Engineered Polyamide 12 (PA12) liner for steel pipe rehabilitation and CO2 transportation under challenging conditions

Proceedings Publication Date:

22 Mar 2022
Silvia Helena Torrado Duran
Silvia Helena Torrado Duran, Mohana Murali Adhyatmabhatter
Part of the proceedings of

Material degradation leads to failures not only affecting operational costs but also bringing consequences to the environment and to human health. A novel safety and interactive liner design made of Polyamide 12 (PA-12) is presented as a unique solution for pipeline rehabilitation for CO2 transportation.

A special liner design based on PA-12 with an annular space carrying air pressure is planned, likewise a monitoring system to detect possible leaks (steel damage) through annular pressure drops. PA-12 shows its outstanding higher tensile modulus and superior creep characteristics which translate with even better hole spanning.

Compared to rehabilitation, building a new steel pipe requires higher investment and takes more than 1 year. A new approach to rehabilitate steel pipes under challenging conditions is described as a cost-effective alternative. The application includes formation of carbonic acid which may accelerate corrosion if left unchecked, specially where an external repair is not practical or even technically feasible. Then, PA 12 liner material become the most suitable candidate to rehabilitate due to its low permeation coefficient to CO2 and extraordinary mechanical properties.

In conclusion, tight fitting thermoplastic liners have been used for decades to protect steel against internal corrosion and abrasion, where the most common is HDPE. The novel is based on the PA-12 material which has an extremely low permeation rate for CO2 and high creep resistance enabling the plug of potential steel pipe pinholes. Furthermore, the benefit of a grooved design through which compressed air could be used to monitor leaks.