Type 604 Metal Bellows Seals | Pump Seals | John Crane

Type 604

High-temperature, Stationary Edge-welded Metal Bellows Seal

The Type 604 is a high-temperature, general-purpose, stationary edge-welded metal bellows assembly for applications to 425C/800F. Available in either AM350 or Alloy 718, its high-strength design provides maximum reliability. The stationary bellows design accommodates high shaft-to-seal-chamber misalignment. Unlike rotating seals that must flex on every revolution to accommodate shaft-to-seal-chamber misalignment, the stationary Type 604 adapts to this condition by flexing only once during installation. This reduces seal movement, resulting in increased seal life. Typical applications include hot hydrocarbons, aqueous solutions, aromatic fractionation products, crude oil fractionation products and heat transfer fluids.



  • California Residents: PROPOSITION 65 WARNING
  • John Crane edge-welded metal bellows in Alloy 718 or optional heat-treated AM350 SS.
  • DOUBLE-PLY for high-pressure applications.
  • High-temperature to 425C/800F.
  • API-682 qualified.
  • Available in dual and single cartridge arrangements.
  • Available with secondary containment.
  • Elastomer-free design with flexible carbon graphite secondary seals.
  • Seal face is available with premium grade carbon, silicon carbide or tungsten carbide.

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