Type 604 John crane
Type 604 John crane

Features mechanical seal type 604

  • 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.

Recommended Applications type 604

  • Process pumps

About Mechanical seal type 604

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.

Design Features mechanical seal type 604

  • Edge-welded metal bellows
  • Elastomer-free design
  • Standard components
  • Available in single or dual cartridge arrangements
  • Available with a secondary containment seal
  • The Type 604 and Type 609 meet API 682 requirements
  • Available with double-ply bellows

Material mechanical seal type 604

  • Bellows: Alloy 718 (UNS N07718)
  • Insert/Primary Ring: Premium Carbon Grade/Silicon Carbide/Tungsten Carbide
  • Static Seals: Flexible Graphite
  • Shell/Primary Ring Adaptor: Alloy 42 (UNS K94100)
  • Adaptor: Alloy 625 (UNS N06625)

Operating range mechanical seal type 604


Temperature Limits

-100°F to 800°F/-75°C to 425°C with flexible graphite static packing


Pressure Limits

Vacuum to 360 psi(g)/25 bar(g)


DOUBLE-PLY: Vacuum to1000 psi(g)/69 bar(g)


(See Basic Pressure Ratings curve on Product Specification sheet.)


Speed Limits


Product Description type 604

Type 604 – High-temperature general-purpose stationary bellows assembly capable of handling high shaft speed applications and high shaft-to-seal chamber misalignment.