Goulds Pumps XHD - IOM - Manual (Page 38)

Installation
Check Explanation/comment Checked
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.
Suction pipe reducers should
have no more than two pipe diam-
eter changes per reducer.
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
If suction strainers or suction bells Suction strainers help to prevent
are used, check that they are at
clogging.
least three times the area of the Mesh holes with a minimum diam-
suction piping. eter of 1/16 in. (1.6 mm) are
recommended.
If more than one pump operates This recommendation helps you to
from the same liquid source, achieve a higher pump perfor-
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 Explanation/comment Checked
Make sure that the suction piping This helps to prevent the occur-
is free from air pockets. rence of air and cavitation in the
pump inlet.
Check that the suction piping —
slopes upwards from the liquid
source to the pump inlet.
If the pump is not self-priming,
Use a foot valve with a diameter
check that a device for priming the that is at least equivalent to the
pump is installed.
diameter of the suction piping.
Liquid source above the pump
Check Explanation/comment Checked
Check that an isolation valve is This permits you to close the line
installed in the suction piping at a during pump inspection and main-
distance of at least two times the tenance.
pipe diameter from the suction Do not use the isolation valve to
inlet. throttle the pump. Throttling can
cause these problems:
• Loss of priming
• Excessive temperatures
• Damage to the pump
• Voiding the warranty
Make sure that the suction piping This helps to prevent the occur-
is free from air pockets. rence of air and cavitation in the
pump inlet.
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 pump through a suction vortex.
the surface of the liquid source.
36 XHD Installation, Operation, and Maintenance Manual