​Two ways of high frequency straight seam welded pipe unit welding

There are two ways of welding for high frequency straight seam welded pipe (ERW) units: contact welding and induction welding.
Contact welding is that a pair of copper electrodes are in contact with both sides of the welded steel pipe, and the induced current has good penetration. The two effects of high-frequency current are utilized because the copper electrodes are in direct contact with the steel plate, so the welding efficiency of contact welding is higher It has high power consumption and low power consumption, and is widely used in high-speed and low-precision pipe production. Contact welding is generally required when producing particularly thick steel pipes.

But there are two disadvantages when contact welding:
First, the copper electrode is in contact with the steel plate and wears quickly;
Second, due to the influence of the flatness of the surface of the steel plate and the straightness of the edge, the current stability of the contact welding is poor, and the internal and external burrs of the weld are relatively high, so it is generally not used when welding high-precision and thin-walled pipes.

Induction welding is to wrap one or more turns of induction coils outside the welded steel pipe. The effect of multi-turns is better than that of single-turns, but the production and installation of multi-turn induction coils is more difficult. The efficiency is higher when the distance between the induction coil and the surface of the steel pipe is small, but it is easy to cause discharge between the induction coil and the pipe. Generally, it is advisable to keep the induction coil with a gap of 5~8 mm from the surface of the steel pipe.

When induction welding is used, since the induction coil is not in contact with the steel plate, there is no wear, and the induction current is relatively stable, which ensures the stability during welding. When precision pipes are used, induction welding is basically used.

Precautions for debugging and daily maintenance of welded pipe unit:
Generally speaking, the formulation of the welded pipe unit must comply with the operating rules. The operator must not contact the mold during the operation of the unit, and pay attention to placing his hands in the direction of the pipe to avoid improper operation.
In addition, the operator of the welded pipe unit should pay attention to check whether the lubrication points of the unit are properly lubricated before operation. Otherwise, they should pay attention to adding some lubricating oil to ensure the normal operation and work of the unit.

Article source: https://article-realm.com/article/Finance/19719-Two-ways-of-high-frequency-straight-seam-welded-pipe-unit-welding.html