Hello Pipe Enthusiasts!
Welcome back to #SEAPIInsight. In the previous article, we covered “Characteristics of Genuine Southeast Asia Pipe Industries Steel Pipes.” This time, we will delve into the Three Roll Bending & Mechanical Expanding forming processes, which serve as the backbone of Longitudinal Sub-merged Arc Welding (LSAW) steel pipe production at PT. Southeast Asia Pipe Industries (SEAPI). These processes ensure every pipe achieves high dimensional precision, optimal ovality control, and consistent shape—features crucial for heavy-duty applications such as oil, gas, and energy transmission, marine construction, and large structural foundations.
Behind the quality and strength of the LSAW steel pipes produced by PT. Southeast Asia Pipe Industries (SEAPI) lies the core forming processes: Three Roll Bending & Mechanical Expanding. As a flagship capability at SEAPI, this combined technology is engineered to deliver pipes with superior dimensional precision, optimal ovality control, and consistent geometry for demanding industrial uses like oil and gas transmission, marine construction, and major structural foundations.
Three Roll Bending
Three Roll Bending is the process of forming steel plate into a cylindrical shape using three main rolls, upper, middle, and lower—that operate in a controlled sequence to bend the material gradually. Unlike other forming methods, Three Roll Bending offers flexible adjustment of plate thickness and pipe diameter while minimizing residual stress and potential deformation during forming.
Mechanical Expanding
Mechanical Expanding is a mechanical forming step applied after welding to enhance diameter precision, ovality control, and straightness of the pipe. It also serves as a stress-relief mechanism that reduces residual stresses in the steel, thereby improving the pipe’s strength and toughness.
In this process, an expander machine with a specified stroke is inserted inside the pipe to achieve the target expansion ratio in accordance with standards (as required by clause 8.9.2 of API Spec 5L 46th Edition: minimum 0.3% and maximum 1.5% expansion).
Technological Excellence, Guaranteed Reliability
By leveraging Three Roll Bending & Mechanical Expanding, SEAPI ensures every LSAW steel pipe off the production line is ready to deliver peak performance in the field. The integration of these two forming technologies enables SEAPI to produce steel pipes with dimensional and mechanical properties that outperform other domestic manufacturers.
For high-precision steel pipes that withstand the toughest heavy-industry demands, trust SEAPI’s expertise and commitment.
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