To ensure the secure supply of drinking water and the efficient removal of sewerage, existing infrastructure must be replaced with more modern and resilient pipes. However, installing new pipes using conventional open cut technology could be an extremely costly option, requiring a huge allocation of funds and manpower, and causing significant disruption to residents and business.

By contrast, relining can be a cost-effective, time-efficient and non-disruptive means to rehabilitate existing underground infrastructure. As demand for relining solutions increases, numerous companies are developing innovative tools and techniques to make this procedure even more effective. Here, we preview some of the latest products on offer from leading relining firms.

Brandenburger

Brandenburger currently offers UV light-curing GFRP liners, with circular profiles of DN 150–1,000 and egg-shaped profiles of 200/300–800/1200. These have wall thickness of 3.5–9.8 mm (UV light-curing), while larger wall thickness are also available with combination curing (light and heat). The liners come in lengths of up to 300 m. The company also offers BlueTec UV light-curing equipment, with different types available to meet various construction site requirements, including comfort, portability, and compactness.

In addition, Brandenburger has also recently released the BBplus liner, which features a smoother and more homogenous surface than conventional liners. This creates a reduced contact surface for the sewage flowing through, meaning that the liner becomes more resistant and long-lasting. Although the BBplus liner is installed under greater pressure than most liners, it still uses the same easy and conventional handling techniques.

In the future, Brandenburger aims to produce liners that are even more efficient to install. A company representative said “The key issues in future liner developments will be to make relining products still easier to handle and install, to simplify processes and make them more secure.”

Reline America

Reline America is the exclusive North American manufacturer of the Blue-Tek and more abrasive resistant Blue-Tek/AR3 UV GRP-CIPP liners. “These fibreglass technologies have a product life of more than 50 years and offer simple, cost-effective installation,” said the company. The seamless, spirally-wound liners are environmentally safe and have a six-month, non-refrigerated shelf-life.

The company also produces Quality-Tracker System installation equipment, and operates an on-site research and development department to constantly develop new trenchless pipe rehabilitation products.

Perma-Liner Industries

Perma-Liner is another firm at the forefront of CIPP technology. It produces a resin that is 100 per cent solids epoxy, with no shrinkage to allow annular space between the host pipe and the new liner, eliminating the chance of roots infiltrating the sewer system. This epoxy resin has a cure time of three hours without using external heat sources.

The liner and resin supplied by Perma-Liner has been shown to exceed the standards of ASTM F-1216-07b CIPP installation and physical property requirements, which specify a minimum lifespan of 50 years.

Aqua-Pipe

Aqua-Pipe is a standalone structural liner that can withstand loads and internal pressures without assistance from the residual strength of the existing pipe.

Aqua-Pipe is made of two circular woven polyester jackets with a watertight polymeric membrane fused to the inner jacket, and can be used to structurally rehabilitate all types of water mains 6–12 inches in diameter. The liner is pulled in place and cured by circulating hot water.

The proprietary epoxy resin has no effect on water and contains no styrene. Cast iron and ductile iron water mains are the most common pipe materials which have been rehabilitated to date, but other material types, including asbestos cement, steel, PVC and concrete, can also be rehabilitated if required.

Sekisui Rib Loc

A project using the Sekisui Rib Loc system has produced the world’s largest spirally-wound pipe, weighing in at almost 100 tonnes. Interflow installed the 633 m long liner, 2.4 m in diameter, within a concrete sewer pipe travelling underneath the suburbs of Sydney, Australia. The project was completed by producing an in-situ pipe by spirally winding a composite plastic strip at a fixed diameter within the host pipe – in live flow.

This world-record project has now been selected for display at Sydney’s premier science museum, The Powerhouse, where visitors can learn more about relining technology via a video presentation, animation and interactive model.

“We hope that some of the 500,000 visitors that enter the museum each year will be interested by this example of a trenchless solution to a public infrastructure project. Hopefully this exposure will be beneficial for our industry,” said Interflow Director of Products and Technical Services Ian Bateman.

Aarsleff Pipe Technologies

Aarsleff Pipe Technologies manufacture and install CIPP linings with felt liners of dimensions up to DN 2,200 mm. In addition, they install glass reinforced liners of dimensions up to DN 1,200 mm, and manufacture glass reinforced pipes for slip lining in dimensions up to DN 3,000 mm.

Since the beginning of 2009, Aarsleff Pipe Technologies has begun curing Aarsleff CIPP Lining using LED light. A company representative said, “For years, light has been applied for many different types of curing processes. However, early on in the development process, we decided to develop an entirely new generation of light that would be more energy-saving and more efficient compared to existing types of light. The result was LED.”

The diodes applied in this method are highly efficient, meaning that curing occurs quite quickly, creating environmental and economic benefits. In addition, the equipment involved occupies little space, allowing the renewal of pipes even under very poor access conditions.

At present, Aarsleff Pipe Technologies has three complete LED units, and in the future intends to further develop its LED curing system. The company will also focus upon improving the optimisation of glass reinforced CIPP linings cured with UV light.