blind flange class 150/600/900 1.Size:4'' * 150lbs 2.Material: A105 3.Standard:ANSI B16.5 ... 4.Qualification;API,ISO,CE blind flange class 150/600/900size 1 ... 1500Lbs, 2500Lbs,Etc /PN6,PN10,PN16,PN20,PN25,PN40/ Class A, B, C, D, EstandardASME B16.5, ... National Petroleum Corporation.We are also qualified the standard material supplier of China National Offshore Oil ...