90° 7d A234 Wp11 273x25mm Steel Pipe Bend CE

90° 7D A234 WP11 273X25mm Alloy steel pipe bend fitting hot-bending bend BE

Generally, small-diameter bends can be obtained by cold bending; Large diameter pipes need hot bending.

Medium frequency bends are now widely used in pipe prefabrication in engineering fields such as electric power, petroleum, chemical industry, navigation and nuclear industry. However, the wave folds of medium frequency bends are significantly larger at the arc starting point, especially when the tortuous radius is less than 3Do (do is the outer diameter of the pipe), the inner arc wave folds are larger, which seriously affects the appearance quality of products, This is a problem that domestic pipe benders have been unable to deal with and urgently need to deal with for decades. The medium frequency pipe bender adopts the power supply with straight external characteristics, and the positive polarity (welding wire connected to negative electrode) is selected when DC. The medium frequency pipe bender is generally suitable for the welding of thin plates below 6mm, with the characteristics of beautiful weld formation and small welding deformation? The maintenance gas is with purity of 99.99%. When the welding current is 5050a, the flow is 80L / min; when the current is 50250a, the flow is 25L / min. For the length of welding arc, 24mm is preferred when welding ordinary steel, and 3mm is preferred when welding stainless steel. If it is too long, the maintenance function is not good. In order to prevent the appearance of welding pores, the welding part of medium frequency elbow must be cleaned if there is rust and oil stain. The length of the tungsten electrode from the gas nozzle is preferably 45mm, 23mm in areas with poor shielding such as fillet welding, 56mm in areas with deep groove, and the interval from the nozzle to the operation generally does not exceed 5mm During butt backing of intermediate frequency bend, gas maintenance is also required on the reverse side of the bottom weld bead to prevent oxidation Windproof and ventilation. In windy areas, be sure to adopt the method of blocking the net, while indoors, you should adopt appropriate ventilation methods. In order to maintain the welding pool well and facilitate the welding operation, the angle between the center line of tungsten electrode and the workpiece at the welding position shall generally be 80-85 °, and the included angle between filler wire and the surface of the workpiece shall be as small as possible, generally about 0 °.

Material of pipe Bends