High performance Coatings for Horizontal Directional Drilling (HDD)
Trenchless laying of transport lines was originated in the USA in the 1980ies and has spread over the globe within short time. The hereby used equipment has experienced tremendous developments so that sections of more than 2.000 meter and pipe diameters up to 56” can be laid in a horizontal directional drilling (procedure). The requirements onto factory -and field applied coatings have been raised significantly. The coatings have to withstand enormous abrasion and shear forces. The suitability of coating material used in the field has to be proved carefully for this challenging operation. Applications faults or inappropriate material selection will cause tremendous damages and subsequently high rehabilitation costs. DENSOLID®-HDD was especially designed for horizontal directional drilling projects. Its coating system is based on a 2-component polyurethane formulation which is secure to apply by injecting the compound into a translucent casing sheet. The system complies with the highest standards of EN 10290 Class B Type 3 suited for permanent operating temperatures up to +80°C ( +176°F). Mixing faults will be avoided by injecting the material out of a two-chamber cartridge and mixing the two components thoroughly with a static mixer. During the curing process the coating material must be protected from water, contamination and moisture. These requirements are perfectly fulfilled by using a casing sheet in which the coating will be protected during the curing period. After curing the material shows an excellent shear- and abrasive resistance combined with an extraordinary flexibility. This proven system now has been developed to a new stage so that the flow of the material could be optimized to reduce the application time for more than 30%! In this presentation we will highlight the positive experiences made on two current HDD projects in Israel and Russia on 36” and 56” pipelines.