Pentair Seal Plate Cord Ring | Dyna-Pro / Dyna-Pro E Inground Pump | U9-373Z

The Pentair Seal Plate Cord Ring (U9-373Z) is the OEM replacement seal plate O-ring for the Pentair Dyna-Pro and Dyna-Pro E inground pump series, covering 1/2 through 2-1/2 HP models.

⚠️ 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 cord ring seals the interface between the seal plate and the pump housing on Dyna-Pro and Dyna-Pro E inground pumps. A deteriorated or compressed seal plate cord ring allows water to bypass the seal plate joint, leading to air ingestion, loss of prime, and potential water intrusion toward the motor. Replacing this ring at each pump service interval maintains the pressure integrity of the wet end assembly.

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

When servicing the seal plate, inspect the mechanical shaft seal at the same time — both components are exposed during disassembly and wear on similar intervals. Before installing this cord ring, apply a thin coat of Pentair R172351 Lifeguard® Silicone Lubricant to seat it evenly and prevent tearing during reassembly. Never use petroleum-based lubricants — they will degrade the rubber and shorten service life. For lubrication details, see the note above — the correct product is linked there.