Seal combination comprising a ring made of wear-resistance material (mostly filled PTFE) with a smooth or recessed edge sliding surface that is energised by an O-ring behind it (Figure G 27).
The somewhat awkward name comes from the ISO documentation. The terms occasionally used, such as sliding ring or seal-edge ring may be easier, but they do not address the key aspect.
Figure G 27: Elastomer/energised plastic faced seal