Bypass-Piping Considerations - Goulds Pumps 3700 Installation, Operation And Maintenance Manual

Example: Discharge piping equipment
Correct
1. Bypass line
2. Shut-off valve
3. Check valve
4. Discharge isolation valve

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.
Model 3700, API Type OH2 / ISO 13709 1st and 2nd Ed. / API 610 8/9/10/11th Ed. Installation, Operation, and Maintenance
Manual
Incorrect
1. Check valve (incorrect position)
2. The isolation valve should not be positioned
between the check valve and the pump.
Installation
35