Pre-bending and sizing are the main steps within the spiral tube forming process. The key reason for 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 main reason for the sizing is to acquire a better diameter of the tube, because the diameter control is the main quality index of the steel tube. An appropriate match between pre-bending and sizing is required to obtain PEX-AL-PEX pipe.
This 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 unique: the submerged arc welding in the welding wire is exposed, there is absolutely no coating, submerged arc welding is definitely pre-paved welding flux to be welded The submerged arc welding wire extends into the flux, and also the arc is formed underneath the flux. The development process of the submerged arc welding is such that this welding wire is in touch with the workpiece.
After the start button is pressed, the welding wire and the workpiece are energized, and 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 burn under the flux layer, as well as the welding pool is actually created beneath the arc. Around the arc, the flux melts to form a cavity. The cavity as well as the pool carry on and advance, and the metal behind the pool solidifies to create a continuous weld. This process is performed underneath the flux, so we can’t see it with the human eye. It can 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 production auxiliary time is less, time for changing the welding rod is saved; the welding conditions are neat and no spatter, as well as the cleaning time is saved; the standard of the welding seam is high. In addition, it provides the necessary conditions for the delivery of the spiral welded pipe plant, so that the production period of the large spiral steel pipe is guaranteed, so it will be still popular.
1. The stress-bearing fluid is mainly used for the HDPE pipe fittings as the tube blank, and it is often spirally formed in temperature. It is utilized for welding with double-sided submerged arc welding and is mainly utilized for spiral seam welded steel pipe devices for pressure fluid transportation. The ability of the steel pipe to resist pressure is strong and the welding performance can also be excellent. After a variety of rigorous scientific inspections and tests, making use 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 an investment of laying pipelines. It really is mainly used for pipelines that transport oil and natural gas.
2. General low-pressure fluid transport is principally 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 rolled steel strip is utilized because the tube blank, which is often formed by spiral molding and is made from double-sided submerged arc welding or high-frequency welded steel pipe. It is actually utilized for the cornerstone pile steel pipe for civil building structures, wharves, and bridges.
4. The typical 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 way of water, gas, air and steam along with other general low-pressure fluid transport Submerged arc welded steel pipe.
5. The stress fluid transport is situated on the hot-rolled steel strip for tube blanks, regular temperature spiral molding, high-frequency lap welding method employed 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 selection of strict and scientific inspections and tests, using safe and reliable, PEX-AL-PEX pipe, transmission efficiency can also be high, and may effectively save the laying pipeline investment. It is mainly used for the laying of pipelines connecting petroleum, natural gas, etc.