For this reason, and especially for larger pumps using packing glands, there will usually be a shaft sleeve
that can be slipped over the shaft. The wear down will then occur only on the shaft sleeve. This can be replaced instead of the more expensive shaft.

  Another disadvantage of using packing glands is the fact that there is a certain amount of skill needed for cutting and installing the gland in order for it to work properly. It's more difficult to get consistent results.

  Although there are disadvantages in using gland packing, there are also good reasons for using them.

  They are less expensive to use compared to mechanical seals. If chosen and installed correctly, they can last for a very long time. When changing packing glands, the pump housing need not be opened up. This can be an advantage when skilled labor is in short supply.

  Keeping stock of spares is not a problem because they can be used for all pump brands as long as they have the same gland sizes. Pump packing materials are more robust compared to the fragile and delicate mechanical seals.

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