4.6.3 Discharge piping checklist
Checklist
Check
Explanation/comment
Checked
Check that an isolation valve is installed in
the discharge line. For specific gravity less
than 0.60, minimize distance from pump
discharge.
The isolation valve is required for:
•
Priming
•
Regulation of flow
•
Inspection and maintenance of the pump
•
Reduce risk of pumpage vaporization and vapor
locking at low flow rates for low specific gravity liq-
uids.
See Example: Discharge piping equipment for illustra-
tions.
Check that a check valve is installed in the
discharge line, between the isolation valve
and the pump discharge outlet.
The location between the isolation valve and the pump
allows inspection of the check valve.
The check valve prevents damage to the pump and 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.
See Example: Discharge piping equipment for illustra-
tions.
If increasers are used, check that they are
installed between the pump and the check
valve.
See Example: Discharge piping equipment for illustra-
tions.
If quick-closing valves are installed in the
system, check that cushioning devices are
used.
This protects the pump from surges and water hammer.
Example: Discharge piping equipment
Correct
Incorrect
1
2
3
4
1.
Bypass line
2.
Shut-off valve
3.
Check valve
4.
Discharge isolation valve
2
1
1.
Check valve (incorrect position)
2.
The isolation valve should not be positioned be-
tween the check valve and the pump.
4.6 Piping checklists
Model 3700, 3703, 3710, 3700LF, 3700LFI API Type OH2 / ISO 13709 1st and 2nd Ed. / API 610 8/9/10/11th Ed. Instal-
lation, Operation, and Maintenance Manual
35
Summary of Contents for Goulds Pumps 3700
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