In brief: Pack of ten Pentair seals for salt chlorination systems. Pentair part number 521147.
Cell union seals, pack of ten
Each salt cell connects via two unions, each fitted with an O-ring. These seals are removed several times per season for cell inspection and descaling.
They harden due to the combined effects of chlorine produced on site, limescale deposits, and compression cycles. A hardened seal does not return to its original shape and starts to seep.
The pack of ten is a practical choice: these seals are inexpensive and need frequent replacement, so it is better to keep some on hand than to postpone a cell inspection because you are missing a seal.
Official Pentair specifications
| Part number |
521147 |
| Quantity |
10 seals |
| Application |
Pentair salt chlorination systems |
| Genuine part |
Yes, Pentair part |
Frequently asked questions
When should they be replaced?
Whenever a seal is flattened, hardened, or scaled. In practice, once per season for a regularly inspected cell.
What grease should I use?
A thin layer of silicone pool grease. Never use petroleum jelly or petroleum-based grease: they damage elastomers.
Why are my seals scaling up?
Limescale deposits on cell seals generally indicate hard water or a pH that is too high. Correcting the water balance extends the life of the seals and the cell.
Service on the North Shore
Piscines Geyser keeps Pentair parts in stock in Blainville and serves the Laurentians. Send us a photo of your installation if you are unsure whether the part is compatible: we will confirm before shipping.
