Lifeguarding Hawaiian Pipelines with CIPP
The liner is “wet out” using a table designed to assure that the liner is uniformly impregnated with resin.
Adding Cured-in-place-pipe (CIPP) Technique has Carved a New Wave of Opportunities for a Plumbing Contractor
CuraFlo of Mesa, Arizona, is not only an expert in re-piping but in noninvasive pipe renovation, as well. In fact, CuraFlo is the sole distributor of its proprietary epoxy pipe rehabilitation technique for metallic water pipes, the CuraFlo Engineered Flow Lining System. It is an easily applied, permanent, in-situ epoxy lining solution for 1/2- to 4-in.-diameter metallic water supply pipes, including copper, galvanized steel, lead, cement or cast-iron supply pipes. The primary advantage of the system is the reduced need for structural demolition and restoration. In many cases the CuraFlo system requires no demolition at all.
Co-founder and CEO Brian LeMaire said the company had been passing up drainage system renovation jobs, leaving that part of a job to other specialists. Reducing the number of contractors a project owner or general contractor deals with is a welcome benefit to customers. A complex, complete interior pipe renovation job in Maui presented just such an opportunity.
The drainage job was for a condominium-style, time-share resort on Maui’s northwest coastline. Temperatures at the tropical island resort site remain warm year-round, ranging from the 80s and 90s in summer and mid-80s even in the coldest months of the winter. Continuous exposure to warm temperatures and humid, saltwater air, combined with saline ground conditions, had taken their toll on the resort’s 12,000-plus ft of 50-year-old cast iron drain pipes in its multiple structures. The pipes ranged in size from 1 ¼-in. internal drain pipes to its 12-in. exterior sanitary sewer main lines.
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The liner is loaded into the inversion gun.
Re-piping was not feasible for several reasons, mostly due to the lengthy time and high cost of demolition and restoration. While its epoxy system is an ideal solution for intact pipes, CuraFlo needed an equally competent, noninvasive and permanent solution for the resort’s sewer pipes, whose holes and cracks would require numerous point repairs before epoxy application.
CuraFlo turned to cured-in-place-pipe (CIPP) rehabilitation, choosing HammerHead Trenchless Equipment, a Charles Machine Works company, for its complete array of CIPP consumables and equipment and for its industry-leading customer support. Based in Lake Mills, Wisconsin, HammerHead Trenchless provides CIPP liners, resins and installation equipment for its customers. HammerHead is also an authorized distributor of Picote Smart Cutter pipe cleaning and lateral reinstatement systems. An additional selling point was HammerHead Trenchless’s customer support, which included guidance, supervision and consultation throughout the project. Teaming with HammerHead Equipment gave CuraFlo access to everything a company needed to complete a major CIPP job to the same high standards that have established CuraFlo’s reputation.
Like CuraFlo’s epoxy lining, the CIPP method is a quick, economical, noninvasive and permanent alternative to pipe replacement, sharing much in common with CuraFlo’s epoxy lining method. The nonstick CIPP lining creates smooth-flowing transitions that bridge wall irregularities, holes and cracks and through pipe bends and fittings from a single access point. And like epoxy lining, CIPP rehabilitations significantly improve flow rates, corrosion-resistance and intrusion-resistance. CIPP also improves pipe durability, adding 50 years or more to the expected service life of the existing pipe.
More Deteriorated than First Appeared
Both processes require a rigorous cleaning of a pipe’s interior surfaces prior to application in order to achieve optimum bonding. Cory Steckmann, a HammerHead Trenchless CIPP application and product line specialist onsite throughout this project, introduced CuraFlo to Picote drain cleaning products.
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First, the pipe to be rehabilitated was cleaned, measured, televised and recorded. Then it was cleaned using the Picote system, consisting of a rotary tool with flexible grinding panels that can be powered by a variety of rotary sources, including the company’s specifically designed, electric-powered “milling” unit, or Miller. Steckmann attached chain flails to the sheathed rotary cable to remove debris and scaling from the pipe. Then he fitted a hub to the cable with grinding panels to clean the pipe to fresh, corrosion-free metal for quality bonding.
The CIPP method was first used on straight 8-in. runs. After cleaning the pipes, the crew measured and cut HammerHead Scrim Liner to length. They mixed the two-part, styrene-free epoxy resin onsite just prior to the “wet out process.” Use of a purpose-made wet out table ensured the felt liner’s pores were uniformly impregnated with resin.
Wet out began by placing a vacuum pump at one end of the liner to eliminate air trapped within it. The resin components were measured, mixed, and poured into the end of the liner. When wet out was complete, the liner was spooled onto a reel inside the inversion drum. The free end of the lining was allowed to protrude through the drum nozzle.
Once the drum was locked shut, the protruding end of the lining was cuffed back over the nozzle and banded, sealing the drum. Charging the drum with air to 10 psi caused the lining to invert itself through the nozzle into the pipe, resin-side out. The resin was pressed uniformly along the pipe surface as the liner unfolded, creating a permanent, seamless rehabilitated interior pipe surface, smoothly transitioning through any point repairs.
Ambient Maui air conditions and the large diameter of the pipes called for a longer working window. HammerHead Trenchless’s summer hardener was selected for its longer working time, providing 50 minutes to an hour at 77 degrees. Cure time was two hours under this project’s conditions.
Lateral Reinstatement
Lateral ReinstatementCuraFlo’s epoxy lining system can be used through wyes and tees and pass fixtures without causing obstruction. Inverting liner through a wye or tee, however, temporarily seals off connecting laterals. The laterals must be reopened with lining cutter tools in a process called reinstatement.
The same dual-purpose Picote Smart Cutter system and Miller machine Steckmann had used for pipe preparation was used for reinstatement. He attached Smart Cutter grinding panels to a Twister tool with a panel hub. The rotary action of the tool centralized the hub and grinding action inside the pipe. The variety of available Smart Cutter grinding panels and hubs allowed him to return to the joint after opening the liner to dress the reinstatement’s edges. This ensured a smooth finish for improved flow characteristics and to resist buildup in the line.
For more difficult reinstatements, Steckmann used a high-precision, remote control Trydent 80 lateral cutter system by Try Tek Machine Works. The Trydent is a maneuverable, precision-controlled, water-powered router with 100-ft-reach capability. The cutting heads for 3-, 4- and 6-in. pipe feature a color CCTV camera with lens wiper. Steckmann navigated its cutting heads through bends and even 90-degree elbows to cut through and to smooth reinstatement edges, watching the cutting operation on the unit’s display.
By July 2016, 2,000 ft of water and waste water lines of all 42 residential units inside three smaller buildings had been renovated through a combination of epoxy lining, CIPP and re-piping, with 220 units remaining. In addition, CuraFlo had rehabilitated 2,200 ft of 8- and 12-in. sewer lines outside the building.
LeMaire said that the Maui condominium project had already proven CIPP to be “one more arrow in our quiver,” a reliable method expanding CuraFlo’s capabilities for its customers. Adding CIPP to its offerings now permits the contractor to bid on jobs it had previously passed up, including projects specifying complete pipe renovation of both supply lines and drainage systems.
