Pentair Square Ring Closure O-Ring 8-1/2" | Triton C-3 Sand Filter & Challenger Pump | 152509Z
- In stock, ready to ship
- Backordered: contact us for ETA
- SKU:
- 152509Z
-
Poolaroo Promise
- Fast Shipping — Ships in 1–2 Business Days
- 30-Day Risk-Free Returns — We Pay Return Shipping, No Restocking Fees
- Powered By People Who Care - No Faceless Conglomerate
About This Item
The Pentair Square Ring Closure (152509Z) is the OEM replacement closure O-ring for the Pentair Triton C-3 Sand Filter and Challenger High Flow Pump lines. This single square-profile ring seals the filter or pump closure, preventing bypass and pressure loss at the tank or pump lid junction.
⚠️ IMPORTANT: FILTER MANUFACTURING DATE — TWO VARIANTS EXIST
This square ring is confirmed for Triton C-3 Sand Filters manufactured before March 1997 and after March 1997. If your Triton C-3 falls within those production windows, this is the correct ring. Verify the part number stamped or molded on your original ring before ordering.
⚠️ IMPORTANT: CHALLENGER PUMP — 5 HP ONLY
For the Challenger High Flow Pump (CFII-N1-5FE), this 8-1/2" square ring is confirmed for the 5 HP model only. If you have a different Challenger HP rating, verify your pump's part number before ordering.
The closure square ring forms the primary pressure seal between the filter tank halves or pump lid and body. A degraded or flattened square ring allows pressurised water to escape at the closure seam, resulting in visible leaks, reduced system pressure, and potential air entrainment. Because this is a square-profile (not round-profile) ring, substituting a standard O-ring of the same inside diameter will not produce an adequate seal — the square cross-section is a design-specific requirement of these closure assemblies.
Specifications
| Pentair Part Number | 152509Z |
| Part Type | Square ring — closure seal |
| Inside Diameter | 8-1/2" |
| Quantity Included | 1 (Each) |
Fits Into
| Brand | Equipment Line | Model / Part Number | Notes |
| Pentair | Triton C-3 Sand Filter | TR100C-3 | Used on filters manufactured before 3-97 and after 3-97 |
| Pentair | Triton C-3 Sand Filter | TR140C-3 | Used on filters manufactured before 3-97 and after 3-97 |
| Pentair | Triton C-3 Sand Filter | TR 100C-3 | Used on filters manufactured before 3-97 and after 3-97 |
| Pentair | Triton C-3 Sand Filter | TR 140C-3 | Used on filters manufactured before 3-97 and after 3-97 |
| Pentair | TR Series Sand Filter | TR100C | — |
| Pentair | TR Series Sand Filter | TR140C | — |
| Pentair | Challenger High Flow Pump | CFII-N1-5FE | 5 HP model only — 8-1/2" square ring |
Compatibility is based on Pentair parts documentation and available OEM records. This is not an exhaustive list. For certainty, verify the part number in your equipment's manual or on the original part itself before ordering.
Pro Tip
Square rings compress differently from round O-rings — if the ring shows any flat spots, cracking, or has taken a permanent set in the groove, replace it before reassembling the closure. When you have the closure open, inspect the mating sealing surface on both the tank band and the flange for scoring or debris that could prevent a full seal even with a new ring. Apply a thin coat of Pentair-approved O-ring lubricant to the ring before reinstallation to ease seating and extend service life.
