Pre-bending and sizing are the main steps within the spiral tube forming process. The key purpose of pre-bending is to solve the rebound problem of the tube blank, because the size of the rebound directly affects the intrinsic quality of the steel tube; the primary reason for the sizing is to have a better diameter of the tube, as the diameter control is the main quality index of the steel tube. The right match between pre-bending and sizing is required to obtain HDPE pipe fittings.
The following is a short discussion on the formation process and characteristics of submerged arc welding of galvanized spiral steel pipes with 630*3 ribs. The principle of submerged arc welding: Submerged arc welding is the use of arc thermal energy welding, and manual welding rod arc welding is different: the submerged arc welding of the welding wire is exposed, there is not any coating, submerged arc welding is indeed pre-paved welding flux to become welded The submerged arc welding wire extends in to the flux, as well as the arc is formed underneath the flux. The development procedure of the submerged arc welding is such the welding wire is in touch with the workpiece.
Right after the start button is pressed, the welding wire as well as the workpiece are energized, and also the welding wire is returned. Withdrawing, the arc ignites, the welding carriage advances, the welding wire is continuously conveyed downwards, the arc is maintained to shed underneath the flux layer, and the welding pool is formed underneath the arc. Across the arc, the flux melts to make a cavity. The cavity and also the pool still advance, and the metal behind the pool solidifies to make a continuous weld. This process is carried out beneath the flux, therefore we can’t view it using the human eye alone. It may be seen with X-ray photography.
Since the spiral steel pipe adopts the welding technology of submerged arc automatic welding, besides this kind of high production efficiency; the development auxiliary time is less, enough time for changing the welding rod is saved; the welding conditions are neat and no spatter, and the cleaning time is saved; the standard of the welding seam is high. Additionally, it provides the necessary conditions for that delivery of the spiral welded pipe plant, in order that the production time of the larger spiral steel pipe is guaranteed, so it is still commonly used.
1. Pressure-bearing fluid is principally utilized for the HDPE pipe fittings because the tube blank, and is often spirally formed in temperature. It really is used for welding with double-sided submerged arc welding and is also mainly used for spiral seam welded steel pipe devices for pressure fluid transportation. The capacity in the steel pipe to stand up to pressure is strong as well as the welding performance can also be very good. After a number of rigorous scientific inspections and tests, the utilization situation is fairly safe and reliable. The solid diameter of the steel pipe is big, the transmission efficiency is also high, also it can effectively save the investment of laying pipelines. It is mainly utilized for pipelines that transport oil and natural gas.
2. General low-pressure fluid transport is mainly hot-rolled steel coiled tube blanks, often temperature spiral molding, using high-frequency lap welding way of general low-pressure fluid conveying spiral seam high-frequency welded steel pipe. Welding steel with spiral welds.
3. The hot rolled steel strip is used because the tube blank, which can be often formed by spiral molding and is made from double-sided submerged arc welding or high-frequency welded steel pipe. It is actually used for the foundation pile steel pipe for civil building structures, wharves, and bridges.
4. The overall low-pressure fluid transport is hot rolled steel strip coiled tube, regular temperature spiral molding, using double-sided automatic submerged arc welding or single-sided welding method for water, gas, air and steam as well as other general low-pressure fluid transport Submerged arc welded steel pipe.
5. The stress fluid transport is based on the hot-rolled steel strip for tube blanks, regular temperature spiral molding, high-frequency lap welding method utilized for pressure fluid transmission spiral seam high-frequency welding steel pipe device. The steel tube has strong pressure bearing capacity and good plasticity, which facilitates welding and processing. After qfsnvy number of strict and scientific inspections and tests, using safe and reliable, Multilayer pipe, transmission efficiency is also high, and may effectively save the laying pipeline investment. It is mainly utilized for the laying of pipelines connecting petroleum, natural gas, etc.