Breaking Ground in Brunei
Insituform Technologies, Inc. is constantly striving to expand its portfolio of solutions for pipelines around the world. One way it accomplishes this is to leverage its technology and experienced personnel to tackle complicated projects across the globe. In one recent project, Insituform was able to provide proven technology from North America and implement it in Southeast Asia. In turn, the experience on the project gave Insituform crews added knowledge and skill it could put into practice back home.
For the project, Insituform and its global partners used its composite pipe rehabilitation product, known as iPlus® Composite, to undertake the project. Already widely used in pipeline rehabilitation projects in the Western Hemisphere, the cured-in-place pipe (CIPP) product has been implemented in several areas in the Asia-Pacific region, including India and Australia.
The existing corrugated metal pipe, running beneath the Muara-Tutong Highway, was corroded and leaking throughout. Since it is considered a major highway, the Public Works Department Ministry of Development in Brunei Darussalam determined that a nondisruptive solution necessary to prevent possible sinkholes. The total project consisted of 4 separate installation shots. Two were 250-ft. shots with a diameter of 66 inches and 2 more shots of 300-ft. each with a 70-inch diameter. Insituform’s Hong Kong operations partnered with VSL Brunei to tackle the project.
The team chose composite CIPP reinforced with carbon and/or glass fibers in order to increase the strength of the cured pipe while decreasing the thickness of the finished product. This allowed for greater flow capacity and a reduction in the amount of resin that is used in the large-diameter pipe. This composite-reinforced tubing has proven to be a practical solution for the rehabilitation of medium- to large-diameter pipes, including those that are irregularly shaped, all over the world.
Improved physical properties of fiber-reinforced composites applied to cured-in-place pipe reduce the wall thickness required to withstand a given set of loads. This translates into a thinner product that weighs less for transport. In addition, thinner tubes reduce the difficulties associated with handling the dry tube during manufacturing. Since all equipment was shipped from Hong Kong to Brunei for the project, material weight was a big concern.
All support work was performed by VSL with CIPP installation work performed by Insituform’s Hong Kong operation. A project management and engineering support team from Insituform’s global resources provided top-notch assistance for the ground-breaking project.
Because daytime temperature reached 85° to 95°F, all work was performed at night. In addition, the large tube was wet out on-site in a temporary tent with resin and then sent down a protected grade to the installation site.
After the tube was pulled into place inside the existing pipe, it was inflated and cured using a steam-cure process, which was ideal due to the remote nature of the project. The steam-cure process can be beneficial for a number of reasons, especially when water is not readily available on the jobsite as steam-cure generally uses less than 5% of the water compared to a traditional water-cure process.
In addition to its water-saving benefits, the steam-cure process requires less time to cure and cool down, and cuts down on the amount of energy needed to heat the tube to cure temperature. For these reasons, it is considered a “green” alternative.
Challenging site conditions and rain every single night of the project made for difficult working conditions, but Insituform’s Hong Kong crew was able to successfully rehabilitate the first two sections of pipe in July. The two final sections are scheduled to be rehabilitated in September.
Participants in the project were happy with the results and agreed the project was a success. Eugene Zaltsman, Engineer for Insituform, said "We've done similar projects, but this was one of the most difficult of its kind. We gained a lot of valuable experience in Brunei that will help benefit future installations around the world."