Goulds Pumps 3700 Installation, Operation And Maintenance Manual page 33

Check
If more than one pump operates
from the same liquid source,
check that separate suction-piping mance.
lines are used for each pump.
If necessary, make sure that the
suction piping includes a drain
valve and that it is correctly in-
stalled.
Liquid source below the pump
Check
Make sure that the suction piping This helps to prevent the occur-
is free from air pockets.
Check that the suction piping
slopes upwards from the liquid
source to the pump inlet.
If the pump is not self-priming,
check that a device for priming the that is at least equivalent to the
pump is installed.
Liquid source above the pump
Check
Check that an isolation valve is
installed in the suction piping at a during pump inspection and main-
distance of at least two times the
pipe diameter from the suction
inlet.
Make sure that the suction piping This helps to prevent the occur-
is free from air pockets.
Check that the piping is level or
slopes downward from the liquid
source.
Make sure that no part of the
suction piping extends below the
suction flange of the pump.
Make sure that the suction piping This prevents air from entering the
is adequately submerged below
the surface of the liquid source.
Example: Elbow close to the pump suction inlet
Correct
The correct distance between the inlet flange of the
pump and the closest elbow must be at least five
pipe diameters.
Model 3700, API Type OH2 / ISO 13709 1st and 2nd Ed. / API 610 8/9/10/11th Ed. Installation, Operation, and Maintenance
Manual
Explanation/comment
This recommendation helps you to
achieve a higher pump perfor-
—
Explanation/comment
rence of air and cavitation in the
pump inlet.
—
Use a foot valve with a diameter
diameter of the suction piping.
Explanation/comment
This permits you to close the line
tenance.
Do not use the isolation valve to
throttle the pump. Throttling can
cause these problems:
• Loss of priming
• Excessive temperatures
• Damage to the pump
• Voiding the warranty
rence of air and cavitation in the
pump inlet.
—
—
pump through a suction vortex.
Incorrect
Installation
Checked
Checked
Checked
31