The introduction of spiral welded steel pipes

Spiral welded steel pipe is a kind of 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. 

Straight seam welded steel pipes have simple production process, high production efficiency, low cost and rapid development. The strength of the spiral welded steel 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, and the large diameter welded pipes are mostly spiral welded.

Common material garde:

Q235A, Q23b, 0Cr13, 1Cr17, 00Cr19Ni11, 1Cr18Ni9, 0Cr18Ni11Nb. Q345 L245 L290 X42 X46 X70 X80

manufacture standard:

GB/T 9711-2011 (national standard, also called oil and gas industry, delivery steel pipe delivery technical conditions, the first part: A-grade steel pipe (to the current strict requirements have GB/T9711.2 B-grade steel pipe)), API-5L (US oil Association, also called pipeline steel pipe; which is divided into two grades of PSL1 and PSL2), SY/T5040-92 (spiral submerged arc welded steel pipe for pile)