Discharge Piping Checklist; Bypass-Piping Considerations - ITT 3610 i-FRAME Manual

4.6 Piping checklists
Liquid source above the pump
Check
Check that an isolation valve is installed in
the suction piping at a distance of at least
two times the pipe diameter from the suc-
tion inlet.
Make sure that the suction piping 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 pip-
ing extends below the suction flange of the
pump.
Make sure that the suction piping is ade-
quately submerged below the surface of
the liquid source.

4.6.3 Discharge piping checklist

Checklist
Check
Check that an isolation valve is installed in
the discharge line. For specific gravity less
than 0.60, minimize distance from pump
discharge.
Check that a check valve is installed in the
discharge line, between the isolation valve
and the pump discharge outlet.
If increasers are used, check that they are
installed between the pump and the check
valve.
If quick-closing valves are installed in the
system, check that cushioning devices are
used.

4.6.4 Bypass-piping considerations

When to use a bypass line
Provide a bypass line for systems that require operation at reduced flows for prolonged periods. Connect
a bypass line from the discharge side (before any valves) to the source of suction.
When to install a minimum-flow orifice
You can size and install a minimum-flow orifice in a bypass line in order to prevent bypassing excessive
flows. Consult your ITT representative for assistance in sizing a minimum-flow orifice.
36 3610 i-FRAME API 610 11th Ed/ISO 13709 2nd Ed, API Type BB1 Single-Stage, Axially-Split, Between-Bearing IOM
Explanation/comment
This permits you to close the line during pump inspec-
tion and maintenance.
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
This helps to prevent the occurrence of air and cavita-
tion in the pump inlet.
—
—
This prevents air from entering the pump through a
suction vortex.
Explanation/comment
This protects the pump from surges and water hammer.
Checked
Checked