Chesterton 491 Rotary Internal Single Mechanical Seal

16 to 110mm shaft sizes, designed in accordance with EN 12756 to fit the short length installation requirements.

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Product Manual

Effective April 15th, 2025 Chesterton has added a 3% surcharge for all of their products. The surcharge will appear as a separate line item on the order.

Highlights...

Features

  • 16 to 110mm shaft sizes
  • -67 to 570°F (-55 to 300°C) operating temperature
  • 150psig (10barg) pressure rating
  • Face Materials:
    • Carbon Graphite/Ceramic
    • Carbon Graphite/Silicon Carbide
    • Silicon Carbide/Silicon Carbide
  • Elastomers
    • Ethylene Propylene (EP)
    • Fluorocarbon (FKM)
  • Up to 4000 FPM operating speed
  • 316 Stainless Steel / EN 1.4401 metal parts
  • Alloy C-276/EN 2.4819 springs
  • ISO-3069-S, NSF61, ATEX

The Chesterton 491 Rotary Internal Single Mechanical Seal is designed not to damage or fret the equipment shaft/sleeve because the dynamic O-Ring is positioned on a replaceable component surface. This balanced, high-pressure monolithic seal design provides a performance upgrade to standard, original equipment component seals. The seal can be easily rebuilt in the field using low-cost rebuild kits.