LSAW steel pipe production process is quite simple, the main production process is high-frequency welding and submerged arc welding, welded pipe production is with high efficiency, low cost, rapid development. Spiral welded longitudinal generally higher than the core production process is submerged, different spiral welded pipe can produce the same width of the billet diameter, you can also use narrow the billet to product large diameter pipe. However, compared with the same length longitudinal weld length of 30 to 100%, and lower production rate. Therefore, most of the smaller diameter pipe straight seam welded, large diameter spiral welded pipe for the most. T-welding technology will be used when producing large-diameter welded pipe industry, is about a short segment Longitudinal then butt, then a chance of meet the length, T Longitudinal welding defect engineering needs also greatly improved, and T-weld welding residual stress is large, the weld metal are often in three-dimensional stress state, increasing the likelihood of cracks at. 

The difference between lsaw steel pipe and ssaw steel pipe
Welding process in terms of: spiral welded pipe and Longitudinal consistent welding method, straight seam steel pipes inevitably there will be a lot of T-weld, so the probability of the existence of welding defects is also greatly improved, and the welding residual stresses than T welds large, often in the weld metal three-dimensional stress state, increasing the likelihood of cracks. Moreover, according to the provisions of the submerged arc welding process, and each shall have the arc welds and extinction at the office, but when each longitudinal seam welding ring, unable to meet the conditions, which may be at the extinction more welding defects. 

Spiral Pipe Weld degree helix angle is generally, therefore spiral weld resultant stress is the highest stress. Under the same operating pressure, spiral steel pipe of the same diameter than the longitudinal wall thickness can be reduced. 

Both yield pressure or burst pressure. Spiral steel were lower than longitudinal. Burst test also shows the mouth of the ring spiral pipe bursting was significantly greater than the rate of deformation longitudinal. Thus confirmed that the spiral steel pipe plastic deformation than longitudinal, blasting mouth generally confined to a pitch, which is spiral weld on the expansion gap of a strong binding effect due. 

Trends of the development of the pipeline is large-diameter, high strength. With the increase of pipe diameter, the steel grade increases, the greater the ductile fracture tip generated steady expansion trend. Spiral steel pipe and straight seam welded pipe are as a level, but the spiral steel pipe has higher impact toughness.