... 3.Max pressure:A15,B125,C250,D400 4.Certification:ISO90 Cast iron Manhole CoverFeature:1 environmental protection with non-toxicity raw ... Our company specializes in the production of ductile iron manhole covers, rain olivier, W-type tube, the variety specification is complete, two ... hospitals, factories, community, the station, the airport and so on all sorts of public and urban roads and the fast lane ...