Straight seam welded pipe is gradually formed by high frequency welded pipe rolling, and then welded into steel pipe by high frequency heating, and external burrs are scraped with a scraper. Finally, through shaping, sizing and straightening sawing, a straight seam welded pipe of the desired size is produced. This is what we usually call the direct welded pipe production mode.

The difference between direct welded pipe and spiral welded pipe is that the weld of spiral welded pipe is spiral curve, but they are welded pipe. The spiral tube is formed from the steel plate through the drum machine, and then welded to the steel tube by submerged arc welding or electric welding, and then sizing and forming on other forming equipment. This kind of pipe production efficiency is low, pipe quality is unstable, dimensional accuracy is low, but the equipment is simple, less investment. Direct welded pipe equipment high efficiency, good quality, high precision, good uniformity.