Pall ring packing has many advantages ,such as:larger flux,smaller resistance,smaller Separation efficiency and small operating flexibility. ModelSpecific Surface Area m2/m3Void Ratio %Packing Efficiency Piece/m3Specific Gravity Kg/m3Material25×2520728453500103±5%plastic38×381281701360077±5%plastic50×50102131636073±5%plastic76×769194210065±5%plastic