How to cut thick wall spiral welded pipe?

Posted by zora li on November 2nd, 2023

Spiral steel pipe (SSAW steel pipe) is a welded pipe made by rolling low-carbon carbon structural steel or low-alloy structural steel strip into a pipe blank at a certain spiral angle (called forming angle), and then welding the pipe seams. Different spiral welded pipes should have different cutting methods. The cutting methods of thick-walled spiral welded pipes are as follows:

(1) Cutting method
This shearing machine has high productivity and no metal consumption during shearing. However, due to the flattening phenomenon at the fracture, it is easy to cut at an angle. At the same time, the shearing machine is also easy to cut at an angle when shearing high-alloy steel. Therefore, shears are generally only used on small units with a large number of shears and products made of low alloy steel and carbon steel.

(2) Sawing method
The end face of the rust-removed pipe blank on the sawing machine is straight, which is convenient for centering when perforating and easy to operate. The wall thickness of the hollow blank (capillary tube) is relatively uniform. At the same time, a cold rust remover can be used to cut tube blanks of various steel types. But its disadvantages are low productivity and high saw blade loss.

(3)Breaking method
The productivity of the breaking machine is high, but the section of the broken tube blank is extremely uneven, and it is easy to cause uneven wall thickness during perforation. At the same time, it is also difficult for mild steel and alloy steel to break. Therefore, crushers are generally used on old units and are generally not used on new units.

(4) Flame cutting method
The flame cutting spiral welded pipe blank has a flat section, the cutting seam is about 6-7mm, and the investment cost is relatively low. At the same time, the flame cutting machine is flexible in production. It can cut both round billets and square billets, and can cut spiral welded pipe billets of most steel types. The disadvantage is that general flame cutting methods are not suitable for carbon steel and some alloy steels with a carbon content exceeding 0.45%. At the same time, problems such as metal consumption, oxygen and gas consumption, and workshop pollution will also occur.