Bypass-Piping Considerations; Auxiliary-Piping Checklist - 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.

Auxiliary-piping checklist

Precautions
WARNING:
• Cooling systems such as those for bearing lubrication and mechanical-seal systems must be
• Sealing systems that are not self-purging or self-venting, such as plan 23, require manual venting
NOTICE:
The mechanical seal must have an appropriate seal-flush system. Otherwise, excess heat
generation and seal failure can occur.
Model 3700, API Type OH2 / ISO 13709 1st and 2nd Ed. / API 610 8/9/10/11th Ed. Installation, Operation, and Maintenance
Manual
operating properly to prevent excess heat generation, sparks, and premature failure.
prior to operation. Failure to do so will result in excess heat generation and seal failure.
Incorrect
1. Check valve (incorrect position)
2. The isolation valve should not be positioned
between the check valve and the pump.
Installation
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