John Crane Type 21
The Type 21 is an all purpose seal which rotates with the shaft against a stationary mating face. The Type 21 features mechanically crimped components eliminating the use of adhesives. We have many sizes and material configurations for engineers to choose from.


John Crane Type 21
John Crane Type 21
John Crane Type 21
Materials configuration:
  • Stationary Ring (Alumina 99%/Alumina 99.5%/SiC/SSiC/TC)
  • Rotary Ring (Carbon/SiC/SSiC/TC)
  • Secondary Seal (NBR/EPDM/Viton)
  • Spring and Punched Parts (SS304/SS316)
Working conditions:
  • Mediums: Water, oil, and chemical mediums with weak corrosion
  • Temperature: -20°C~150°C
  • Pressure: ≤0.8MPa
  • Speed: ≤ 10 m/Sec