Goulds Pumps 3610 - IOM - Manual (Page 44)

Commissioning, Startup, Operation, and Shutdown
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
WARNING:
These pumps are not self priming and must be fully primed at all times during operation. Loss of prime
can lead to excessive heat and severe damage to the pump and seal.
WARNING:
A build-up of gases within the pump, sealing system, or process piping system may result in an explosive
environment. Make sure the process piping system, pump and sealing system are properly vented prior to
operation.
Before the pump is started, the pump must be fully primed and the suction pipe must be full of
liquid. If pump is run dry, then rotating parts within the pump can seize to stationary parts
because they depend upon the pumped liquid for lubrication. Several methods of priming can
be used depending upon the type of installation and service involved.
Prime the pump with the suction supply above the pump
This method of priming the pump is simplest and safest. A float switch in the suction reservoir
can be arranged to stop the pump if there is a failure of liquid supply.
1. Open the suction gate valve and close the discharge gate valve.
2. Remove the vent plug until all air is expelled and water flows through openings.
3. Close the air vent valves, start the pump, and open the discharge gate valve.
The pump will continue to be primed for any future starting.
42 Installation, Operation, and Maintenance Manual