hubbed flange Slip On flange welded neck flange, hubbed flange Tread flange,Blind flange socket welding flange hubbed flange Material : 1. Carbon Steel :ASTM A105,20, Q235, 16Mn, ASTM ... : 1.Threaded Th 2.weld Neck WN 3. Slip-On SO 4. plate PL 5. sock welded SW 6. Pipe Joint ... ), DIN2573,2572,2631,2576,2632,2633,2543,2634,2545(PL,SO,WN,BL,TH)UNI standard.GB standard. JB standard. HG ...