The pipe structure consists of a polymer liner which is reinforced by layers of high strength steel strip a fiber optic cable for integrity monitoring and two outer layers of environmental protective coatings. The end fitting system consists of a stem which is swaged into the polymer liner and an outer sleeve which incorporates connections for optical fiber and cathodic protection as well as a gas venting port.
The polymer line pipe provides fluid tightness and is resistant to corrosion as well as being immune to hydrogen embrittlement. For temperatures below 80C HDPE can be used with other polymers such as PA12 or PVDF for higher temperatures. The choice of polymer can be tailored to the chemical composition and temperature of the fluid being transported.
The steel reinforcement consists of spirally wound overlapping high strength steel strip with a patented interlock. The steel grade is specially developed to have high ductility as well as high strength and has been proven in safety critical applications in the automotive industry.
The fiber optic cable is a bundle of fibers inside a protective sheath and can include spare fibers for communication and digital integrity monitoring.
Environmental coatings are wound over the steel reinforcement encapsulating the optical fiber. These are an inner high adhesion self-healing layer that repels oxygen and moisture and an outer tough layer that also provides scuff resistance.
The swaged end fittings include an inner stem which engages with the polymer liner and an outer steel sleeve with connection points for optical fibre cable and for cathodic protection. Vent ports can relieve permeated gas accumulations between the liner and the reinforcement layers.