1, Products: WN, SO , BL , TH, LJ , SW 2, Painted: black, varnish, antirust oil 3, Qualification: ISO9001, API, CE, I ANSI B16.5 Class150, 300, 600, 900, 1500II JIS 5K, 10K, 16K, 20K (PL, SO, BL) III DIN2573, 2572, 2631, 2576, 2632, 2633, 2543, 2634,2545(PL,SO,WN,BL,TH) IV HG20592-97(HG20593-97-HG20614-97) V HG20615-97(HG20616-97-HG20635-97) VI HG5010-52-HG5028-58,HGJ44-91-HGJ65-91 VII JB81-59- ...