Watt Drive, a WEG Group Company, delivered the entire drive technique for a large-diameter pipe plant. The drives are used for the pipe transport system, the welding stands and the turning devices.

Machinery description
The project was realised by the company DANIELI W+K Industrie Technik GmbH & Co. KG from Dortmund.
Hot rolled strip in the coil is used as base material for the manufacturing of spiral pipes. It is formed into a spiral-formed pipe body and directly after that welded ready with the submerged arc welding technique. This technique is used for the inner- and outer seam and is performed simultaneously.

Transport systems
Pipes with a diameter of 508mm (20“) up to 2540mm (100“) are conveyed with the transport system (see picture 1). The hugest pipe with a length of 18m thereby weighs 27 tons. The maximum conveying speed is 30m/min and is kept constant at all pipe diameters with geared motors that are energised by frequency inverters.

Implemented drives: 223 shaft mounted geared motors ASA 66A 81N4 TH
Motor power: 0.75kW
Output speed n2: 15U/min
Output torque M2: 481NM
Service factor: 1.7

Drive concept
In the range of 5 - 50Hz the drives are run with a constant torque, in the range of 50 – 110Hz with field weakening (constant power).
Huge pipe diameter– high weight with the need of high torque – at low speed.
Small pipe diameter – low weight with the need of low torque – at high speed.

Turning devices
Drives with brakes are implemented for the turning devices (see picture 2). This enables a precise and step-by-step quality check of the spiral pipes. The pipes are examined by visual or x-ray check.

Implemented drives: 52 shaft mounted geared motors ASA 66A 81N4 BR5 TH
Motor power: 0.75kW
Output speed n2: 12U/min
Output torque M2: 577Nm
Service factor: 1.4