Reel-laying is a fast and cost effective method to install pipelines since the time consuming operations of welding and inspection are conducted onshore. During reel-laying repeated plastic strain is introduced into a pipeline which may affect strength and ductility of the line pipe material. Based on the experience, it has been shown that the small-scale reeling test procedure according to DNV-OS-F101 [1] is a good way to inspect the mechanical properties for the reel-laying process. Coupons from pipes are loaded in tension and compression tests and aged if required. Specimens for mechanical testing are machined from these coupons and tested according to the corresponding standards.

This paper demonstrates current efforts to demonstrate the usability of cold-formed HFI pipes from Salzgitter Mannesmann Line Pipe GmbH (MLP) for the reel-laying process. In a first step the results of the pre-strained materials are compared in extensive material tests with the undeformed incoming materials. The effect of thermal aging from the coating process on the reeling behavior is then examined, in relation to the background of thermal aging. In discussing the difference between compression and tension zone of the reeled pipe, the influence according to the load conditions is analyzed by the material property tests. This paper demonstrates current efforts of the availability for use of cold-formed HFI pipes for the real-laying process. In addition, the report notes the difference and the effects of the material properties to testing according to the strain-based or stress-based load conditions. In discussing the influence of the tempered conditions of the mechanical properties, therefore two different pipe conditions are investigated by the small scale-reeling (SSR) testing procedure. In summary the results of the pre-strain materials are comparable with the unformed incoming materials.

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