Split Case Horizontal Pumps
Most split-case horizontal pumps are designed with a shaft bearing pedestal located at both ends of the shaft and an impeller (s) in the middle. Both sides of the impeller are (loosely) supported by wear rings and, as the name implies, they do wear.
This design, unlike sidewall agitators, locates the overhang in the middle, creating shaft sag. The weight of the impeller at the greatest point of sag exacerbates this phenomenon, and the shaft exhibits eccentric movement to the bore, making sealing all the more difficult. Any throttling of suction or discharge lines makes effective sealing nearly impossible.
The patented PackRyt® system for split-case pumps includes a bearing/lantern ring (BLR) and specific, patented SealRyt® packings for each side. The BLR eliminates the shaft sag in the sealing areas and, due to constant retention of concentric shaft movement, makes the sealing area immune to the effects of throttling. The shaft radial pattern thus controlled, the specific packings can better achieve their functions- heat transfer and leakage elimination.
For split-case horizontal pumps with more than one impeller, please contact SealRyt® Engineering for a short conversation on piping and pressure differentials to achieve maximum service life.