FEP/PFA Encapsulated O-ring Part 2
tip is about the characteristics the inner elastomer core brings
to the o-ring)
in mind that just as the outer jacket of FEP or PFA in the FEP/PFA
encapsulated o-ring brings certain advantages to the o-ring, the
inner elastomer core also brings its own desirable characteristics.
That doubles the advantages you can get from this one o-ring.
at PSP we find that most of our customers prefer a Viton®
core. Because of the low compression set of Viton®, it is
a good fit for most applications. If the application requires
extremely high or low temperatures then another elastomer needs
to be chosen.
encapsulated o-ring with silicone as the core works very well
for a very low temperature applications. If low loading is also
a requirement, then a hollow core can be used, it compresses easier
than a solid silicone core.
spite of the fact that FEP/PFA encapsulated o-rings offer so many advantages,
there are times when you would not want to use them.
FEP and PFA do not wear well in abrasive materials whether
they are liquid, powder or a slurry. The wall of the jacket is
thin and simply will not stand up to any kind of abrasive materials.
FEP and PFA do not stand up well in a dynamic environment
even in situations with low speed and excellent finishes on the
surface of the mating parts.
If you try to squeeze the encapsulated o-ring into a
bore it can be severely damaged because the jacket will kink.
Just as FEP and PFA cannot be compressed, it also will not survive
extreme stretching. They will crack and the elastomer core of Viton®
or silicone may also break.
call us if you need help in choosing a FEP/PFA encapsulated o-ring
for your application. Our engineers are happy to talk about all
the details of your application so you can make a wise choice.