... 2.Material: SS304/SS316L 3.Certificate:ISO9001:2000 (sanitary manhole cover, manway cover) Export to North America and Europ market since 1996, ... the tanks or vessels can be locked up.YAC:arc manhole cover,which can sustain a Max.Static pressure of 2bar(under ... for big vessels with lagging material.YAC:flat manhole cover,lower bracket.YAC:flat manhole over,,higher bracket,suitable for big vessels with ...