Type 20 and 20R PTFE Bellows Seals | Pump Seals | John Crane

Type 20/20R

Chemically Inert Materials In All Areas and On All Surfaces

Types 20 and 20R shaft seals feature chemically inert materials in all areas and on all surfaces in contact with the liquid being sealed. Metallic components, springs and clamp ring are located outside the pump seal chamber, isolated from the process liquid.

For use with extremely corrosive chemicals, including concentrated acids and salts, strong oxidizing and reducing agents, and chemically active organic compounds commonly used on PTFE filled pumps.

The entire seal assembly and component parts employ mechanical drive to prevent slippage on the shaft or sleeve. Seal assembly is outside mounted and internally pressurized.



  • California Residents: PROPOSITION 65 WARNING
  • Maximum corrosion resistance.
  • Eliminates possibility of seal face misalignment.
  • Compensates for shaft runout to promote low maintenance, long-life operation.
  • Independent spring assembly
  • Replaceable primary ring (Type 20R) provides uniform face loading characteristics.
  • Easy removal and replacement of sealing member most subject to wear.

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