restart the pump.
Set desired flow
If your system is equipped with a variable frequency drive (VFD) or a variable speed V-belt drive, you
may at this point want to set your speed for the desired flow.
CAUTION:
To avoid risk of equipment damage, observe the pump for vibration levels, bearing tempera-
ture, and excessive noise. If normal levels are exceeded, shut down the pump and resolve the
issue.
5.3 Operation
General considerations
Service temperature in an ATEX classified environment is limited by the table in the ATEX identifica-
tion section.
1.
Do not operate pump below hydraulic minimum flow. For hydraulic minimum flow, refer to techni-
cal manual and pump performance curve.
2.
Do not operate pump below hydraulic or thermal minimum flow. For hydraulic minimum flows re-
fer to technical manual and pump performance curves. To calculate thermal minimum flow, refer
to HI Centrifugal Pump Design and Application ANSI/HI 1.3-2000.
3.
Do not operate pump past maximum flow. For maximum flow refer to pump performance curve.
4.
To avoid risk of equipment damage, observe the pump for vibration levels, bearing temperature,
and excessive noise. If normal levels are exceeded, shut down the pump and resolve the issue.
5.
Make sure to operate the pump at or near the rated conditions. Failure to do so can result in
pump damage from cavitation or recirculation.
6.
Vary the capacity with the regulating valve in the discharge line. Never throttle the flow from the
suction side. This action can result in decreased performance, unexpected heat generation, and
equipment damage.
7.
Net positive suction head available (NPSH
A
) must always exceed NPSH required (NPSH
R
) as
shown on the published performance curve of the pump.
8.
NPSHa must always exceed NPSHr as shown on Goulds performane curves received with order.
9.
Reference Hydraulic Institute for NPSH and pipe friction values needed to evaluate suction pip-
ing.
10. Most axial flow pumps are in evaporator circulation service and since the evaporator perform-
ance and the amount of product depends on the rate of liquid circulation, care should be taken to
maintain these pumps in good operating condition.
When production drops off, it is usually due to lower circulation rate. An approximation of this rate
can be made by several methods:
1.
Temperature drop across the heat exchanger.
2.
Visual inspection of flow in evaporator body.
3.
Testing the circulating pump.
11. Items (1) and (2) above are covered by the system designer.
5.3 Operation
42
Model AF (42"/1200mm/54"/60"/66") LM/LMR Bearings Installation, Operation, and Maintenance Manual
