Pipelines & Industrial Services
Detail
Description
Pipelines and pipes have a vital role in human health and also have strategic importance for all countries. Pipelines are constructed for transport of crude oil, refined petroleum, natural gas, biofuels and other fuels, clean water, hot water, steam transport and irrigation. These liquid and gaseous substances are necessary for continuation of human life, economic growth, industrial production, construction, infrastructure, agriculture as well as energy securit
Pipe laying /Pipe supply
Total construction time of a long pipeline project is mainly determined by pipe supply time and also pipe laying time. Pipe supply time is depended on pipe production speed of the pipe mill. Capacity and the speed of the pipe mill is directly related with steel plate travel speed and welding speed. In order decrease the pipeline construction time in big projects, total length has been divided 3 ,2 or more pipe suppliers, depending on their capacity and location. So, more than one pipe mill produce pipes and deliver to the site for pipe laying steps. High quality and defect-free pipe production is very important, especially on oil and gas pipelines projects, which have strict quality requirements and restricted project timing. Quality of the pipe or pipeline is the result of quality in raw material, pipe production steps; bending, welding, cutting, beveling, coating and also pipe laying steps; joint welding, testing, insulation, soil backfilling and restoration the disturbed area. The most critical steps which have big impact on total quality, are pipe fabrication welding and pipe join
Welding
Submerged arc welding is the main welding process to produce longitudinal or spirally welded pipes. Depending on the use of pipe, steel type, plate thickness and diameter of the pipe, inner weld and outer weld are done by one or multi wires in tandem submerged arc welding application. Welding properties and behavior of submerged arc welding fluxes are extremely important to have high quality and defect free weld under high production line speeds at high parameters. Mechanical properties, impact resistance, crack resistance, corrosion resistance, gas impermeability are main requirements from the pipe and weld joint. Inner and outer weld bead profiles are other important criteria’s to have good mechanical properties in the weld joint and homogenous paint and coating thickness. Proper welding flux, wire and approved welding procedure specification shall provide these necessary properties homogeneously through the pipe. Pipe joint welding is a difficult job due to site conditions. Generally pipelines pass through rural zones, where there is no electricity, cold and windy, ground can be inclined and wet, groove excavation is not always good enough to stand inside, so joint mounting, assembly and welding positioning is really difficult in such places. Welding job has to be performed defect-free, otherwise, cutting the defected pipe, preparation and remounting again is a big time loss for the project. Because of these reasons, experienced project managers and pipe welders pay attention to performance of welding consumables and welding machines/generators. High penetration, wetting and good blending the side walls of pipes, smooth weld profile without undercut, low spatter and easy positional welding, high mechanical properties, X-ray quality have to be provided by welding consumables, welding machines and orbital pipe welding syste