Goulds Pumps 3355 - IOM - Manual (Page 25)

Installation
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.
Discharge piping checklist
Checklist
Check Explanation/comment Checked
Check that an isolation valve is in- The isolation valve is required for:
stalled in the discharge line. • Priming
• Regulation of flow
• Inspection and maintenance of the pump
Check that a check valve is installed in The location between the isolation valve and the
the discharge line, between the isola-
pump allows inspection of the check valve.
tion valve and the pump discharge The check valve prevents damage to the pump and
outlet. seal due to the back flow through the pump, when
the drive unit is shut off. It is also used to restrain
the liquid flow.
If increasers are used, check that they
are installed between the pump and
the check valve.
If quick-closing valves are installed in
This protects the pump from surges and water
the system, check that cushioning de- hammer.
vices are used.
Final piping checklist
Check Explanation/comment Checked
Check that the shaft rotates Rotate the shaft by hand. Make
smoothly. sure there is no rubbing that can
lead to excess heat generation or
sparks.
Model 3355 Installation, Operation, and Maintenance Manual 23