INTERNAL LININGS AND
EXTERNAL COATINGS FOR
J. Alan Kehr
Technical Marketing Manager
Corrosion is a global problem, consuming 3 to 4 percent of gross national product
in the developed countries of the world.1 Selecting economical and effective tech-
niques for minimizing the effects of corrosion is a critical design decision in pipelines
as well as in other technologies. Protecting pipeline systems from corrosion is
essential to prevent leaks and consequent possible environmental disasters, fire and
explosion, personal injury, service disruption, and costly maintenance. Protective
measures are critical, yet they represent only a small fraction of the long-term
overall cost of a pipeline system. The effectiveness of the corrosion-prevention
system has a direct bearing on the design life of the pipeline and significantly
influences operational costs such as general maintenance, pumping energy, and
This chapter reviews fusion-bonded epoxy (FBE) coatings, three-layer polyolefin
coatings which utilize FBE as the primary corrosion coating, and FBE linings as
solutions for mitigating external and internal pipeline corrosion.
Higher operating temperatures in modern pipeline systems and a host of hostile
environmental conditions during transportation, installation, and use require a new
generation of FBE-based world-class coatings to protect the pipe exterior.2 The
FBE primary coating controls the steel/coating interface where corrosion begins.
Advanced field application technology provides comparable-quality same-system
coatings for the girth weld.
GENERIC DESIGN CONSIDERATIONS
Higher levels of hydrogen sulfide (H2S), carbon dioxide (CO2), salt water, and
higher operating temperatures aggravate internal pipe corrosion. Corrosion-resis-
tant alloys, inhibitors, and linings provide solutions for internal corrosion problems.
FBEs have been formulated to operate in these very harsh service environ