Goulds Pumps 3700 - IOM - Manual (Page 35)

Installation
Example: Discharge piping equipment
Correct Incorrect
1. Check valve (incorrect position)
1. Bypass line
2. The isolation valve should not be positioned
2. Shut-off valve
between the check valve and the pump.
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
operating properly to prevent excess heat generation, sparks, and premature failure.
• Sealing systems that are not self-purging or self-venting, such as plan 23, require manual venting
prior to operation. Failure to do so will result in excess heat generation and seal failure.
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 33
Manual