How to Replace a Packing (1)
Why to Replace
As we mentioned in the last article Sanitary Pumps Sealing-Packing, packing contains in itself some lubricant to reduce the friction. Under normal conditions, the packing is placed under pressure which will, along with the heat generated by friction, cause the lubricant to be squeezed out of the packing. As the lubricant is reducing, the packing will be worn down by the shaft and decline in tightness and sealing ability. Therefore it is a must to replace the packing at certain time.
When to Replace
Generally speaking, if you can no longer well control the leakage by tightening the packing gland with a simple end wrench, it's time to replace the packing.
How to Replace
The process of replacing packing replacement involves the following steps: selecting the proper tools, shutting down the pump, removing the old packing, checking the pump conditions, installing the new packing and start-up.
Selecting the Proper Tools
A good packing installation will require the following special tools.
- Paper knife to cut the packing.
- Split sleeve or wooden blocks for seating the packing.
- Packing hooks to remove the old packing.
- Flashlight to help find the lantern ring and to line up the lantern ring.
- Mirror to help find the lantern ring
- Packing lubricant, such as Teflon or silicone grease to allow you to pre-lube the packing. This will reduce the probability of packing failure during the crucial startup period.
Pump Shutdown
Shut off the power and lockout the pump. Do not forget the padlock and accident prevention tag (OSHA 29 CFR1910.147). If the volute case is under pressure, you should shut off the water at both the inlet and outlet of the pump.
Remove the Old Packing
Remember to check the bolts and nuts. If they are damaged, you should also repair or replace them. Remove all the old packing with a packing hook and one ring at a time, including the lantern ring. While removing the lantern ring, you should first locate the holes in its sides (using the mirror and flash light), insert the packing hook into each of the two holes and pull out the lantern ring from the stuffing box.
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