A Pipe Within A Pipe
Contractor Steve Feltner runs Feltner's Sewer & Drain, Milwaukee, and as the name suggests, the family-owned business specializes in piping that lies under grass, dirt, cement, tile, etc. You name it, and if piping is under there, Feltner will repair it.
Feltner was recently called in to repair a drain line under the kitchen floor of a hospital. Not that long ago, about the only way to conduct such repairs was to rip up whatever was covering the line before you could literally get to the problem. That usually meant a headache for the sewer and drain line owner, to say nothing of the other aches and pains associated with the “reconstruction” costs of putting everything back in place.
Yes, the hospital could have shut down the kitchen and arranged catering for the patients' meals while ripping up the floor and conducting line repairs. But what about the risk of contamination? Or controlling dust and other irritants that would be sure to enter the ventilation system? Did Feltner have a different way?
As it turned out, Feltner did adopt a different way last October. In this case, he used a pipe relining product, a relatively new breed of trenchless alternatives that are proving to be cost-effective and certainly the least disruptive way for making underground piping repairs.
“It helps to be part plumber, part chemist,” Feltner says about the liner from Perma-Liner, Largo, Fla. We may be oversimplifying, but the Perma-Liner system is an “air-inversion” technique for fixing damaged underground pipe. The liner material is impregnated with a special blend of resin and inverted into the existing underground pipe using low air pressure. Once in place, the curing process takes three hours, and the liner cures as a new, structurally seamless, jointless pipe, with a life expectancy of 50 years, inside the original pipe.
“You can't put new pipe in the ground and expect it to last any longer,” Feltner adds.
Perma-Liner is just one of an array of products currently being marketed to contractors. For the most part, these techniques, particularly for lateral sewer line rehab, are scaled-down versions of the same procedures used for repairing sewer mainlines. Complete rehab work includes:
- Cured-in-Place Pipe (CIPP)
- Fold-and-Form Pipe
It's also safe to say that most of these products fall into the growing “not from around here” category of plumbing, piping and heating products born in Europe and/or Japan that are gaining headway in the United States.
MaxLiner, Morrisville, N.C., for example, is a CIPP lining system originally developed in Switzerland specifically for laterals. While widely used to Europe, it's only been available in the United States since 2000.
While certainly each company is bound to make its own competitive claim, when everything is said and done, we're talking about a process that creates a “pipe within a pipe” in ways that leave the repairs stronger and with a warranty that's longer than putting new pipe in the ground.
Perma-Liner and MaxLiner are both early American pioneers for the CIPP method. PM first wrote about these types of lining procedures last year when we talked about the need to reduce infiltration and inflow or “I/I.” The notion still bears repeating since both makers pointedout that lateral lines are still a tremendous market for repairs.
Essentially, too much water, either groundwater or rainwater, seeps into cracked lateral lines. That ends up turning into a flood when the water reaches a municipal water treatment plant. Since the plant can't handle the inflow, it may have to dump untreated sewage into lakes and rivers.
“The EPA has mandated that cities do something about failing sewer systems,” says Jerry D'Hulster, president of Perma-Liner. “Even though a city has fixed its sewer lines for 25 years, its efforts are exhausted because the homeowners' private sewer laterals still need to be repaired.”
As underground infrastructure ages throughout the world, and engineers and contractors debate the installation and effectiveness of PVC, corrugated steel, concrete and other pipe materials.
“What's nice about CIPP products is that it can be used in any type of pipe,” D'Hulster says. “At the end of the day, you're getting a brand new line with the CIPP liner as you would with brand new pipe being laid in after excavation.”
The Only WayWe don't doubt that lateral line repairs may still be a promising market. But in talking with other contractors this year, sometimes the lining process is the only way to easily get the job done.
Here are the details of Feltner's repairs at the Aurora Medical Complex in Kenosha, Wis. The problem was a separated 4-inch PVC line running from under the kitchen floor to a grease trap on the outside of the building. This allowed backfilled gravel around the pipe to enter the line, causing debris and food scraps to easily form continual blockages - hardly a plus in any commercial kitchen, and a hospital kitchen made the problem all the worse.
Feltner and his crew had to come up with a solution to access the break. If they dug up the line on the outside, they couldn't shoot the line from that point due to a riser just inside the building. The next option was to break the floor. But as we mentioned, that meant dust control, catering meals for patients, tile replacement - at least two days downtime for the kitchen.
After viewing a video of the line, they knew the break was approximately 8 feet in. About the only “easy” access was a 4-inch cut out with another branch line tying in at the bottom.
They decided to try and shoot the liner with a technique called “shooting a tear away.” This allowed the team to shoot the liner right through the clean out without so much as a cracked tile.
They worked after hours and did not interrupt kitchen operations in any way. Basically, the work began at 8 p.m. on a Friday and, by 6 a.m. Saturday, the kitchen was back in business and ready for breakfast.
