Mönchengladbach, March 08, 2018

Service packages for ERW-tube welding and profiling lines

Minimizing downtimes due to wear by modernizations

SMS group as the largest supplier of machines and plants for tube production worldwide has built more than 2,100 reference plants and machines since 1960, including more than 350 tube welding lines. It is one of the world’s few companies offering all core components for the production of longitudinal seam-welded pipes and sections. The plants cover a production range for diameters from 10 to 660 millimeters and variable wall thicknesses. As reliable life-cycle partner of the customers, the service experts accompany the tube welding and profiling lines, as well as the downstream finishing lines. The services range from specific equipment checks for analyzing the plant condition through erection and commissioning and training of the operating staff up to technical assistance. In the course of this, the service experts accompany the customer with their OEM know-how when optimization measures are performed and offer solutions according to his needs. SMS group provides spare parts procurement worldwide or offers preventive concepts of spare parts storage to the customer to minimize downtimes.

Efficient service packages for ERW-tube welding lines

Whether precision tubes, OCTG tubes (Oil Country Tubular Goods) or structurals – the markets demand first-class quality within close tolerances. SMS group service supports plant operators in meeting these high market requirements. With targeted repair and modernization measures of highly stressed components susceptible to wear of an ERW-tube welding line the plant remains competitive. Here in particular, the plant components for strip preparation, the mill stands and the HF generators for forming and welding, the MF seam-annealing systems for normalizing the weld area, and the components for roll-pass design and cut-off are in the focus of the service experts. For these and other core areas of the ERW-tube (Electric Resistance Welding) welding and profiling lines SMS group provides efficient service packages. For customers this means: calculable cost and scheduling reliability and guarantee for upgraded plant components. SMS group also supports modernizations and services for plants from other suppliers.

Examples of modernization in strip preparation

With the knowledge of the plant manufacturer, SMS group upgrades all individual components in strip preparation: from uncoiler up to horizontal spiral strip accumulator within the scope of a service package. It is the task of the spiral strip accumulator to ensure that the strip is continually transported into the cross welder. With the modernization, the customer receives a reliable and low-maintenance accumulator system contributing to an increase in productivity and an improvement of plant availability. The cross welder in an ERW-tube welding line serves to connect head and tail end of the strip to form an endless strip. It is arranged between strip leveler and spiral strip accumulator and is also regarded as sensitive issue in tube production since the entire manufacturing process may be endangered by defective welding processes or failing welding power sources. SMS group service makes sure that this scenario is prevented by modernization measures performed in a timely manner. Depending on the condition, it may be a complete replacement or partial upgrade of mechanical, hydraulic or electrical plant components.

Renewal of forming and welding areas

The precisely formed open-seam pipe is welded in a welding scaffold of an ERW-tube welding line by means of the HF process while the pipe is positively locked by weld rolls compressing the heated strip edges with a defined upsetting pressure to ensure that the welding process is properly executed. The inductive heat input of the HF weld into the strip edges requires permanent cooling of the weld rolls by means of water emulsion. The welding scaffold needs to be modernized completely or partially when individual plant components are worn, e.g. the upsetting forces of the weld rolls on the pipe circumference, by the heat input of the HF welding process or by scale accumulation. Here, bearings for side rolls, top rolls and bottom rolls, but also guide elements on the change plates for roll adjustments may be affected. A modernization is also useful when an existing welding scaffold should be expanded by the CSS-Quicksetting® (Computerized Setting System). The system speeds up product changes by automatic, reproducible roll adjustments. Depending on the degree of wear or the customer’s targets, SMS group service performs partial upgrades of mechanical, hydraulic and electrical plant components or replaces an existing welding scaffold completely.

Modernizations for roll pass design, profiling and cut-off

Also for the final production processes in an ERW-tube welding line SMS group offers suitable modernization modules. A good example of this is the travelling section tube cut-off unit. This configuration features a multicut system. Cutting almost without burr is carried out with two carbide saw blades rotating around the tube in an orbital way. Since the travelling cut-off unit is operated continuously during tube production it may be necessary to have a complete or partial modernization performed by SMS group. Through continuous operation, individual plant components are under remarkable stress and are thus subject to heavy wear. This includes in particular the guide units for longitudinal movements of the complete cut-off unit and the guide units for orbital motions. Due to the technological progress in certain time intervals, the electrical equipment such as PLC control and automation should also be brought up to date.