Girth Weld Protection on HDD Bore Pipe

A new pipeline construction project in Oklahoma required a horizontal directionally drilled (HDD) bore to permit pipe installation under a creek bed. In such situations, girth welds associated with the field assembly of the pipeline must be coated and protected from mechanical damage through interactions with roller cradles and rocks/aggregate within the bore.

Girth welds and the adjacent cutbacks on the bore pipe are typically coated with a two-part epoxy.  In this instance, the midstream asset owner was concerned about damaging the two-part epoxy and selected InduMar’s Boreshield^TM ARO II, a heavy-duty fiberglass-urethane composite, for additional protection.  For each of the ten cutbacks of the 400’ section of 10” OD bore pipe to be pulled, Boreshield^TM ARO II was applied according to a wrap plan provided by InduMar.  The plan called for the installation of a single roll of the 12” x 30’ composite wrap per girth weld to provide for a straightforward, repeatable, and efficient installation.

Boreshield^TM ARO II composite wrap, consisting of an abrasion resistant fiberglass fabric pre-impregnated with a water-activated urethane, was installed in minutes to produce 28” of coverage over the weld seams and adjacent cutbacks, with a 6-ply (0.33” thick) protective wrap over the girth weld. The approach was also repeated for a section near the pull head to assess the durability of the protective wrap subjected to the specific pull and bore hole conditions.  Although marring and gouging of the neighboring regions of pipe and of the composite wrap were detected following the pull, Boreshield^TM ARO II exhibited excellent adhesion to the pipe, complete cohesion of wrapped layers, and successfully protected the underlying epoxy coating from abrasion.  By sacrificially absorbing the impact and gouge energy experienced during the pull, the easy to install composite wrap provides protection to the underlying epoxy coating installed on the susceptible cutback and girth weld region