1.Type:steel manhole cover 2.Material:SUS304,316L,etc. 3.Size:300mm-500mm 4.Max pressure:0.4MPa 5.HACCP,ISO9001:2000,QS-9000 Food grade steel manhole cover Material:SUS304,SUS316L Size:Φ300-Φ500 Internal surface:Ra 0.8μm—0.5μm Outside surface:mirror polishing Media:gas,water,oil,etc. Gasket:EPDM,NBR,Silicon,FPM Food grade steel manhole cover