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Mechanical Seal 3866 (PS-3866) — 5/8″

ps-100 , ps-200 , ps-201 mechanical seal- buy now!

Mechanical Seal 3866 (PS-3866) — 5/8″

Weight 1 lbs
Dimensions 8 × 6 × 4 in
QTY Price

$6.25
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  • DESCRIPTION

    Mechanical Seal 3866 — Type 166 / T-16 (5/8″) | PS-3866 Equivalent

    Equal to industry standard 3866 / PS-3866.
    Direct-fit Type 166 / T-16 single-spring seal for pool/spa and small-pump applications—upgraded with Viton elastomers and a machined carbon/ceramic face set for longer service life.

    At-a-glance specs: 5/8″ shaft • 1.187″ × 0.343″ cup seat • Machined carbon/ceramic faces • Viton(FKM) elastomers

    Why choose 3866 (PS-3866):

    • T-16 footprint for quick, drop-in replacement

    • Viton handles higher chlorine, heat, and chemicals better than Buna

    • Machined carbon face for smoother sealing vs. molded carbon

    Upgrades / Alternatives (same footprint):

    • 100 — Basic (Buna)

    • 957 — Premium carbon face (Buna)

    • 100cv — Molded carbon

    • 100cvss — Silicon Carbide / Silicon Carbide / Viton

    Explore our full lineup of Single Spring Seals—PS replacements, pool/spa seals, and our SPS line.

    Looking for more? Shop Pump Repair Kits, Parts & Accessories, and Pre-Cut Gaskets.

    Have questions? Check out our Pool/Spa Small Pump Guide or call us anytime—we’re here to help.

    Please click “specifications” below for OEM numbers and Pump Nameplate Data
  • SPECIFICATIONS
    Cross references & alternative part numbers

    OEM numbers: 4547 , 17351-0102

    Brands: Anthony & Sylvan Corporation , Pentair Pool Products

    Nameplate Data: AJ Series , L-Series™

    Also known as / searched as

    • PS-3866 mechanical seal

    • 3866 mechanical seal

    • PS3866 seal / PS 3866 seal

    • Type 166 mechanical seal 5/8

    • T-16 mechanical seal

    • pool pump mechanical seal 5/8

    • spa pump mechanical seal 5/8

    • machined carbon ceramic pump seal Viton / FKM

    • Replacement style commonly referenced alongside Type 16, G, A, 6, AV, 2100 (verify size/fitment)

  • PHYSICAL PROPERTIES

    Seal House Type 166
    Our Type 166 configuration combines the best design elements we’ve refined over the years to deliver superior reliability and performance.

    Key advantages include:

    • Crimped rotary face with positive drive — securely held in place to prevent dislodgement during installation.

    • Full metal retainer with positive drive — ensures strength and long-term durability.

    • Full rubber bellows construction — provides complete sealing along both the shaft and face, rather than relying on a small O-ring or partial gasket.

    • Quality materials — delivers extended service life.

    Compatibility & upgrade:

    The Type 166 is designed to replace most small seal types commonly used in pool and spa applications, including Type 16, G, A, 6, AV, 2100, and more. Even in its basic form, this seal is a significant upgrade over standard “pool” seals typically available on the market.

Disclaimer: Seal House USA provides aftermarket replacement parts. Any OEM names are used strictly for cross-reference. We are an independent supplier.

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