... 3,QT700/2 Grey iron:HT150,HT200,HT250,D400,E600,F9 Ductile iron manhole cover 1)ductile iron ... /2 Grey iron:HT150,HT200,HT250,D400,E600,F9002)Loading weight of pressure:A15,B125,C250, ... D400,E600,F9003)Certification of quality:ISO9001:20004)Main market ... 3) Product series include Class B125, C250, D400, E600, F900 meeting the relevant EN124, BVQI and Australian standards ...