Quasi-Static and Dynamic Deformation of Polymer Coated Pipes

Abstract

Offshore pipelines are occasionally subjected to accidental impact loads from trawl gear or anchors, which may damage the pipeline. This study reports the results of material and component tests carried out on offshore steel pipes and an adhering polymer coating. The polymer coating is primarily applied for corrosion protection and thermal insulation. Despite not necessarily being designed for it, the polymer coating does have some structural capacity, and it is this capacity that is the main topic of investigation herein. In design codes and guidelines, coating is traditionally not accounted for when determining the energy absorbed by a pipeline during impact. This makes the estimates provided overly conservative. The goal of this experimental work is then to investigate whether a typical polymer coating makes any significant contribution to the energy absorption properties of a pipeline cross-section during impact. To this end, both dynamic and quasi-static denting tests of full-scale pipe cross-sections are carried out. All pipes tested have a length of approximately 1 m. The sharpest indenter from the guidelines is used, as a sharper indenter is more likely to penetrate compared with a blunter one. Based on the tests, the polymer coating can absorb a notable part of the kinetic energy delivered to the system. More tests with different coating and pipe thicknesses are needed to quantify this effect.

Mechanical Modeling of the Polymeric Coating on a Subsea Pipeline

“…Other pipeline samples from the same batch have previously been studied in terms of the coating products ability to absorb energy during impact events [2,6]. Previous studies [5] revealed a strong variation in the porous morphology throughout the thickness of the Porous PP with possible implications for the mechanical response (and thus energy absorption) of the full coating. It is these implications that are further examined herein.…”

“…Prevailing standards and design guidelines are allowing for thermal coatings to be included however, their effectiveness must be documented [3,4]. This may be done with full-scale componentspecific experiments [5,6]. However, a cost-effective alternative to expensive experimental programs are found in numerical techniques as the finite element method.…”

Underwater Laying of Pipes for Heating Networks of Energy Systems

“…Various techniques and devices for laying underwater pipelines, materials for repair are discussed in [1][2][3][4][5]. The influence of external conditions on the strength characteristics of underwater pipelines are considered in [6][7][8]. Various thermal insulation coatings for subsea and buried pipelines are presented in [9][10][11][12] [13][14][15][16][17][18][19] However, the authors did not consider the way of laying conduits across the water barriers along their bottom, the use of which provides the opportunity to choose the most cost-effective option of the technical solution enhancing the economic performance of energy systems and complexes.…”