CIP technology is taking its next evolutionary step with the introduction of LED-cured liners.

LED curing has many of the advantages found with UV curing, plus the additional benefit of a single light head. This allows the systems to cure in pipes as small as 4 inches and gives it the ability to cure through tight bends.

Unlike hot-water or steam curing, LED systems don’t require large equipment and can perform indoors with minimal disruption. Using a specific light-reactive resin, wet-out liners are stable enough for storage and extended working times.

“This technology is the next step in innovation for lateral lining, and CIP in general,” says Matt Gabrielse, product manager for HammerHead Trenchless, which recently became the U.S. distributor for Bluelight LED-curing systems. “It’s going to become the new standard, we believe, for CIPP.”

Tried and tested in the European market for about eight years, LED-curing technology is now making its leap across the pond.

“We’ve seen quite a bit of activity there. Europe is typically a few years ahead of us domestically,” Gabrielse says.

LED systems cannot currently be used for potable waterlines, but Gabrielse says Per Aarsleff, owner of Bluelight Technology, and HammerHead Trenchless plan to further develop the system for more diverse applications.

“This system itself is designed for the lateral CIP market, so sanitary sewers, storm sewers and other gravity-fed pipes are all great applications for this product,” he says.

How it works

All that’s required to run LED systems like Bluelight is the light train, power supply and module, control unit, air supply, and inversion drum. Bluelight, like LED UV curing systems, utilizes an inversion method to install the liners, and airflow used to cool the light head also serves to maintain pressure on the liner as it cures. However, Bluelight uses a resin that only reacts to a light range of 450 nanometers, which makes it a very stable resin and allows for the extended storage and working times.

The compact light head, unlike the segmented train of a UV system, makes LED systems incredibly versatile. They can be used with a variety of liners, including glass fiber or felt, and provide the ability to navigate 90-degree bends. They can even work through changing pipe diameters.

“The light head we use is much more compact than a UV light would be,” Gabrielse says. “UV light trains are usually very long and cumbersome, whereas this LED light head is small and compact and can work really well for the lateral market.”

The Bluelight system uses a touch-screen control panel to manage the mostly automated process. A monitoring program will send the operator alerts if issues occur in the pipe.

“The system is similar in size to a pushrod camera system,” says James Stern, director of Bluelight’s U.K. distributor, PBF Drainage Services. “Due to the nature of lining, there are always inherent risks during the installation process. Because the entire Bluelight process is monitored by using an internal camera system, any defects can be seen prior to curing, and these can be rectified before any problems arise.”

Because resins for LED curing are not heat- or ambient-cured and only react to light, liners are typically wet-out in advance away from the job site. Doing so in a controlled facility limits environmental and site impact.

“With this sort of technology, you have a small footprint,” Gabrielse says. “You’re not dealing with water, so that alone is a huge benefit. You don’t have a heavy water boiler or steam unit to tote around, and you don’t need an area to dispose of the water when you’re done curing.

“When you’re using a hot-water boiler or steam machine, much of the equipment is required to be outdoors because of the exhaust and fumes it creates,” he says. “This process can be done completely inside.”

The noise of the air compressor can cause minor disruptions in close quarters, but it is negligible in comparison to alternative methods.

“The actual curing process itself is much faster than when you compare it to traditional hot-water or steam methods,” Gabrielse says. “It depends on the length of pipe, but LED-curing technology can be up to five times faster than conventional curing methods.”

Gabrielse says both the faster curing and pre-wet capabilities make this system much less stressful on operators. “When you compare the LED technology to all of those other options, as soon as you mix the resin and put it in the liner, the clock is ticking. So you have a certain amount of time to get that liner from wet-out to actually getting it in the pipe and curing. It can’t just sit for an extended period. With LED technology, you don’t have that issue. It allows the contractor or customer to avoid mistakes by not battling the clock.”

A promising solution

With something as complex as CIPP, there may never be a perfect solution that can fit every situation, but LED-curing systems provide contractors with an adaptable option that is certain to become a staple of the industry, especially in challenging small-diameter laterals.

“We are always striving to use the most cost-effective and environmentally friendly method available, making sure the correct liner is installed for that particular situation,” Stern says. “Not every liner is suitable for all situations, and the Bluelight system increases our capabilities.”

The Bluelight system’s efficacy and speed were tested when PBF Drainage Services’ customer successfully installed dozens of liners in a university setting. With zero odors per the client’s request, they completed all work on a tight schedule during holiday breaks with no site impact.

“LED technology is really cutting-edge. It can be used in any type of pipe that a regular CIP liner could be used for gravity applications,” Gabrielse says. “It allows the customer to be a lot more versatile all-around and plan out their jobs far in advance without fighting the clock.”