Aqua Flow Service Associates, Inc.
Serving all of your pump needs since 1988
How to re-pack and / or adjust packing leak-off rate
How to re-pack and / or adjust leak-off rate (GENERAL NOTES)
1. Isolate the pump both mechanically and electrically.
2. Remove the old packing from the stuffing box. Do not throw old packing away until it is properly examined and failure is determined. { See note #1 below}
3. Use the correct cross-section of packing or die-formed rings compatible with the pump rating and fluid being used.
4. When using coil or spiral packing, always cut the packing into individual rings.
5. Install packing rings one-at-a-time. Gently "snug" the rings together, staggering the joints 90 degrees apart.
6. If a lantern ring is used, be sure to position it directly beneath the circulation port.
{ Consult pump manufacturer for further details }
7. After installing the last ring, tightened the gland bolts with the gland in place, finger tight. It is now that you will open the isolation valves and close the electrical connections to run the pump.
Fluid should be flowing out of the gland area at a substantial rate with the pump not running.
*8. Energize the pump. Slowly tighten the gland bolts evenly until a tolerable leak-off rate is achieved. STOPPING THE LEAKAGE COMPLETELY AT THIS POINT WILL BURN THE PACKING AND POSSIBLY DAMAGE THE SHAFT AND / OR THE SHAFT SLEEVES.
9. Allow the packing to leak freely for the first four to six hours of operation. This will ensure a longer packing life. After that time, gradually take up he gland evenly until leakage is at a proper level. A good rule of thumb is 8 to 10 drops per minute per inch of shaft diameter. (Please consult operator's manual for exact rates)
10. When specified, provide means of lubrication through the lantern ring port at 5 to 10 psi greater then discharge pressure.
11. Replace packing when leakage can not be controlled by further take-up of the gland.
Note #1. The old Packing gives clues to the cause of failure. Examining the packing and determining the failure will identify the pump's condition which will help eliminate additional down time and repair cost.
Note (*) This is the point at which Aqua Flow Service relinquishes the packing's adjustments to the own of the equipment.
{ Manufacturer's recommendations may supersede all the above. When in doubt, refer to the owners manual or pump representative. }
GOOD RULES OF THUMB ON ADJUSTING PACKING
With the pump running, each gland should be tightened equally on each of the nuts, about one "flat" ( 2 nuts on each side). Each gland could have different amounts of adjustments needed to have optimal leak off rates, this is not uncommon. Then give it a few minutes to adjust inside the pump. This may slow down the leak-off rate. If not, try another "flat" of the nuts. Do this until the leak-off rate is acceptable and the glands remain cool. If the glands get to hot, back each nut off until you start cooling the gland and repeat the steps. This could take several tries. Eight (8) hours of run time during the adjustment is not uncommon. If you must stop the pump during this adjustment, this is not a problem. Just pick pick up where you left off the next time. Even if you adjust it one day, you may have to adjust the packing the next run time. Corrosion buildup, pressure, flow water quality, etc., can have an effect on the leak off rate.
PATIENCE IS THE KEY
The more time we take in adjusting the leak-off rate, it is more likely that the packing will last a longer time. If it takes several run periods to achieve this, then so be it. Do not try and ruch this process, You could "smoke" the packing, score the shafting, or worse cut the shaft in two.
If you should have any questions at all, please feel free to give one of our helpfull technicains a call.
