Fire Resistant Pipe

Topic #: N2000-040
Sponsor: NAVSEA
Status: Phase II Completed.
Need: Easy installation/removal of pipe couplings.
Gap: Inaccessible bolts on current couplings make process labor intensive.
Requirement: MIL-STD-777E.

Conventional flange-type pipe couplings used aboard U.S. Navy surface ships and submarines typically have a large number of axially oriented bolts located around the circumference of the flange. The installation of conventional pipe couplings requires equal access to all of the bolts to ensure evenly torqued joints. The large number of bolts and accessibility difficulties with conventional pipe couplings results in a labor-intensive process for the removal and installation of these couplings. Nearby structures and equipment often have to be removed and reinstalled to gain access to the hidden bolts, or joints are inadequately tightened in cases where removal of nearby structures is not feasible. Texas Research Institute Austin, Inc. developed a low cost, lightweight, fire-resistant, easily accessible composite pipe coupling that meets the requirements of MIL-STD-777E. The use of composite materials will reduce the cost and weight of the coupling while providing a reliable, fire-resistant, corrosion-free service life in excess of 15 years.