Seals

Ball valve seals made of PTFE, POM or PEEK are used to guarantee a sealing function with minimum friction.

Material properties:

POM is used when high dimensional stability is required.
PTFE is used for high temperatures, chemical resistance and food grade compliance.   
PEEK is used for high pressure stability and high temperatures.

PTFE ball valve sealing rings are suitable for temperatures up to 220°C, have a low breakaway torque and are resistant to chemicals.
breakaway torque and are resistant to chemicals.

Ball valve sealing rings made of PEEK, on the other hand, are used when higher pressure resistances are
are required.