Butterfly valve flange, also called butterfly special flange or clamp butterfly valve flange and clamp special flange, is a flange that matches the clamp butterfly valve. The main difference between the special clamp butterfly valve flange and the ordinary flange piece is the inner diameter of the flange, the inner diameter of the butterfly valve flange is just a groove that matches the nominal diameter of the butterfly valve required, this groove can be welded on the connected steel pipe, ensuring the sealing effect of the clamp butterfly valve, if the ordinary flat welding flange is used, the sealing effect of the butterfly valve It is not guaranted. In addition, the outer diameter, thickness, center distance and bolt hole of the special flange for clamp butterfly valve are the same, and the bolt used is a double-ended bolt. Because the processing of the inner groove of the special flange for butterfly valve is one more process than the flat welding flange, the price is slightly higher than that of the ordinary flat welding flange.
The commonly used materials of butterfly valve flange can be divided into carbon steel and stainless steel: carbon steel: (20#, A3, Q235, Q235A, Q235B, 20G, 16Mn, Q345, Q345R, ASTM A234WPB, 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 implementation standards for butterfly valve flanges:
American standard flange: ASME B16.5, ASME B16.47
National flange standards: GB/T9112-2010, GB/T9119-2010, GB/T9116-2010, GB/T9115-2010
Flange Chemical Industry Department Standards: HG/T20592-2009, HG/T20615-2009, HG5010-52 ~ HG5028-58, HGJ44-91 ~ HGJ 65-91, HG20592-97
