Cautions for Installation and Use of Straight Seam Steel Pipes

Straight seam steel pipe is widely used in petroleum, metallurgy, construction, coal mine, port, machinery and other industries. During the installation and use of straight seam steel pipe, there are strict technical requirements, which should be carried out according to the actual situation and operation specifications to ensure the safety and quality of straight seam steel pipe. During normal use, the following points should be noted:


1. Construction preparation before installation of straight seam steel pipe
The pipe trench shall be excavated according to the requirements of the drawings. After the completion of the construction of the pipeline well, all kinds of straight seam steel pipes required have arrived with good quality and passed the inspection. The required construction tools, including electric welding machine, cutting machine, electric hammer, polishing machine, etc., are ready, and installation can only be started after a series of preparations.


2. Installation process of straight seam steel pipe
Position the pipe according to the drawing design, prefabricate the pipe support according to the site conditions, cut the materials according to the design and site, polish the bevel angle with a polishing machine, and then weld. During welding, the strip shall be sent to the pipe welding unit and rolled by multiple rollers, then the strip shall be rolled gradually to form a circular tube blank with open gap, and the reduction of the extrusion roller shall be adjusted to control the weld gap at 1-3mm, and both ends of the weld shall be flush. If the gap is too large, the proximity effect will be reduced, the eddy current heat will be insufficient, and the welding between grains will become poor, resulting in fusion or fracture. If the gap is too small, the proximity effect will increase, and the welding heat will be too large, which will cause the weld to burn out; otherwise, the weld will form a deep pit after extrusion and rolling, which will affect the surface quality of the weld.


3. Installation quality inspection of straight seam steel pipe
(1) the welded pipe shall not be welded at the weld and the weld shall not be welded at the elbow.
(2) the deviation of vertical installation pipe per meter shall be less than 3mm, and that of horizontal installation pipe shall be less than 1mm.
(3) the surface quality of the straight welded pipe shall be flat, and no folding, cracking, layering, overlapping and other defects are allowed. Minor defects (such as scratches, scratches, misaligned welds, burns and scars) on the surface of straight seam pipes shall not exceed the negative deviation of the wall thickness.