This document specifies the terms and definitions, classification and structural form, basic requirements, technical requirements, test methods, inspection rules, marking, packaging, transportation and storage of ductile iron composite resin inspection manhole covers for the petrochemical industry (hereinafter referred to as "manhole covers") and quality commitment. This document is applicable to ductile iron composite resin inspection manhole covers with a net opening of not more than 1000 mm used on road surfaces in refineries, oil depots, chemical plants and gas stations in the petrochemical industry.
T/ZZB 2594-2021 history
2021T/ZZB 2594-2021 Spheroidal graphite cast iron composite resin manhole cover for petrochemical industry