History of Epoxy Barrier Coatings in North America

History of Epoxy Barrier Coatings in North America

Cost-effectiveness, non-disruptive and sustainability are all key contents when considering how to fix damaged or failing pipe systems. In addition, downtime, resident displacement and reconstruction are added concerns during the planning process. The cost to fix the damaged pipes can be astronomical, especially when the pipes are under tiled floor or behind painted walls.

Pipe systems are often forgotten about until there is a problem, however there are technologies available that can be used as a preventative measure against pipe failure. These same technologies are used time and time again when there is already a problem that needs to be addressed. Pinhole leaks, corrosion, low flow, root intrusion and infiltration are just some issues that building owners, property managers and engineers commonly run into.

Like all tangible objects, pipe systems age and need repairs, but the traditional process to dig up and replace pipes has more disadvantages than benefits. This is why many plumbing and mechanical companies are adding trenchless technologies to their toolbox. Pull-in-place structural liners and blown-in epoxy coatings are two, world-wide pipe lining technologies used to rehabilitate pipes without destruction meaning, less time, less mess and less reconstruction costs.

Trenchless pipe lining technologies are not new – some of the technologies have been used for decades, passing the test of time. For example, starting in the late 1980s, all of the U.S. Navy’s Aircraft Carriers’ collection, hold and transfer pipe systems have been lined with Nu Flow’s blown-in epoxy coating.

Established in 1987, American Pipe Lining Inc. began in San Diego, CA, where it worked with the U.S. Navy to develop and, later patent, epoxy lining technology to protect aircraft carriers, vessels and piping in government facilities.

American Pipe Lining and CEO Steve Mori developed equipment to meet the demands of each application that had differing conditions and environments so that an epoxy coating could be applied to the interior of the pipes in-place. This included maintaining pipes at required temperatures for optimal in-place cleaning and coating.

APL later expanded its lining solutions to include applications in the private and domestic piping markets that faced aging potable water systems and poor water quality.

In 2007, the APL was acquired by Nu Flow Technologies and today this technology is still being used and licensed worldwide to rehabilitate residential, commercial, industrial, federal and municipal properties.

Epoxy coating restoration of pipe systems is a non-invasive process that uses epoxy to coat the inside walls of pipes without destruction to interior or exterior surfaces of building structures, hardscape or landscape. Epoxy coating is used not only as a long-term solution to prevent corrosion and leaks, but is commonly used as a preventative tool to extend the life of existing piping systems. It is regularly used in pipes ½” to 12” in diameter. The second technology, structural lining, creates a structurally sound pipe within the system without removing the existing pipes.

It is easy to see the importance of updating pipe systems, but it is also important to keep the proper perspective on what the results are. Old drainpipes are getting rehabilitated back to a usable pipe, the pipes are being recycled without removing them and creating landfills full of construction waste. Lining companies want to provide cost-effective solutions to owners of buildings and homes, while property owners and managers want a cost-effective way to solve their slowly failing infrastructure without destroying the building in the process.

Most facilities built prior to the 1970s have sewer lines composed of cast iron and clay. The most common problem found with these lines is cracking at the joints, root intrusion and the bottom of the pipe rusting out; this can ultimately be a result or lead to root intrusion. Root intrusion in sewer pipe systems is reported to cause 50% of all sewer blockages. Traditional care for root intrusion is rarely a long-term fix. With the pipe lining method, roots can be removed and a liner can be pulled into place, creating a structurally sound pipe within the existing pipe. Other common problems include calcification in sewer lines and ground movement. Millions of linear feet of drain and lines have been saved using the pull-in-place structural lining process.

It is easy to understand why the most effective and growing solution for failing pipe systems both inside and outside of buildings is pipe lining technology. Liners are installed inside the pipe systems without destruction and can protect the pipes from many types of common failures, including debris build-up, corrosion, leaks and root intrusion. Most importantly, pipe liners protect the carried contents from mixing with the metals within the pipes, which can result in decomposition or lead leaching into drinking water. Not only are potable water lines and drain lines being rehabilitated, but the same technologies are used to retrofit vertical applications, roof drains and mechanical systems, including fire suppression and HVAC systems.

Pipe lining technology requires no digging or destruction and is the most

effective, long-term solution for failing pipe systems located both inside and outside of buildings. Pipe lining is the optimal solution to increase flow, eliminate root Intrusion and prevent leaks. It can hold up to the structural strength of a new pipe, without the costly digging and replacement repairs.

The structural lining project begins with mapping the internal plumbing system and camera inspection of drain and sewer lines. A plan is implemented to minimize disruption and afford the most efficient timeline for work completion. Depending on the lining method to be used, pipes may be drained and/or air-dried. After testing for leaks, the pipes are prepared for cleaning.

The next step involves removing roots and calcite in order to return the pipe to its original functioning diameter. Removal methods may include jetting the lines or the use of pneumatic tools such as a scorpion cutter. Cast pipe may require additional preparation if there is significant corrosion or missing sections of pipe.

Existing access points are used to pull an epoxy-saturated felt liner into the host pipe. This lining method provides the ability to line multiple 45° and 90° angles, as well as the option of lining specific sections of pipe without lining the entire length. Once complete, a final leak test and camera inspection is performed and the system is now a smooth, jointless pipe within the existing host pipe.

Case Study

A 1985 condominium complex was in dire need of pipe rehabilitation. The residents do the luxurious Triple Crown Condominiums, located near the beach consisted of 190 units with 18 separate buildings.

The pipe system consisted of hot and cold potable water lines that ranged from half an inch to one inch in diameter. They were located in the walls and under the concrete below all the units. A dilemma emerged when residents had experienced an influx of slab leaks. Seeing this as an issue, both the residents and insurance companies became concerned and started to seek long-term solutions – not only to fix current leaks but to also prevent future leaks as well. Looking at their options, the Triple Crown HOA could go with a re-route, dry-out, and slab repair that could end up costing them $10,000 almost costing them $200,000 for the whole project. Looking for a more cost effective and non-disruptive solution HOA chose Nu Flow.

The simple yet highly effective epoxy coating process begins with inspection to determine the problematic areas and pipe dimensions. A plan is implemented to minimize disruption and afford the most efficient timeline for work completion. The piping system is inspected for integrity and spot repairs are made to excessively worn joints and fittings. Temporary bypass water piping may be installed. The system is drained and air-dried. After testing for leaks, the pipes are prepared for cleaning.

Pipes are dried with heated, compressed air and a safe abrading agent is blown through the pipe system, removing rust and corrosion by-products that are collected in a holding unit for disposal. Compressed air is applied once again to remove fine particles.

The epoxy coating is applied to the pipes by using conditioned air to uniformly distribute the epoxy throughout the pipe segment. Following the coating application, continuous controlled air flows through the pipe to facilitate epoxy curing. When the epoxy cures, valves and couplings are refitted and a final leak test and inspection confirms the integrity of the line. Water quality, volume and flow tests can confirm the functionality of the system.


With alternatives to traditional pipe replacement available, it is no wonder that many homeowners, property managers and municipalities are turning to trenchless pipe lining to rehabilitate their pipe systems. This is also why so many plumbing and mechanical companies are adopting pull-in-place structural liners and blown-in epoxy coating technologies and offering them to their own clients.



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