At the Rooppur NPP, the Teplotech 4.0 project been launched ahead of schedule to ensure the technical upgrading of heat installation works, including the commercial use of two types of automatic orbital welding machines.
The use of new automatic welding machines has been promptly agreed with the design organization and supervisory authorities owing to the collaboration of Energospetsmontazh JSC and the ASE JSC Center for Technology Transfer and Technical Policy.
Three automatic argon-arc welding sets (AAWS) and an argon-arc automatic-pressing welding set are being operated now at the Rooppur NPP construction site. Earlier, at the stage of NPP heat installation works, such sets were not commercially used. They were tested during the construction of the Novovoronezh NPP-2 (NVNPP) and the Belarus NPP.
The welding by AAWS is done 15% faster than by a welder. Their main advantage is ensuring a permanent high quality of seams. The use of these sets at the NVNPP has shown that there is no need to redo the work done by automatic tools, while defective products are attributed sometimes to human failings and we have to spend time to remedy them. These sets have been used at the Rooppur NPP since September, but they will be operated in full swing next year.
The Bengali personnel were trained to operate the AAWS. The training classes were arranged immediately in the workshop. The students completed a 16-hour classroom training course that was followed by a two-week on-the-job training.
The AAWS purchased by Energospetsmontazh JSC use the argon-arc welding technology with automatic wire feed. The operator needs only to adjust the machine to the the pipeline properties.
Another new automatic machine is operated on the basis of the argon-arc welding technology by using the automatic-pressing welding (flashing) method.
The automatic welding technology using the automatic-pressing method supports a joint welding to be done 40% faster than by a professional welder. In this case, it is not required to prepare pipe joints. This technology is limited only by the diameter and wall thickness of the pipe being welded. Therefore, the automatic pressing welding machine is used at the Rooppur NPP simultaneously with the AAWS.
“It is important for us that the AAWS and automatic-pressing welding can be performed not only by welders, but also by operators who can be trained in two weeks. There are often enough installation fitters at our construction sites, but qualified welders are always sought-after. The main advantage of the automatic machines is that we can ensure high quality and speed of the welding, by making the welders available to perform more complicated installation works”, says Denis Kalinin, head of the Energospetsmontazh JSC production system development department.
