Zhejiang Kingland puts spiral pipe plant from PWS into operation

Zhejiang Kingland Pipe Industry, based in Huzhou City, Zhejiang Province, China, has successfully commissioned a spiral pipe plant supplied by PWS. With its use of "PERFECT^® arc" the plant meets Ecoplants criteria in terms of sustainability and offers energy savings of up to 30 percent compared to competitor plants. What's more, productivity is increased by up to 20 percent.

The plant comprises a spiral pipe forming and tack-welding machine for forming and pre-welding hot rolled steel strip as well as three downstream offline finish-welding stands. It has a capacity of 200,000 tons per year. Zhejiang Kingland is able to extend the spiral pipe welding plant by a fourth finish-welding stand and thus increase capacity to 260,000 tons per year.

The newly developed "PERFECT^® arc" welding current sources are used for the welding machinery. No transformers are required here, the systems are operated using IGBT (Insulated-Gate Bipolar Transistor) power electronics, with the welding current completely digitally controlled. As a result the welding machines can attain an efficiency rate of over 90 percent. Compared to older welding techniques energy savings are up to 30 percent, depending on the operating point. In addition, productivity is increased by up to 20 percent, while process stability remains consistent.

Another benefit is the reduced transfer of heat into the pipe. For this purpose, the process parameters are adapted for each individual welding wire, in order to prevent unnecessary heat being transferred into the pipe material. This is particularly important for high-strength steels.

Zhejiang Kingland uses its offline spiral pipe welding plant to produce pipes to API 5-L PS2 standard with an outside diameter of 508 to 1,626 millimeters (equivalent to 20 to 64 inches) and wall thicknesses of 6.35 to 25.4 millimeters (equivalent to 1/4 to 1 inch). The pipes are 8 to 12.5 meters in length. The plant processes high-strength steels up to API grade X100.

Shaping and high-speed tack-welding of a pipe

Based on SMS Group information