Spiral piling pipe principal stress direction

In use process, spiral piling pipe principal stress direction, that indeed equivalent defective pipe axis length smaller than a straight seam pipe; Secondly, because pipeline are rolled steel, toughness greater isotropic, rolling along CVN value of the direction perpendicular to the rolling direction than CVN value three times higher.

Using wire brushes and other tools for steel suspension polished appearance, to remove loose or warped oxide, rust, welding slag. Hand open tools rust can reach Sa2 grade power tools rust Sa3 level can be reached, if the appearance of adhering solid steel iron skin, tools rust effect is not fantasy, anti-corrosion construction requests reach the depth of anchor pattern pickling. Straight seam welded pipe suffered precisely perpendicular to the principal stress impact to the lowest pipe direction, while spiral steel pipe is staggered a minimum impact to the direction of the spiral weld pipe changed to the advantage of long upwind. Spiral steel pipe anti-corrosion method is also a process from which restrain the hands. If the pipe wall plus anti-corrosion coating, can increase the loop resistance, adding corrosion current; external DC power supply, so that the soil pipe constitutes a negative potential, constitute cathodic protection can eliminate the potential difference between anode and cathode, anode and cathode from basically abort the process aborted. Rule of law, anti-corrosion coating table, cathodic protection law standard. But once the anti-corrosion coating is damaged, partially exposed iron will slow localized corrosion. Therefore, anti-corrosion coating and cathodic protection phase separation is the way to rid the table of the economic and void.