Bushings have multiple uses in the pump and seal business that include:
- To thermally isolate a pumping liquid from the pump stuffing box
- Located in the bottom of the stuffing box to stabilize a moving shaft.
- In an API (American Petroleum Institute) gland to support the shaft in the event of a bearing failure.
- To restrict the amount of flushing fluid flowing between the stuffing box and the rear of the impeller.
Most pump bushings are manufactured from carbon or Teflon®.
In recent years there have been many man made materials doing a good job of restricting fluid flow, reducing thermal conductivity, and reducing shaft radial movement in the stuffing box of centrifugal pumps.