... Max pressure:A15,B125,C250,D400 4.Certification:ISO90 Cast iron Manhole CoverFeature:1 environmental protection with non-toxicity ... durable .Our company specializes in the production of ductile iron manhole covers, rain olivier, W-type tube, the variety ... we would be told to classification shading. MaterialQT500-7 cast ironMOQ1tonsUseUsed in motor lane, municipal pipeline, communication, power supply ...