10012 New developments of Mid-Tg-FBE Powder Coatings to meet the requirements of pipe coaters and pipeline owners

Tuesday, March 16, 2010: 8:30 AM
207 A/B (Henry B. Gonzales Convention Center)
Volker Dr. Börschel*
Akzo Nobel Powder Coatings
NEW DEVELOPMENTS OF MID-Tg FBE POWDER COATINGS TO MEET THE REQUIREMENTS OF
PIPE COATERS AND PIPELINE OWNERS
Abstract
The development of oil and gas fields at increasing depths in recent years, both onshore and offshore, and the need for pipelines to carry viscous media such as oil sands at high temperature to improve flow efficiency, has created a requirement for the coatings used to protect such pipelines from corrosion to be able to operate in a temperature range 120-150oC. One of the most successful coating types for the corrosion protection of steel pipes is Fusion Bonded Epoxy (FBE) powder coatings but, until now, the range of options available for pipelines operating at high temperatures has been mainly limited to either a standard FBE applied at a higher film thickness or as a dual-layer system, or an FBE with a higher film Tg applied as a primer for a 3-layer polypropylene system.  
Whilst it is widely accepted that it is preferable for the Tg of the coating film to be at least 10oC above the operating temperature of the pipeline there are few FBE coatings commercially available with a film Tg in the range 130-160oC . The few that do exist have relatively limited flexibility particularly at low temperatures which limits the range of environmental conditions that pipelines coated with such products can withstand.
This paper presents the development of a range of mid-Tg FBE powder coatings with film Tg’s in the range of 120-150oC and test methods with conclusions.  These coatings demonstrate excellent adhesion and mechanical performance, even at temperatures down to -60oC, thus greatly expanding the range of field conditions and pipeline operating temperatures that can be accommodated.  The excellent flexibility of these coatings enable them to be applied as a single-layer FBE coating, and as a dual-layer FBE coating system, as well as a primer for 3-layer polypropylene systems.