Type 680 John crane
Type 680 John crane

Features mechanical seal type 680

  • California Residents: PROPOSITION 65 WARNING
  • Static secondary seal available in single or dual arrangements, shaft-mounted or in a cartridge
  • Manufactured with a 45-degree tilt edge at the bellows’ inside diameter to disperse stresses and maximize operating life.
  • Superior nesting ripple plate shape with a three-sweep radius; this plate design allows the bellows device to be flexed repeatedly without the metal being stressed beyond its endurance limit.

Features mechanical seal type 680

  • Self-cleaning design — rotating bellows throw off suspended particles that clog spring-type seals. This self-cleaning action eliminates the need for external flushing, filters or cyclone separators and their associated costs.
  • World-class bellows manufacture — our bellows production facility has an outstanding manufacturing process with state-of-the-art stamping, welding and testing technology.
  • The bellows incorporate all of the design features resulting from key engineering competencies, such as metallic thin shell methodology, tribology and fluid sealing technology, and thin film/fluid mechanics

About Mechanical seal type 680

The Type 680 is the ideal seal for general-purpose applications. Its rotating Alloy-20 bellows provide corrosion resistance in a broad range of corrosive media. Its cost-effective design, combined with a reliable performance history, has made the Type 680 a standard for low-temperature applications found in the chemical, water and wastewater, pulp and paper, and utility industries. The seal is available with hard faces for abrasive applications and a wide range of elastomers to cover a broad range of applications.

Design Features mechanical seal type 680

  • Edge-welded metal bellows
  • Static secondary seal
  • Standard components
  • Available in single or dual arrangements, shaft-mounted or in a cartridge
  • The Type 670 meets API 682 requirements

Material mechanical seal type 680

  • Bellows: Alloy 20 (UNS N08020)
  • End-fittings: Alloy 20
  • Insert/primary ring: Premium carbon grade tungsten carbide, silicon carbide
  • Static seals: Fluorocarbon, EPR, PTFe-encapsulated fluorocarbon, nitrile, perfluoroelastomer

Operating range mechanical seal type 680

Standard Materials

Carbon face: To 200C/400F


Tungsten Carbide or Silicon Carbide face: 150C/300F


Pressure Limits

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


Speed Limits



Product Description type 680

All-alloy 20 low-temperature high-performance seal for use on a broad range of corrosive media.

Recommended Applications type 680

  • Process pumps
  • Other compressors
  • Other rotating equipment