Standard roller chain was used as drive chain for collector mechanism in the past, bur HB type bushed stainless steel chain is replacing roller chain popularly due to higher wear resistance. Pitch, bushing diameter and width of internal links are same as roller chain. HBD is double pitch version.
HB78 and HSS4124 stainless steel bushed drive chain are appreciated by many wastewater plants due to light weight, high tensile strength and corrosion resistance as well as high wear resistance.