Goulds Pumps IC - IOM - Manual (Page 37)

Check Explanation/comment Checked
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
illustrations.
If increasers are used, check that they
are installed between the pump and the
check valve.
See Example: Discharge piping equipment for
illustrations.
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
between the check valve and the pump.
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.
When a minimum-flow orifice is unavailable
Consider an automatic recirculation control valve or solenoid-operated valve if a constant bypass
(minimum-flow orifice) is not possible.
Installation
Model IC, ICI, ICH, ICIH Installation, Operation, and Maintenance Manual 35