Sta-Rite / Berkeley / Pentair Diffuser C21-10 — Gasket / Seal Ring

Pre-cut diffuser seal ring (C21-10) is a direct replacement component designed for use in Sta-Rite, Berkeley, and Pentair pump systems to maintain proper flow and performance. Sized to seat cleanly on the diffuser for even compression and a leak-tight seal during service or rebuilds.

Cross-reference / Names:

• Part: C21-10 Diffuser

• Also called: Diffuser gasket / seal ring

Compatibility:

• Motor range: ~1–2.5 HP diffuser applications

• Pump families: Sta-Rite / Berkeley / Pentair equivalents

• Also used on: Anthony centrifugal pool pumps (select models)

Why this part:

• Direct-fit profile for quick, reliable installs

• Consistent thickness for uniform sealing pressure

• Smooth edges for easier alignment and reassembly

Explore our full lineup of Pre-cut Gaskets.   

Looking for more? Check out our Shaft Seals, Pump Repair Kits , & Parts/Accessories 

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