Spiral submerged arc welded pipe unit classification

Under normal circumstances, according to the different production methods of spiral submerged arc welded pipe units, the production of spiral welded pipe units is divided into continuous production and intermittent production.

Continuous production is to set up a looper on the spiral welded pipe production line to ensure that the forming and welding are not interrupted when the two rolls of steel strip are butted; the intermittent production is that there is no looper on the spiral welded pipe production line, and the two rolls of steel strip are docked. At the time, the molding and welding are paused (the weld is intermittent, and repair welding is required later). Some continuous units do not have a looper device, and a flying welding device (mobile trolley type butt welder) can also ensure continuous production.

The flying welding type preparation unit installs the front preparation equipment of the spiral welded pipe unit—the uncoiler, the leveler, the shearing machine, the butt welding machine and the delivery device on the trolley, so that the preparation work is completed on the trolley. When a roll of strip is to be used up, the unwinding and leveling of the new strip and the welding of the tail of the previous strip are completed during the trolley. The utility model has the advantages that the spiral welded pipe unit without the steel strip is not stopped, the continuity of the steel pipe forming welding process is maintained, the arc breaking caused by the parking of the unit is reduced, and the production efficiency of the unit requiring the head stop is high, and the production stability is good. With the increase of the strength grade and thickness of the coil, the conventional deep pit type loop storage device has not been applied. The flying welding type preparation unit is an ideal equipment for ensuring continuous production of spiral welded pipe. Large, infrastructure investment is higher.

At present, spiral welded pipe units at home and abroad have different adjustment methods according to the forming angle, and can be basically divided into two categories: front swing type spiral welded pipe unit and rear swing type spiral welded pipe unit. The difference between the two types of units is that the forming angle needs to be adjusted when changing the pipe diameter, the front pendulum unit is not moving, the front axle is swung (from the unwinding machine to the inlet guide before the former), the front axle center and the former The angle of the center line is the forming angle. The rear axle part of the front pendulum spiral welded pipe equipment is only fine-tuned, and the swing angle is small. It is suitable for the production of long steel pipes, such as pipes for construction piles, and the welds of the pipes are allowed to repair welding. In the rear swing type unit, the angle between the strip conveying line and the center line of the former is the forming angle. From the uncoiler to the inlet guide, the angle of the forming machine turntable and the rear axle is adjusted to adjust the forming angle. The rear swing type rear axle is used to adjust the forming angle. The required floor space is large when the pipe is long, but the weld seam is continuous, the weld quality is high, and the output is large, which is suitable for the production of API grade pipes.

In terms of the positioning method of the strip, the front swing type is the center positioning mode, and the rear swing type is the side positioning mode, and the difference of the positioning modes may be different when the type is adjusted.

(1) Front swing type unit and features Front swing type welded pipe unit, all equipment are installed on the front and rear bridges. With the former as the boundary, the former is the front axle and the former is the rear axle. The rear axle is mainly equipped with welding equipment, flying shears, centralizers and steel pipe output roller roads; the front axle is mainly equipped with unwinding machines, leveling machines, delivery machines, disc shears and edge milling machines. Compared with the rear pendulum unit, the main advantages of the front pendulum unit are:

1 unit is short, small footprint, saving investment;

2 It is easy to change production specifications, suitable for the production of small batch and multi-size steel pipes;

3 Due to the compact arrangement of equipment and concentrated processes, production capacity can be reduced. Under normal circumstances, 7-8 people can organize production;

4 is easier to achieve automatic control.

There are also some disadvantages:

1 After the production of each coil of steel coils, the new steel coils need to be stopped for waiting, and the steel strips are docked. Therefore, the production efficiency of the equipment is not high, the output is small, and the weld seam of the pipe is not continuous;

2 Due to the short unit, the monthly bending of the steel strip and the delivery deviation are not easy to correct, and the dimensional forming has a great influence. From the current development of spiral welded pipe units at home and abroad, the number of new front swing type units is greater than that of rear swing type units. Of course, the choice of the specific layout type of welded pipe units cannot be generalized, and should be based on product market positioning and unit characteristics. .