Thermoplastic or Elastomeric seats are inserted inside of a metallic holder (seat ring) to provide comfortable seating motion within a ball valve. The key options of the delicate-seated ball valve are The graphite packing rings are compressed and held in placement from the gland flange, that's bolted to your stem https://shop84938.wikimeglio.com/9787080/the_definitive_guide_to_butt_weld_pipe_fittings