The spiral steel pipe belongs to the welded pipe, which means that the steel chain or thick steel plate is bent and deformed into a ring, square, etc., and then welded by electric welding, and the surface has a seam. The ingredients selected for welded pipes are thick steel plates or hot-rolled strips; they are classified according to the welding process. Welding process classification Spiral steel pipe can be divided into arc welded pipe, high frequency or low frequency resistance welding machine pipe, gas cutting pipe, spiral steel pipe and so on according to different welding processes. Electric welded steel pipe: used in crude oil drilling and machining industries, etc. Spiral steel pipe: It can be used as water gas pipe, etc., large-diameter spiral steel pipe is used for high-pressure gas transportation, etc.; spiral steel pipe is used for gas transportation, prefabricated piles, bridge piles, etc.
According to the welding posture, it can be divided into spiral steel pipe and spiral steel pipe straight seam welding. The production process is simple, the production is high efficiency, low cost, and the development trend is faster. It can produce welded steel pipes with large diameters, and can also use blanks of the same overall width to produce welded steel pipes with different diameters. However, compared with the same length of spiral steel pipe, the welding length is increased by 30-100%, and the production rate is lower. Therefore, most of the welded steel pipes with larger diameters use straight seam welding, and most of the large-diameter welded pipes use spiral welding.
Spiral steel pipe is divided into two types: automatic arc welding seamless steel pipe and high frequency welding machine seamless steel pipe. Spiral seam automatic arc welded seamless steel pipe is divided into two categories: class A tube and class B tube according to the working pressure of conveying materials. Class A pipes are generally welded with general spiral steel pipes Q235, Q235F and general low-alloy tool steel 16Mn, and Class B pipes are welded with stainless steel plates such as Q235, Q235F, Q195, etc., as the fluid mechanics transport pipe fittings with low working pressure. Welding machine seamless steel pipe spiral seam high-frequency welding machine seamless steel pipe, there is no consistent product implementation standard, generally use the general spiral steel pipe Q235, Q235F and other stainless steel plate production and production.