1. Mechanical Seals
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Mechanical Seal 851 (PS-851) —3/4″
Mechanical Seal 851 (PS-851) —3/4″
View ProductMechanical Seal 851 — Type 166 / T-16 (3/4″) | PS-851 Equivalent
Equal to industry standard 851 / PS-851.
Direct-fit Type 166 / T-16 single-spring seal for pool/spa and small-pump applications—built with a machined carbon/ceramic face set and Buna-N elastomers for reliable everyday service.At-a-glance specs: 3/4″ shaft • 1.375″ × 0.406″ cup seat • Machined carbon/ceramic faces • Buna-N elastomers
Why choose 851 (PS-851):
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T-16 footprint for quick, drop-in replacement
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Machined carbon face for smoother sealing vs. molded carbon
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Dependable materials for standard pool/spa chemistry
Upgrades / Variations (same footprint)
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201c — Basic (Buna)
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3868 — Premium + Viton
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201cv — Molded carbon
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201cvss— 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
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Mechanical Seal 957 (PS-957) — 5/8″
Mechanical Seal 957 (PS-957) — 5/8″
View ProductMechanical Seal 957 — Type 166 / T-16 (5/8″) | PS-957 Equivalent
Equal to industry standard 957 / PS-957.
Direct-fit Type 166 / T-16 single-spring seal for pool/spa and small-pump applications—built with a machined carbon/ceramic face set and Buna-N elastomers for reliable everyday service.At-a-glance specs: 5/8″ shaft • 1.187″ × 0.343″ cup seat • Machined carbon/ceramic faces • Buna-N elastomers
Why choose 957 (PS-957):
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T-16 footprint for fast, drop-in replacement
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Machined carbon face for smoother sealing vs. molded carbon
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Dependable materials for standard pool/spa chemistry
Upgrades / Variations (same footprint):
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100c — Basic
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3866 — Premium + Viton
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100cv — Molded carbon
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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
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Mechanical Seal 961 (PS-961) — 5/8″
Mechanical Seal 961 (PS-961) — 5/8″
View ProductMechanical Seal 961 — T-6A (5/8″) | PS-961 Equivalent
Equal to industry standard 961 / PS-961.
Direct-fit T-6A single-spring seal for pool/spa and small-pump applications—built with a machined carbon face for smoother sealing and longer life in everyday service.At-a-glance: 5/8″ shaft • 1.25″ × 0.406″ cup seat • Machined carbon/ceramic faces • Buna-N elastomers
Why choose 961 (PS-961)
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T-6A footprint for quick, drop-in replacement
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Machined carbon vs. molded carbon for improved surface finish and stability
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Dependable Buna-N for standard pool/spa chemistry
Upgrades / Variations (same footprint)
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1000 — Basic
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3865 — Premium + Viton
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1000cv— Molded carbon
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1000cvss — 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 for OEM numbers and Nameplate Data
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MG1 G4 Mechanical Seal – 25mm
MG1 G4 Mechanical Seal – 25mm
View ProductMG1 G4 Mechanical Seal 25mm – VIT/SiC/SiC (T-19 Equivalent) | Seat 38 × 7.5mm
Direct-fit aftermarket MG1 G4 25mm mechanical seal replacement seal built for demanding pump applications where extended wear life and chemical resistance matter. This version uses a Viton elastomer with Silicon Carbide / Silicon Carbide (SiC/SiC) sealing faces, making it an excellent choice for tough water conditions, higher heat, and abrasive service compared to standard carbon/ceramic combinations.
Specifications
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Seal Style: MG1 G4
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Shaft Size: 25mm
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Seat Size: 38mm × 7.5mm
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Elastomer: Viton (FKM)
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Face Materials: Silicon Carbide / Silicon Carbide
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Cross Reference: T-19, HD-8038, STG4VSC25
Cross references & alternative part numbers
This seal is also commonly referenced as:-
T-19 25mm mechanical seal
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HD-8038 seal
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STG4VSC25 seal
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MG1 25mm Viton SiC/SiC seal
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25mm mechanical seal with 38 × 7.5mm seat
Need help confirming fit?
If you’re matching a seal by size, confirm the shaft size (25mm) and the seat (38 × 7.5mm) before ordering. If you want, send us the pump model and a photo of the old seal/seat for verification. -
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Single Spring Mechanical Seal 3015 | PS-3015 Equivalent (G-Type / 2100)
Single Spring Mechanical Seal 3015 | PS-3015 Equivalent (G-Type / 2100)
View ProductSingle Spring Mechanical Seal 3015 | PS-3015 Equivalent (G-Type / 2100)
Direct-fit aftermarket 3015 / PS-3015 mechanical pump seal built in the G-Type / John Crane 2100 style—a compact, unitized, single-spring elastomer bellows seal design widely used across pump applications. Ideal for repairs where you need OEM-style fit and reliable sealing performance.
