Production process of welded pipe spiral pipe

Production process of welded pipe spiral pipe

Production process of Welded Pipe spiral pipe

The development of Steel Pipe production technology began with the rise of the bicycle manufacturing industry, the development of oil in the early 19th century, the manufacture of ships, boilers and aircraft during the two world Wars, the manufacture of thermal power boilers after the Second World War, the development of the chemical industry, as well as the drilling and transportation of oil and gas, have strongly promoted the development of the steel pipe industry in varieties, output and quality. Usually steel pipe according to the production method, divided into seamless steel pipe and welded steel pipe two types, this is mainly to introduce welded steel pipe.

The production of welded steel pipe is the process of bending the tube billet (steel plate and steel strip) into the required cross-sectional shape and size of the tube with various forming methods, and then using different welding methods to weld the weld and obtain the steel pipe. Compared with seamless steel pipe welded pipe has the characteristics of high product accuracy, especially the wall thickness accuracy, simple main equipment, small footprint, continuous production, flexible production, wide product range of the unit, etc.

1.The raw materials of spiral steel pipe are strip steel coil, welding wire and flux.

 Before forming, the strip steel is levelled, trimmed, planed, cleaned, transported and treated with curved edges. The weld gap control device is used to ensure that the weld gap meets the welding requirements, and the pipe diameter, the amount of wrong side and the weld gap are strictly controlled. After cutting into a single steel pipe, each batch of steel pipe head three to carry out a strict first inspection system, check the mechanical properties of the weld, chemical composition, fusion status, surface quality of the steel pipe and through non-destructive testing, to ensure that the pipe process qualified, before officially put into production.

2.longitudinal submerged arc welding

The straight seam submerged arc welded pipe (LSAW) is generally made of steel plate as raw material, and it is formed by two sided submerged arc welding and expanding after welding through different forming processes.

The main equipment is milling machine, pre-bending machine, forming machine, pre-welding machine, expanding machine and so on. There are UO(UOE), RB(RBE), JCO (JCOE) and so on. The steel plate is first pressed into a U shape in the forming die, and then pressed into an O shape, and then carried out internal and external submerged arc welding, and after welding, it is usually expanded at the end or the full length range, called UOE welded pipe, and the non-expanded pipe is called UO welded pipe. The steel plate was rolled Bending, and then the internal and external submerged arc welding was performed, and the expanded diameter was RBE welded pipe or the unexpanded diameter was RB welded pipe. The steel plate is formed in the order of J-C-O. After welding, it is expanded into JCOE welded pipe or JCO welded pipe without expanding diameter

3.Straight seam high frequency welded pipe

The straight slit high frequency welded pipe (ERW) is produced by hot rolled coil formed by the forming machine, using the skin effect and proximity effect of high frequency current to melt the edge of the tube blank and perform pressure welding under the action of the extrusion roll.

Welded steel pipe, also known as welded pipe, is a steel pipe made of steel plate or strip after crimping and welding. Welded steel pipe production process is simple, high production efficiency, variety specifications, less equipment, but the general strength is lower than seamless steel pipe. Since the 1930s, with the rapid development of high-quality strip continuous rolling production and the advancement of welding and inspection technology, the quality of welds has been continuously improved, and the variety specifications of welded steel pipes have been increasing, and they have replaced seamless steel pipes in more and more fields. Welded steel pipe is divided into straight seam welded pipe and spiral welded pipe according to the form of weld. Classification by production method: Process classification - arc welded pipe, resistance welded pipe, (high frequency, low frequency) gas welded pipe, furnace welded pipe. The production process of straight welded pipe is simple, the production efficiency is high, the cost is low, and the development is fast. The strength of spiral welded pipe is generally higher than that of straight welded pipe, and welded pipe with larger diameter can be produced with narrower billet, and welded pipe with different diameter can also be produced with billet of the same width. However, compared with the straight seam pipe of the same length, the weld length is increased by 30 to 100%, and the production speed is lower.