Goulds Pumps 3700 - IOM - Manual (Page 51)

Commissioning, Startup, Operation, and Shutdown
Shaft sealing with a mechanical seal
Precautions
WARNING:
The mechanical seal used in an Ex-classified environment must be properly certified. Prior to startup,
make sure that all areas that could leak pumped fluid to the work environment are closed.
NOTICE:
• The mechanical seal must have an appropriate seal-flush system. Otherwise, excess heat
generation and seal failure can occur.
• 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.
Shipping
Pumps may be shipped with or without a mechanical seal installed.
Cartridge-type mechanical seals
Cartridge-type mechanical seals are commonly used. Cartridge seals are preset by the seal
manufacturer and require no field settings. Cartridge seals installed by the user require
disengagement of the holding clips prior to operation, allowing the seal to slide into place. If the
seal has been installed in the pump by ITT, these clips have already been disengaged.
Other mechanical seal types
For other types of mechanical seals, refer to the instructions provided by the seal manufacturer
for installation and setting.
Connection of sealing liquid for mechanical seals
Seal lubrication is required
Seal faces must have liquid film between them for proper lubrication. Locate the taps using the
illustrations shipped with the seal.
Seal flushing methods
You can use these methods in order to flush or cool the seal:
Method Description
Product flush Run the piping so that the pump pushes the pumped fluid from the casing and
injects it into the seal gland. If necessary, an external heat exchanger cools the
pumped fluid before it enters the seal gland.
External flush Run the piping so that the pump injects a clean, cool, compatible liquid directly into
the seal gland. The pressure of the flushing liquid must be 5 to 15 psi (0.35 to 1.01
kg/cm
2 ) greater than the seal chamber pressure. The injection rate must be 0.5 to
2 gpm (2 to 8 lpm).
Other You can use other methods that employ multiple gland or seal chamber
connections. Refer to the mechanical seal reference drawing and piping diagrams.
Pump priming
Prime the pump with the suction supply above the pump
1. Slowly open the suction isolation valve.
Model 3700, API Type OH2 / ISO 13709 1st and 2nd Ed. / API 610 8/9/10/11th Ed. Installation, Operation, and Maintenance 49
Manual