Pentair Bulkhead O-Ring | Clean & Clear Plus, FNS Plus, Quad D.E. Filters | 86006900Z

The Pentair 86006900Z is the OEM replacement bulkhead O-ring for the Clean & Clear Plus cartridge filter series, FNS Plus D.E. filter series, and Quad D.E. filter series — serving as both the upper and lower bulkhead seal depending on the model and production date.

⚠️ IMPORTANT: DATE-OF-MANUFACTURE DETERMINES FITMENT
Fitment for Clean & Clear Plus filters depends on when your filter was manufactured. This O-ring fits units built before November 1998 (lower bulkhead position) and units built after October 2004 (upper and lower bulkhead positions). Filters manufactured between November 1998 and October 2004 use a different bulkhead O-ring. Check your filter's serial tag or equipment manual to confirm your production date before ordering.

⚠️ IMPORTANT: LUBRICATION REQUIRED — SOLD SEPARATELY
Always lubricate this O-ring with a silicone-based lubricant before installation. We carry the Pentair R172351 Lifeguard® Silicone Lubricant — the OEM-matched product for Pentair equipment.

This O-ring seals the bulkhead fitting where plumbing connections pass through the filter tank wall. A failed or flattened bulkhead O-ring allows water to bypass the seal at the connection point, resulting in leaks at the fitting and potential pressure loss. Replacing this O-ring restores a watertight seal at the bulkhead and is a standard service item whenever the bulkhead fitting is disturbed or the filter is opened for service.

Specifications

Fits Into

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

The date-of-manufacture qualification on Clean & Clear Plus filters is critical — this O-ring does not fit all production runs. Check the serial tag on your filter tank for the manufacture date before ordering. For the Quad D.E. series, the fit notes reference O-ring designation 2-329 at the bulkhead RPM position — confirm this matches the designation on your existing O-ring. When you have the filter open, apply a thin, even coat of Pentair R172351 Lifeguard® Silicone Lubricant to the O-ring before seating it in the groove. This prevents tearing during reassembly and ensures a full, even seal. Never use petroleum-based lubricants — they will degrade the O-ring and cause premature failure.