Blind flange is also known as blind flange or blind flange, flange cover, BL blind, the center of the blind flange is solid, surrounded by bolt holes, the appearance is like an iron cover, so it is also called flange cover. The blind flange is used to lock the end of the pipe, which can facilitate the removal of debris from the pipe during maintenance. As far as the plugging effect is concerned, it has the same effect as the head and cap, but there is no way to disassemble the head and cap after welding, and the flange blind plate is fixed with bolts, which is convenient to disassemble.
The blind flange can be divided into carbon steel according to the production material: (20#, A3, Q235, Q235A, Q235B, 20G, 16Mn, Q345, Q345R, ASTM A105, etc.); Stainless steel: (304, 304L, 316, 316L, S30408, S30403, S31608, S31603, SUS304, ASTM A403, TP321, TP317L, 347, 0Cr18Ni9, 00Cr19Ni10, , 1Cr18Ni9Ti, 06Cr17Ni12Mo2 , 022Cr17Ni12Mo2, etc.);
Commonly used blind flange sealing surface shape code: RF protruding, FM concave, M convex, T mortise, G groove, FF full plane, RJ ring connection surface
Commonly used implementation standards for blind flanges: China's current flange standards are divided into two systems, namely PN series (European system) and Class series (American system). The pressure marking specified in this standard is divided into PN marking and class marking. The PN marking has 12 pressure levels, namely: PN2.5; PN6; PN10; PN16; PN25; PN40; PN63; PN100; PN160; PN250; PN320; PN400. Class markings have 6 pressure levels: Class 150; Class 300; Class 600; Class 900; Class1500; Class 2500. Executive standards include GB series (national standard), JB series (mechanical department), HG series (chemical department), ASME B16.5 (American standard)
American standard standards: ASME B16.5, ASME B16.47
National standards: GB/T9112-2010, GB/T9119-2010, GB/T9116-2010, GB/T9115-2010
Chemical standards: HG/T20592-2009, HG/T20615-2009, HG5010-52 ~ HG5028-58, HGJ44-91 ~ HGJ65-91, HG 20592-97
