The general types of flanges are: plate flat welding flange, neck flat welding flange, neck butt welding flange, socket welding flange, thread flange, flange cover, neck butt weld ring loose flange , flat welding ring loose flange, ring groove flange, large diameter flat flange, large diameter high neck flange, eight-shaped blind plate, plate flat welding flange, butt welding ring loose flange; Pipe flanges can be divided into five basic types according to the way of connection with pipes: flat welding flanges, butt welding flanges, threaded flanges, socket welding flanges, and loose flanges. There are many types of sealing surfaces for flanges. Commonly used are convex (RF), concave (FM), concave and convex (MFM), grooved (TG), full-planar (FF), and ring-connected (RJ). Carbon steel flat welding flange: suitable for carbon steel pipe connection with nominal pressure not exceeding 2.5MPa. The sealing surface of flat welding flange can be made into three types: smooth, concave and convex and grooved. The smooth flat welding flange has the largest application amount, and is mostly used in the case where the medium condition is relatively mild, such as low pressure non-purified compressed air and low pressure circulating water, and its advantage is that the price is relatively cheap; Butt-welded steel flange: used for the butt welding of flange and pipe, its structure is reasonable, the strength and rigidity are large, it can withstand high temperature and high pressure and repeated bending and temperature fluctuation, the sealing property can be *, the nominal pressure is 0.25 ~ 2.5MPa The butt weld flange has a concave and convex sealing surface. Socket welding flange: commonly used in pipelines with PN≤10.0MPa and DN≤40; Loose flange: loose flange is commonly known as loop flange, split ring loop flange, flanged loop flange and butt seam flange, often used for medium temperature and pressure is not high and medium corrosive Strong situation. When the medium is highly corrosive, the part of the flange that contacts the medium (the cuffed short section) is a corrosion-resistant high-grade material such as stainless steel, while the outside is clamped with a flanged ring of a low-grade material such as carbon steel. To achieve a seal; Integral flange: It is often the integration of flanges with equipment, pipes, fittings, valves, etc. This type is commonly used on equipment and valves. Commonly used standards: GB: GB/T9112-2000 (GB9113 1-2000~GB9123?4-2000) American standard: ANSI B16.5 Class150, 300, 600, 900, 1500 (WN, SO, BL, TH, LJ, SW) Japanese standard: JIS 5K, 10K, 16K, 20K (PL, SO, BL, WN, TH , SW) German standard: DIN2573, 2572, 2631, 2576, 2632, 2633, 2543, 2634, 2545 (PL, SO, WN, BL, TH) Ministry of Chemical Industry Standard: HG5010-52～HG5028-58, HGJ44-91～HGJ65-91, HG20592-97 Series, HG20615-97 Series Ministry of Machinery Standard: JB81-59~JB86-59, JB/T79-94~JB/T86-94, JB/T74-1994 Pressure vessel standard: JB1157-82~JB1160-82, JB4700-2000~JB4707-2000 Cooked Starch Lobe Pump,Rotary Lobe Pump,Defoaming Agent Transfer Pump,Sulfoacid Transfer Pump NINGBO DURREX PUMPS CO.,LTD , https://www.durrexlobepump.com