What is the purpose of the raised pad on the hydrant elbows and tees?

The purpose of the raised pad (boss) on an HL Series No-Lead Bronze, SSHL 304 S.S. Hydrant Elbows and the HT Series No-Lead Bronze, SSHT 304 S.S. Hydrant Tees is to provide protection for the PE (Polyethylene) Pipe and the S.S. gear clamp bands.