Ovality generally known as ‘Out of Roundness’ is one of the most common defects in pipe manufacturing. Ovality in early stages makes manufacturing process time consuming and less efficient. After dispatching, because of improper handling,... more
Ovality generally known as ‘Out of Roundness’ is one of the most common defects in pipe manufacturing. Ovality in early stages makes manufacturing process time consuming and less efficient. After dispatching, because of improper handling, ovality turns into barrier of proper welding of two pipes on site. In this paper, there is inclusion of causes of ovality, stages of ovality, drawbacks of oval pipes, manufacturing difficulties due to ovality and how to control it is included.
Puffiness formation can occur during process of pipelines component fabrication and transportation or during construction, operation, maintenance and their repair processes. The present paper addresses issues related to pipeline design... more
Puffiness formation can occur during process of pipelines component fabrication and transportation or during construction, operation, maintenance and their repair processes. The present paper addresses issues related to pipeline design and associated with the unintended actions due to external loads or ground movements. These may introduce longitudinal strains in the pipeline owing to combinations of curvatures and axial forces. Such scenarios can be tackled with Strain-Based Design approaches. Elaboration on checking the strain capacity of pipelines was achieved via the material testing in which a full-scale test was performed on a pressurized pipe under bending load. Numerical modeling procedures for predicting the structural behavior using certain assumptions are also described in this study. The result in local buckling hereafter referred to as puffiness. Such local damages are associated with large plastic deformations, substantial changes of the pipeline geometry and mechanical properties of its material.
