Plate flat welding flange sealing surface: flat (FF), raised face (RF) production materials: stainless steel (Stainess Steel): 201,202,301,304,304L, 316,316L, 321, stainless steel flanges applicable standardization Industry HG20593-1997, GB GB / T9119 -2000, machine standard JB / T81-94 main dimensions and connecting dimensions reference plate flat welding flange (flange) is to connect two pipes, fittings or equipment attached to each one of the flange, the two flanges between the plates, plus flange gasket, bolted together to complete the connection. Some fittings and equipment already comes with flange, also belong to the flange connection. Flanged connections are important pipeline construction. Flange (Flange) also known as the flange or flange flange tube and pipe is interconnected parts, connected to the pipe end. There are holes on the flange, so that the two flange bolts abuts Inter flange lining gasket seal flange points threaded connection (wire connected) flange and welding flange. Pressure Flange (sae flange JBZQ 4187-97) flanged fittings (flanged pipe fittings) refers to the flange (flange or disk access) with The tubular member which may be cast from, can also be screwed or welded constitute elbow in the piping system, the piping is to change the direction of the elbow pipe. By angle points, 45 ° and 90 ° 180 ° three most commonly used, according to project needs in addition also includes other non-normal 60 ° angle bend. Elbow materials are cast iron, stainless steel, alloy steel, malleable iron, steel, nonferrous metals and plastics. Way connected with the pipe are: direct welding (the most common way) flange connection, hot melt connection, fused connection, threaded connections and socket type connections. According to the production process can be divided into: welding elbow, pressing elbow, push the system elbow, casting elbow. Other names: 90 degree elbow, right-angle bends and so on. 1. Material division: Carbon Steel: ASTM / ASME A234 WPB, WPC alloys: ASTM / ASME A234 WP 1-WP 12-WP 11-WP 22-WP 5-WP 91-WP911,15Mo3 15CrMoV, 35CrMoV stainless steel: ASTM / ASME A403 WP 304-304L-304H-304LN-304N ASTM / ASME A403 WP 316-316L-316H-316LN-316N-316Ti ASTM / ASME A403 WP 321-321H ASTM / ASME A403 WP 347-347H cold steel: ASTM / ASME A402 WPL3-WPL 6 High performance steel: ASTM / ASME A860 WPHY 42-46-52-60-65-70 steel, alloy steel, stainless steel, copper, aluminum, plastic, argon Ge Lek, PVC, PPR, RFPP ( reinforced polypropylene). 2. production methods can be divided into push the system, pressing, forging, casting and so on. 3. manufacturing standards can be divided into GB, electricity standard, ship standard, technology standard, water standard, American standard, German standard, Japanese standard, the Russian standard and so on. 4. It's the radius of curvature of points: can be divided into long radius elbows and short radius elbows. Long radius elbow refers to its radius of curvature is equal to 1.5 times the outer diameter of the tube, i.e., R = 1.5D; short radius elbow refers to its radius of curvature is equal to the pipe diameter, i.e. R = 1.0D. (D is the bend diameter, R is the radius of curvature). 5. In terms of pressure levels to points: Approximately seventeen species, and the US standard pipe is the same, there are: Sch5s, Sch10s, Sch10, Sch20, Sch30, Sch40s, STD, Sch40, Sch60, Sch80s, XS; Sch80, SCH100, Sch120, Sch140, Sch160, XXS; one of the most commonly used two kinds of STD and XS. 6. The use of different shapes can be divided into: grooved elbow, elbow card sets, double bearing elbows, flanges elbow, reducing elbow, elbow seat stay, both inside and outside the tooth elbow, pressing elbow push the system elbow, socket elbow, butt elbow, elbows, etc. within