Lars Selling and Ingrid Andersson, Christophe Salles and Lars Höjer
Papers # 2010 Vancouver
Kungsors Plast AB, in co-operation with Borealis, has pioneered the underground plastic piping for petrol filling stations with the first polyethylene piping used by Shell Sweden in 1981.
The retail sector with petrol filling stations has used PE-based underground piping since the early 1980s. With increased awareness of environmental and health and safety risks involved the piping has developed from unlined polyethylene piping to advanced multi-layer products where new tooling and extrusion processes have emerged allowing for combinations of EVOH and electrically conductive materials that allow both for the prevention of hydrocarbon permeation as well as safe dissipation of static electricity to earth.
The combination of materials has made possible a PE-based pipe with extremely low permeation; the permeation results are so low that in 2010 German authorities accepted the pipe as having zero permeation and since the first installations of plastic piping for petrol fillings stations have been made. The choice of high performance bimodal PE80 and PE100 pipe compounds with very good mechanical properties is contributing to the durability and long-term performance of the whole system.
There is a clear trend towards increased safety to avoid environmental damage or risks related to health and safety. One such example is that oil companies and authorities are making secondary containment mandatory. Secondary containment for piping means solutions where an outer pipe provides added safety if the inner, fuel carrying pipe should leak. The interstitial space between the two pipes provides possibility for continuous monitoring and alarm should a leak occur. Piping systems have been developed to comply with the requirements that are also quickly being implemented in countries like China and India.
The solutions are also used in other applications like for the transport of LPG (Liquiefied Petroleum Gas) where operating pressures lie around 15 bars. Another example is where the pipe and the multi-layer technology for encasing a high voltage capacitor for ABB.
