ITT Goulds Pumps XHD, Installation, Operation And Maintenance Manual

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Installation
XHD Installation, Operation, and Maintenance Manual 38
Example: Discharge piping equipment
Correct Incorrect
1. Bypass line
2. Shut-off valve
3. Check valve
4. Discharge isolation valve
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.