采用内衬覆膜树脂砂的热型法，生产内径为１２００ｍｍ的大型离心球墨铸铁管。对离心球墨铸铁管的化学成分和内在质量进行控制，并与衬覆膜砂的工艺相配合进行了生产试验，使离心球墨铸铁管的力学性能和尺寸精度均达到ＩＳＯ２５３１－９１（Ｅ）的标准，现已批量生产 Lined with resin coated sand thermal method, the production diameter  1200mm large centrifugal ductile iron pipe. The chemical composition and internal quality of centrifugal ductile iron pipe are controlled, and the production test is carried out in coordination with the process of coated membrane sand so that the mechanical properties and dimensional accuracy of centrifugal ductile iron pipe meet the standards of ISO2531-91 (E) , Is now in volume production