国际首创三层卷焊钢管内蒙古呼和浩特精密制管厂与燕山大学轧机研究所焊管科研组合作，采用国产原料，在国产设备上制成的三层卷焊钢管，经国际管材协会联机检索证明无此类产品，现已于１９９４年１２月２日通过了由内蒙古科委邀请国内焊管知名专家组织的新产品鉴定会（北... International first three-volume welded steel pipe Hohhot, Inner Mongolia Precision Pipe Factory and Yanshan University Mill Research Institute of rolling mills, the use of domestic raw materials, made in China-made three-tier welded steel pipe, the International Pipe Association online search to prove no such Products, is now on December 2, 1994 adopted by the Inner Mongolia Science and Technology Commission invited domestic well-known experts in the organization of new product identification (North ...