Key specs: • Shaft size: 1-3/8″ (1.375″) single spring seal • Seat: 2.000″ x 0.437″ • Rotary OD: 1.929″ • Working length: 1.024″
Material build: VIT / SIC / SIC — Viton elastomers; Silicon Carbide vs. Silicon Carbide faces
Excellent chemical/temperature resistance and wear durability.Please click “specifications” below for OEM numbers and Pump Nameplate Data
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.
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Single Spring Mechanical Seal 3020 | PS-3020 Equivalent (G-Type / 2100)
Single Spring Mechanical Seal 3020 | PS-3020 Equivalent (G-Type / 2100)
View ProductSingle Spring Mechanical Seal 3020 | PS-3020 Equivalent (G-Type / 2100)
Direct-fit aftermarket 3020 / PS-3020 mechanical pump seal built in the G-Type / John Crane 2100 style for reliable, leak-tight performance. This is a common single-spring seal used across industrial and HVAC/hydronic pump applications—match dimensions and OEM references before ordering.
Key specs: • Shaft size: 2-1/8″ (2.125″) single spring seal • Seat: 3.000″ x 0.562″ • Rotary OD: 2.717″ • Working length: 1.181″
Material build (standard)
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VIT / SIC / SIC — Viton elastomers; Silicon Carbide vs. Silicon Carbide faces
Excellent chemical/temperature resistance and wear durability.
Fitment
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O-ring seat design
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Listed as compatible with VSC-style pump assemblies
Please click “specifications” below for OEM numbers and Pump Nameplate Data
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.
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Single Spring Mechanical Seal 3021 / 3802 | PS-3021 ; PS-3802 Equivalent
Single Spring Mechanical Seal 3021 / 3802 | PS-3021 ; PS-3802 Equivalent
View ProductSingle Spring Mechanical Seal 3021 / 3802 | PS-3021 PS-3802 Equivalent
Direct-fit aftermarket replacement G-Type mechanical seal equal to industry standard 3021 / 3802 and PS-3021 / PS-3802. Built to the John Crane 2100-style design for reliable, leak-tight performance in demanding pump service.
Key specs: • Shaft size: 3.000″ single spring seal • Seat: 3.875″ × 0.625″ • Rotary OD: 3.898″ • Working length: 2.062″
Material build
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VIT / SIC / SIC — Viton elastomers; Silicon Carbide vs. Silicon Carbide faces
Excellent chemical/temperature resistance and wear durability.
Cross-references
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3021 / 3802, PS-3021 / PS-3802
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Industry standard G-Type / John Crane 2100
Have questions? Check out our Single Spring Seal Guide or call us anytime—we’re here to help.
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.
Please click “specifications” below for OEM numbers and Pump Nameplate Data
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Single Spring Mechanical Seal 3022 | PS-3022 Equivalent (G-Type / 2100)
Single Spring Mechanical Seal 3022 | PS-3022 Equivalent (G-Type / 2100)
View ProductSingle Spring Mechanical Seal 3022 | PS-3022 Equivalent (G-Type / 2100)
Direct-fit aftermarket G-Type mechanical seal equal to industry standard 3022 / PS-3022. Designed in the John Crane 2100-style configuration for reliable, leak-tight performance in common pump services.
Key specs: • Shaft size: 2-3/8″ (2.375″) single spring seal • Seat: 3.250″ x 0.562″ • Rotary OD: 3.150 • Working length: 1.299″
OEM reference
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OEM number: 81974941
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Brand: Flowserve Corporation
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Nameplate data: VCS Mechanical Seal
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.
Please click “specifications” below for OEM numbers and Pump Nameplate Data
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Single Spring Mechanical Seal 3170 | PS-3170 Equivalent
Single Spring Mechanical Seal 3170 | PS-3170 Equivalent
View ProductSingle Spring Mechanical Seal 3170 | PS-3170 Equivalent (G-Type / 2100)
Direct-fit aftermarket replacement mechanical seal 3170 / PS-3170 built in the G-Type / John Crane 2100 & 2106 style for reliable, leak-tight performance. This seal is a common solution for 2.000″ shaft pump repairs where a floating mating ring (Type G) configuration is required.
Key specs: • Shaft size: 2.000″ single spring seal • Seat: 2.750″ x 0.500″ • Rotary OD: 2.598″ • Working length: 1.500″
Material build (standard):
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VIT / SIC / SIC — Viton (FKM) elastomers; Silicon Carbide vs. Silicon Carbide faces
Excellent chemical/temperature resistance and wear durability.
Key Features:
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Upgraded design: Replaces the original carbon rotary face with a silicon carbide rotary face for enhanced durability and abrasion resistance.
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Includes Viton #129 O-ring for sleeve
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Seal type: T-25 L-shape floating seal
Cross Reference:
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OEM Number: P5001890
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Brand: Bell & Gossett (a Xylem brand)
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.
Please click “specifications” below for OEM numbers and Pump Nameplate Data
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