Note on the installation of buttwelding elbow
Points to note about the installation of the weld elbow:
1.Before the welding elbow is installed, the pipe joints should be measured one by one, numbered, and the pipe joints with the smallest difference in pipe diameter should be selected. When splicing the pipeline in the ground alignment, the 14CM*14CM sleeper should be used to flatten the pipe. It is not advisable to use iron steel pipe, and the pipe rolling should be minimized to avoid damage to the outer corrosion of the pipe.
2.Check the inner and outer anti-corrosion layers of the pipe joint before the pipe is installed. When the pipe section constitutes the pipe section, the length and pitch of the pipe section shall be determined according to the pipe diameter, wall thickness, material type of the outer anti-corrosion layer and the method of pipe laying. The sling should be made of soft material such as rubber pipe rope or strong rope to avoid the outer coating of the steel pipe. The distance from the starting point of the elbow to the interface is not less than the pipe diameter and shall not be less than 100MM. The welding rod used for pipe joint welding shall comply with the design and specifications.
3.Clean the dirt inside the pipe, and clean the edges of the pipe mouth and the sides of the welding joint to expose the metal luster and make the groove. The opposite ends of the two pipe ends are set at the center of the pipe, and three places are spot welded along the circumferential direction of the pipe (the length of the electric weld is about 4 mm, the height is about 5 mm), and the two pipes are fixed. The 2-3MM layer is welded to fill the circumference of the pipe. The weld elbow weld surface is smooth without cracks, pores, blisters and other defects.
4. When the ambient temperature is lower than 0 °C, it must be covered with asbestos after the welding is completed. The slag is removed after the welding is completed. The straightness should be checked after the pipe is in the mouth and measured at 200 mm from the center of the interface. The allowable deviation is 1 MM/M.