Cl/ CV/ DEL/ DEV Tank O-Ring
Product Overview
A proven choice for sealing Pentair Clean & Clear and FNS Plus filter tanks when the original gasket begins to weep or flatten.
The Super-Pro O-524-9 is the standard specification for technicians servicing Pentair Cl, CV, DEL, and DEV series filters. This heavy-duty mechanical gasket provides the critical seal between the upper and lower tank halves, preventing pressure loss and external leaks. In our experience, high-mineral water or extreme heat can cause rubber gaskets to compress over time, making this a vital replacement part for maintaining system pressure.
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Benefits & What Makes It Different
Precision Fit for Pentair Tanks
Specifically engineered to match the dimensions required for Cl, CV, DEL, and DEV filter housings, ensuring a reliable seal under high pressure.
Chemical-Resistant Synthetic Rubber
Constructed from durable materials that resist degradation from chlorine and acid, extending the service life of your filtration system compared to generic alternatives.
Restores System Integrity
By maintaining a tight seal at the tank flange, the O-524-9 ensures your pump's flow is directed entirely through the filter media rather than escaping through the clamp.
Compatibility
- Pentair Clean & Clear Plus (CCP/CV) Filters
- Pentair FNS Plus (DEL/DEV) DE Filters
- Pentair Clean & Clear (CC) Filters
When To Use This
Pro Tip
Always clean the tank flange and the O-ring groove thoroughly with a damp cloth before installing the new O-524-9; even a single grain of sand or dried DE can prevent a perfect seal and lead to a slow drip.
Common Questions & Instructions
How do I know if my Pentair filter tank O-ring needs to be replaced?
Look for water weeping from the center clamp assembly or visible signs of the O-524-9 being flattened, cracked, or stretched. If the O-ring no longer sits snugly in the groove or leaves black residue on your hands, it is time for a replacement to prevent air leaks.
Can I use any lubricant on the O-524-9 tank gasket?
No, you should only use a silicone-based lubricant; petroleum-based products like Vaseline will cause the rubber to swell and degrade prematurely. Proper lubrication helps the O-ring seat correctly and prevents it from pinching when the metal clamp is tightened.
Is this O-ring compatible with both DE and Cartridge filters?
Yes, this part is designed for the Pentair Clean & Clear Plus cartridge filters (CV) as well as the FNS Plus (DEL/DEV) DE filters, making it a versatile staple for many residential and commercial equipment pads.
Delivered today to your DFW neighborhood
Order this item by 2 PM Central on a weekday, and we'll have it on your driveway by evening. Same-day delivery is FREE to every ZIP in our DFW coverage area — no minimum — or it's free with our weekly service plan.