Finishing TouchesFor a repair on a grander scale, take a look at what was discovered as the finishing touches were pretty much completed for a sports complex built on the campus of California State University.
Contractors installing flagpoles around the tennis center drilled too deep, leaving a gaping hole 39 inches wide in the facility's 8-inch sewer lines, just two weeks away from opening day. The problem was only detected after Long Beach Roto-Rooter was hired to clean the sewer line of leftover construction debris.
The severed sewer line was buried 36-feet deep below slabs of concrete, thus ruling out excavation. Spot repair? Maybe, but there was no way to dig an access hole and safely send a man 36 feet down.
The Roto-Rooter team explained the situation with MaxLiner. The pipe, at first, seemed unreachable. The closest access to the break was 28 feet away. To use the MaxLiner CIPP repair method, they needed to find a way to bridge the gap in the break and shoot the new liner approximately 6 feet beyond the break to reach the host pipe.
Instead of drilling approximately 36 feet from the surface, Roto-Rooter went into the subterranean area where the maintenance shop is located and dug an 8-ft. by 8-ft. access pit. This provided an access point just 11 feet away from the point where the pipe was broken, shaving 25 feet off of the excavation.
Before they could determine if CIPP relining was feasible, they had to create a path from entry point A (inside the maintenance shop) to entry point B (where the line was already exposed). First, they cleaned the line to get a clear shot. Next, they pulled a preliner all the way across the break and connected the two sections of the severed pipes. This preliner created a path for the new CIPP liner to travel to reline pipe. The preliner, acting as a conduit, formed a collapsible pipe and bridged the gap between the broken pieces.
Eventually, when Roto-Rooter inverted MaxLiner's liner, the team overshot the preliner by 4 feet so the liner could adhere directly to the PVC host pipe. Using MaxLiner's calibration hose to inflate the liner, the team let it cure for 24 hours prior to pulling out the calibration hose. The entire process was monitored by video to ensure quality.
From discovery of the break to the completion of the repair, the job was completed in four days.
Renovating Corroded Pipe From The InsideSmashing through wallpaper, tile, drywall, wood floors and ceilings to repipe corroded domestic water pipe may make even more of a mess than ripping up the front yard to expose a damaged lateral line. At the very least, the lateral is outside.
And repiping income-producing property, such as a hotel, typically means shutting off entire sections of a building, not to mention the inconvenience to staff and guests in other parts of the facility.
ACE Duraflo Systems, Placentia, Calif., and Curaflo Technologies, Vancouver, Canada, are two emerging players offering an alternative to repiping with a procedure that coats the inside of existing corroded pipes while “in place” with a special barrier lining.
Here's how the process basically works: After shutting off the water supply, technicians connect special equipment to key access points in the water piping system and perform three primary steps. 1) Pipes are drained, heated and air-dried. 2) Then the insides of the pipes are cleaned using special corundum to remove any scaling or corrosion of the metal. 3) Finally, a proprietary epoxy is dispersed throughout the plumbing pipes, under pressure, to form the protective barrier coating. The coating completely seals the pipe, joints and fitting surfaces.
“If you were to look for an example of where you would find a similar coating in everyday life,” says Sam Chan, director of market development, Curaflo, “just look inside a soup can and you will see a thin, glossy lining protecting the food contents from the material makeup of the tin can. That thin coating is epoxy.”
The coating helps prevent a major cause of water damage and mold formation in homes today - pinhole leaks in corroding copper, lead or galvanized steel piping.
Both companies' coatings are NSF/ANSI-approved.
“We do soak tests with the epoxy exposed to water conditions that are far more aggressive than what one would ever find in potable water supplies,” says Bruce Mayo, vice president of marketing, ACE DuraFlo.
While the exact cause of “aggressive” water is still the subject of debate, lead is one result that has been in the spotlight after Washington, D.C., water officials announced an alarming increase in the lead levels of tap water.
“A major theory as to why lead is showing up now involves an Environmental Protection Agency requirement that water districts must remove natural organic material from drinking water, which makes the water itself more corrosive to pipes,” explains Larry Gillanders, CEO ACE DuraFlo.
A difference of just one pH unit may not sound like a lot. But given the mathematical complexity behind the commonly used measurement, a difference of one pH unit represents a tenfold change in corrosiveness.
In copper pipe systems, when the pH is more than 8, a copper oxide film usually forms on the pipe walls. The film acts as a barrier that slows the effects of corrosion. However, when the pH in the water supply is lower than 8, the copper oxide film is dissolved, which leaves no protective barrier from the corrosiveness of the water streaming through morning, noon and night.
“The epoxy barrier coating is putting on the pipe something that Mother Nature had done before,” Mayo adds.
Gillanders is quick to point out that his coating can't do anything about the lead in water as it enters anyone's property.
“We can protect the internal piping system from corroding or leaching metals,” he adds. “This process doesn't remove the lead from the water, but it seals any lead pipes, lead solder or copper behind the epoxy barrier coating so that water-to-metal contact is eliminated.”