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Mechanically Lined Pipes (MLP) Project Launched

Tue, 21 July, 2020

Clad and mechanically lined pipes (MLPs) are used in the oil and gas industry when production fluids are corrosive. In clad pipes, the corrosion resistant alloy (CRA) is metallurgically bonded to the backing steel, while in MLPs, a CRA sleeve is inserted into the backing steel and CRA weld overlay is used to seal the ends. In MLPs there is no bond between the liner and backing steel. Use of MLPs can result in 25 to 40% cost savings compared to clad pipes and so is an attractive option.

Despite recent research, there remain significant knowledge gaps, which need to be addressed in order to extend the use of clad pipes and MLPs.

As a result, TWI has launched a Joint Industry Project (JIP), State-of-the-Art Review of the Assessment Qualification and use of Mechanically Lined Pipes (MLP), which had its inaugural meeting on 22 June 2020.

The project will undertake a review of current and emerging practices as well as existing specifications to capture the current state-of-the-art for the manufacture and safe use of MLP.

The sponsors, who encompass the MLP chain from manufacturers to end users, and their industrial experience is pivotal to the project. As well as gathering information from existing specifications, standards and published literature, the various challenges associated with MLPs will be openly discussed, and the information supplemented by sponsor experience and technical data. TWI will also approach relevant organisations for information that is not in the public domain, if appropriate. This will enable the review to capture the state-of-the-art for MLP, resulting in a comprehensive guidance document for the sponsor group.

This review will also allow TWI to identify gaps in existing guidance so that future research can be focussed to address them.

The project team welcome additional sponsors at any time. For more information about the project and how your company or organisation can become involved, please email: or telephone +44 (0) 1223 899000.

For more information please email: