... ,welded pipe and so on1 seamless steel pipe standard:GB/t8162-2008,GB/T8163-2008,GB3087-2008,GB5310-2008ASTM,API and so on Grade:203 ... ,1Cr5M and so on 2 stainless steel pipe standard:GB/t8162-2008,GB/T8163-2008,GB3087-2008,GB5310-2008ASTM,API and so on Grdae:201 ...