How is PTFE used below the pipe saddle?

The PTFE is generally used as a slide plate either affixed to the supporting steel or the bottom of the pipe saddle. This PTFE component acts to provide a low coefficient of friction between the saddle and the supporting steel.

Stainless Steel Slide Plates Affixed to Bottom of Pipe Saddle
Stainless Steel Slide Plates Affixed to Bottom of Pipe Saddle
Top