For many years now, Mannesmann Line Pipe has supplied steel pipes with a single- or two-layer fusion-bonded epoxy (FBE) coating to offshore and onshore projects. This coating offers efficient corrosion protection and is suitable for the most varied pipe-laying methods and difficult soil conditions, including mechanical loads.
Mannesmann Line Pipe supplies FBE coatings to all relevant standards and specifications, such as CAN CSA Z245.20, ISO 21809-2, AS 3862, API RP 5L2 and NACE RP 0394, or according to GBE/CW 6.
FBE coatings can be applied in layer thicknesses of between 350 µm and 1000 μm. The maximum permissible service temperature in continuous operation is 90°C.
At Mannesmann Line Pipe, FBE coatings (single- or two-layer) are made exclusively from proven and approved materials and applied using an electrostatic spraying technique.
Thanks to its outstanding mechanical properties and adhesion, FBE is highly resistant to cathodic tunneling, which helps to limit the operating costs of cathodic corrosion protection systems.
Single-layer FBE coating
Single-layer FBE coatings protect buried pipelines against corrosion and mechanical damage. The average layer thickness of this coating variant is 400 to 500 μm.
Two-layer FBE coating
The first layer of this coating type serves mainly for corrosion protection, while the second layer serves as mechanical protection in the case of increased external loads.
For the second layer, either the same material as for the first layer may be used or, in the case of applications involving increased service loads, an abrasion-resistant overlay (ARO). The second layer is particularly designed to provide protection against mechanical impact and abrasion. It is applied using the same technique as for the first layer (wet-on-wet) to an average minimum thickness of about 400 to 500 μm.
The second layer for non-buried pipelines, such as pipe bridges, consists of an UV-resistant polyester. It is also applied to a thickness of 400 to 500 μm.
In offshore projects, FBE is frequently combined with a ballast coat of cement mortar. In this case, the second FBE layer is usually applied as a so-called rough coat, which provides increased shearing resistance to prevent the cement mortar coat from slipping off as the heavy pipe string is lowered to the seafloor.