Goulds Pumps 3298 - IOM - Manual (Page 35)

Installation
Example: Installation for expansion
Correct Incorrect
1. Expansion loop/joint
Suction-piping checklist
Performance curve reference
CAUTION:
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.
Net positive suction head available (NPSH
A
) must always exceed NPSH required (NPSH
R
) as
shown on the published performance curve of the pump.
If a suction lift over 10 ft. (3 m) and a liquid temperature higher than 120°F (49°C) are required,
then read the pump performance curve for the NPSH
R
.
Suction-piping checks
Check Explanation/comment Checked
Flush all suction piping before you This reduces the risk of pump
connect it to the pump.
operation problems.
Check that the distance between This minimizes the risk of cavita-
the inlet flange of the pump and tion in the suction inlet of the
the closest elbow is at least two pump due to turbulence.
pipe diameters. See the Example sections for il-
lustrations.
Check that elbows in general do See the Example sections for il-
not have sharp bends. lustrations.
Check that the suction piping is The suction piping must never
one or two sizes larger than the have a smaller diameter than the
suction inlet of the pump. suction inlet of the pump.
Install an eccentric reducer be- See the Example sections for il-
tween the pump inlet and the lustrations.
suction piping.
Check that the eccentric reducer
See the example illustrations.
at the suction flange of the pump
has the following properties:
• Sloping side down
• Horizontal side at the top
3298 Family Installation, Operation, and Maintenance Manual 33