Grundfos NK Serie Instrucciones De Instalación Y Funcionamiento página 26

Starting the pump with new packing rings
Packing rings require lubrication. Therefore, the stuffing box must
always be allowed to leak 40 to 60 drops per minute. Never
overtighten the stuffing box gland.
For suction lift applications, it can be necessary to slightly
overtighten the gland while starting the pump to avoid air from
entering the pump. Air in the pump in this situation will result in
the pump being unable to draw the liquid to the pump.
Loosen the gland immediately when the pump delivers liquid
allowing a leakage of 40 to 60 drops per minute. Readjust after a
few hours of operation if leakage increases.
11.1.4 Shaft sleeve replacement
The shaft sleeve can be worn out as the sleeve life depends on
the application. When the leakage is too high even with new
packing rings in combination with a slight overtightening, the shaft
sleeve needs to be replaced.
11.2 Lubrication of bearings in bearing bracket
11.2.1 Grease-lubricated bearings
Pump with greased-for-life bearings
Fig. 30 Bearing bracket with closed, greased-for-life bearings
The bearing bracket with closed, greased-for-life bearings is
maintenance-free. Under optimum operating conditions, the
bearing life will be approx. 17,500 operating hours. After that
period, it is advisable to replace the bearings. See section
13.1 Service kits.
To check the bearings, regularly listen to them by
Note means of a solid rod. There are no SPM measuring
points for this type of bearing bracket.
26
Pump with lubrication nipples or automatic grease
lubricators
Fig. 31 Bearing bracket with open roller bearing and double
angular contact bearing lubricated via grease nipples
Fig. 32 Bearing bracket with open roller bearing and double
angular contact bearing lubricated via automatic
grease lubricators
If the pump has grease nipples or automatic grease lubricators,
the grease in the bearings must be renewed during the whole life
time.
Under optimum operating conditions, the bearing life will be
approx. 100,000 operating hours. After that period, it is advisable
to replace the bearings. See section
bearings must be filled with grease according to Grundfos
specifications. Clean up all the used grease in the bearing
bracket before replacing the new bearing.
Automatic grease lubricators
Replace lubricators every 12 months. When replacing the
lubricators, follow this procedure:
1. Remove the main drain plug, see fig. 33, in the bottom of the
bearing bracket for one hour during operation to remove old
and excess grease.
2. Fit the new lubricators on top of the bearing bracket and set
them to empty within 12 months according to the instruction
supplied with the lubricators.
3. Refit the main drain plug in the bottom of the bearing bracket.
Grundfos recommends SKF SYSTEM 24 lubricators, type LAGD
125/HP2 or LAGD 60/HP2.
Quantity
2 x LAGD 125/HP2
2 x LAGD 60/HP2
13.1 Service kits. New
Product number
96887371
97776374