Coating Application

In 1992, we partnered with L.B. Foster Company to provide line pipe coating on-site. L.B. Foster brings almost 100 years experience in the manufacturing, fabrication, and distribution of products serving the nation’s infrastructure. The Foster Coating Division is an industry leader in the application of corrosion-protection coatings and — like American Steel Pipe — is ISO-9002 certified.

COATING PRODUCTION
L.B. Foster applies fusion-bonded epoxy coatings, providing the ultimate in corrosion protection to steel pipelines. Other products offered to the pipeline industry include dual powder coatings for abrasive resistance; externally applied urethanes for abrasive resistance; and internal liquid epoxies for increased flow efficiencies.

Pipe is transported by an internal rail system from the American Steel Pipe mill to L.B. Foster’s coating facility.
Pipe is pre-heated above the dew point, blast-cleaned with steel shot and grit to ensure a proper cleaning, and inspected for any remaining surface irregularities on the cleaned surface. Detrimental steel irregularities are removed.
Pipe is pre-heated to powder manufacturer’s recommended temperature range.
Electrostatic guns spray the epoxy powder over the heated surface, at which time the powder flows, gels, and cures to create a superior bond between the epoxy and the steel.
Once set, the coating is water-cooled to a handling temperature of less than 200° F.
Each joint is stenciled to provide complete traceability.
The coating is inspected on every joint with an electrical holiday detector. If any holiday is found, it is patched immediately and re-inspected. Proper coating thickness also is verified.

QUALITY CONTROLS
L.B. Foster conducts several control tests and procedures on the epoxy resin and pipe throughout the coating process.

Pre-Application Powder Analysis
Each batch of powder is analyzed in the lab prior to application.
Bend Test
A test specimen is chilled in a freezer, removed, and then placed in a hydraulic mandrel bender or four-point bending apparatus to determine the coating flexibility.
Porosity Rating and Interfacial Contamination Test
Coating is removed at a low temperature and a sample is evaluated for cross-sectional and interfacial porosity along with interfacial contamination.
Cathodic Disbondment Test
An intentional holiday is made in a coated panel and evaluated for resistance to cathodic disbondment.
Water Permeation Test
A sample is submerged in water at an elevated temperature for 24 to 48 hours to evaluate coatings adhesion.
DSC (Differential Scanning Calorimeter)
Testing on incoming powder and the applied powder is available.

For specific coating specifications from L.B. Foster, visit http://www.lbfoster.com/coatedproducts/ or contact your American Steel Pipe sales representative.