Goulds Pumps 3796 i-FRAME - IOM - Manual (Page 61)

NOTICE:
Make sure to lubricate the packing. Failure to do so may result in shortening the life of the packing and the
pump.
You must use an external sealing liquid under these conditions:
• The pumped fluid includes abrasive particles.
• The stuffing-box pressure is below atmospheric pressure when the pump is running with a suction lift
or when the suction source is in a vacuum. Under these conditions, packing is not cooled and
lubricated and air is drawn into pump.
Conditions for application of an external liquid
If... Then...
The stuffing box pressure is above atmospheric
pressure and the pumped fluid is clean.
Normal gland leaks of 40 to 60 drops per minute is
usually sufficient to lubricate and cool the packing.
You do not need sealing liquid.
The stuffing box pressure is below atmospheric
pressure or the pumped fluid is not clean.
An outside source of clean compatible liquid is
required.
An outside source of clean compatible liquid is
required.
You must connect the piping to the lantern ring
connection with a 40 to 60 drops-per-minute leak
rate. The pressure must be 15 psi (1.01 kg/cm 2 )
above the stuffing box pressure.
Pump priming
Pump priming with the suction supply below the pump (3796)
Model 3796 is self-priming and does not require a foot valve in the suction line or manual priming prior to
startup (except for the initial charge). However, in a pressurized system, the pump requires an air vent or a
permanent bypass line in the discharge piping to vent the evacuated air.
This illustration is an example of priming a 3796 pump in a pressurized system.
3796 Priming in a
Pressurized System
1
2
3
4
5 6
7
1. By-pass line
2. Concentric reducer
3. Long radius elbow
4. Shutoff valve
5. Strainer
6. Foot valve (if used)
7. Discharge isolation valve
Figure 16: Priming a 3796 pump
Commissioning, Startup, Operation, and Shutdown (Continued)
Model 3796 i-FRAME Installation, Operation, and Maintenance Manual 59