A spiral welded steel pipe
is a steel pipe which is welded and formed by a steel strip or a steel plate to be deformed into a circular shape or a square shape and has a joint on the surface. According to different welding methods, it can be divided into arc welded pipe, high frequency or low frequency electric resistance welded pipe, gas welded pipe, furnace welded pipe, Bondi pipe and so on. According to the shape of the weld, it can be divided into a straight welded pipe and a spiral welded pipe. Electric welded steel pipes are used in oil drilling and machinery manufacturing. The furnace welded pipe can be used as a water gas pipe, etc., the large diameter straight seam welded pipe is used for high pressure oil and gas transportation, etc.; the spiral welded pipe is used for oil and gas transportation, pipe piles, piers and the like.
Welded steel pipes have lower cost and higher production efficiency than seamless steel pipes
. Straight seam welded pipe has simple production process, high production efficiency, low cost and rapid development. The strength of the spiral welded pipe is generally higher than that of the straight welded pipe. It is possible to produce a welded pipe with a large diameter by using a narrow blank, and it is also possible to produce a welded pipe having a different pipe diameter by using a blank of the same width. However, compared with the straight pipe of the same length, the weld length is increased by 30 to 100%, and the production speed is low.
Therefore, most of the smaller diameter welded pipes are straight seam welded. For large diameter welded pipes, spiral welded spiral submerged arc welded steel pipes are used to bend the hot rolled strip into a spiral shape. The inner and outer seams are automatically welded by submerged arc welding. Welding is made into spiral seam steel pipe (also called spiral welded pipe, spiral pipe).