Press Releases
November 2008
Syntho-Glass® XT Undergoes 3rd Party Testing
Stress Engineering Services, Inc. (SES) conducted third party testing to evaluate our Syntho-Glass® XT composite repair system. The evaluation involved conducting a burst test and a pressure cycle fatigue test on repaired 12.75-inch x 0.375-inch, Grade X42 pipe having simulated corrosion with 75% wall loss. Strain gages were applied to the pipe in the corroded region under the repairs to evaluate the level reinforcement provided by our composite materials.
Below are excerpts from Stress Engineering Services, Inc's test "Experimental Evaluation of the Neptune Syntho-Glass® XT Composite Repair System, SES PN 118079CRA" dated November 2008:
"In summary the following observations are made when reviewing the results from the testing of the NRI Syntho-Glass® XT composite repair system:
- Burst pressure was near the theoretical value for the base pipe based on the MTR-based ultimate tensile strength for a non-corroded pipe condition.
- The presence of the composite reinforcement significantly reduces hoop strain in the corroded region. Had the composite material not been present, the burst pressure would have been on the order of 1,100 psi, as opposed to the actual leak pressure of 4,254 psi.
- The presence of the composite reduces the stress in the corroded region to a sufficient level that permitted a leak before break condition occurred. Had the composite material not been present, a ductile overload failure would have resulted and opened the pipe up with the traditional fish-mouth burst failure pattern.
- The fatigue test results are significant in terms of the number of cycles achieved and the relatively low alternating strains recorded during testing.
- The results of the testing program, as reported herein to date, indicate that the NRI composite system effectively reinforces 75% corrosion in 12-inch NPS pipe both in terms of short term strength and fatigue life.
This report has provided technical details on the performance of the NRI Syntho-Glass® XT composite repair system in reinforcing a 12.75-inch x 0.375-inch, Grade X42 pipe sample with 75% corrosion. The experimental evaluation involved full-scale burst testing and cyclic pressure fatigue testing to failure. Strain gages were installed in the corroded region beneath the composite repairs in both test samples.
The burst test sample failed at a pressure of 4,254 psi (1.72 times SMYS), while the fatigue sample that was cycled at 36% SMYS (900 - 1,800 psi or 50% MAOP) failed after 165,127 cycles. From an applications standpoint, this number of pressure cycles corresponds conservatively to a design condition of 25 years for a moderately aggressive condition in a high pressure gas transmission pipeline, and 64 years for a light pressure cycle condition.
It should be noted that the geometry of the simulated corrosion evaluated in this study is aggressive in terms of both its area and depth. Typical external corrosion in a pipeline is not uniform and the associated pitting results in an uneven wall loss pattern. Therefore, the 8-inch x 6-inch simulated corrosion incorporated into both tests is an upper bound on what one would expect in an actual corroded pipeline. Additionally, the estimated years of service are conservative in that the cycles to failure have been divided by 20, resulting in a lower bound estimate of the actual estimated years of service."
Complete document available upon request.
About Neptune Research, Inc.
Since its founding in 1982, Neptune Research Inc. has been engaged in the development, manufacture and marketing of a patented resin impregnated fiberglass cloth which provides an effective, time and cost efficient solution for the repair and corrosion protection of pipes, pipelines, pilings and similar structures. Our products are used globally and serve a broad range of markets including industrial, marine, oil and gas, municipalities, mining and utilities.
