Resistance of sealing materials

Zero maintenance or long service intervals – these are product properties that take top priority with JAKO when it comes to the selection of durable and suitable materials.

This not only applies to the metals used, but also to the sealants (e.g. in form of 0 rings, spacing washers and diaphragms or surface coatings). Mostly the following elastomer compounds, i.e. form-stable but elastically deformable plastics that get their specific properties (e.g. chemical resistance) through an admixture of additives, are used.

  • NBR – acrylonitrile butadiene rubber
  • FPM – fluoropolymer rubber
  • EPDM – ethylene propylene dien rubber
  • FFPM -.(perfluorinated rubber (optional)
  • CR – chloroprene rubber (optional)
  • PTFE – polytetrafluoroethylene packaging (optional, widely used commercial name: Teflon)

These sealants are used:

  • as housing sealing (e.g. bayonet ring housing) and for the sealing of connectors
  • in screw couplings and process connections
  • as separating and upstream diaphragm e.g. in diaphragm pressure gauges or chemical seals
  • as surface coating

The decision for the right material depends on the following parameters:

  • measuring medium
  • operating pressure
  • measuring medium temperature
  • other application requirements such as silicone free, oil and grease free

Table 1: Resistance of elastomers in connection with customary refrigerants

Refrigerant NBR FKM EPDM FFKM CR PTFE
 R 11 2 1 0 1 0 2
 R 12 1 1 1 1 2 2
 R 12 B1 0 0 0 0 1 2
 R 13 2 1 2 1 2 2
 R 13 B1 2 1 2 1 2 2
 R 14 2 1 2 1 2 2
 R 21 0 0 0 0 1 2
 R 22 0 0 2 0 2 2
 R 31 0 0 2 0 2 2
 R 112 1 1 0 1 1 2
 R 113 2 1 0 1 2 2
 R 114 2 1 2 1 2 2
 R 114 B2 1 1 0 1 1 2
 R 115 2 1 2 1 2 2
 R 124 0 0 1 0 1 2
 R 134 a 1 0 1 0 1 2
 R 142 b 2 0 1 0 2 2
 R 152 a 2 0 2 0 2 2
 R 218 2 2 2 2 2 2
 R 290 1 1   1    
 R 401 a         1  
 R 401 b         1  
 R 402 a         1  
 R 403 b         1  
 R 404 b 1 0 1 0 1 2
 R 407 a 1       1  
 R 407 b         1  
 R 407 c   0 1 0 1 2
 R 408 a         1  
 R 409 a         1  
 R 410 a 1       2  
 R 413 a 1          
 R 502 1 1 2 1 2 2
 R 507 1       1  
 R 600 a 1 1     1  
 R 717 (liquid) 1 0 2 0 2 2
 R 717 (gaseous) 2 0 2 0 2 2
 R 717 (hot and gaseous) 0 0 1 0 1 2