This paper describes an advanced 100% solids rigid (or structural) polyurethane technology, for field applied coating of pipeline girth welded joints and pipeline rehabilitation, for oil/gas and water/wastewater transmission lines. This technology applies either a castable type resin or a sprayable resin in the field, and allows for encapsulating or coating of steel pipeline joints, or sections, in minutes under a wide variety of conditions. The key technical parameters and requirements associated with the technology for such field coating application are discussed. The lab and field-testing results of the 100% solids structural polyurethane coating technology and case histories are reviewed, including its compatibility with polyurethane, polyethylene, polypropylene and fusion bond epoxy coated pipe operating at standard or elevated temperatures. Comparisons with some other typical liquid-applied field coatings for pipeline girth welded joints and pipeline rehabilitation are also discussed, including coal tar epoxy, 100% solids epoxy, 100% solids elastomeric polyurethane and with fusion bonded epoxy as a reference.
Keywords: 100% solids coating, rigid polyurethane, structural polyurethane, pipeline, girth welded joints, field applied coating, rehabilitation.