Application: CPVC Piping Conversion Helps Eliminate Corrosion

When your wastewater treatment plant is expected to be operational 24/7 and is under the additional pressure of treating a wide variety of harsh industrial chemicals in the water stream, you can't afford downtime as a result of corrosion and leaking pipes.

When your wastewater treatment plant is expected to be operational 24/7 and is under the additional pressure of treating a wide variety of harsh industrial chemicals in the water stream, you can't afford downtime as a result of corrosion and leaking pipes. That was the challenge faced by Lubrizol's Avon Lake (Ohio) wastewater treatment plant back in 2005.

Lubrizol, a global manufacturer of specialty chemicals, manufactures an array of chemical products at its Avon Lake plant, including thermoplastic polyurethane, polyurethane dispersion (PUD), high performance latex products and a variety of additives primarily used in personal care products.

To effectively treat a diverse mix of process waste streams before sending its water back to the local municipal plant, Lubrizol uses an alum-based polymer coagulant to break solids out of the solution and into suspension. The coagulant, which weighs 25% more than the weight of water, is pumped through a one-inch line and fed into the wastewater in a mix tank. The challenge, until 2005, had been the low pH level of the feed stream, which wreaked havoc on the pump room's stainless steel piping system.

According to Tim Dillon, Lubrizol's operations supervisor for wastewater treatment and facilities, the stainless steel line had been in operation for nearly two years when it started to develop ongoing corrosion problems. Facility staff decided to replace the line with CPVC pipe and fittings.

Dillon's team was already familiar with the benefits of CPVC because, nearly 10 years earlier, CPVC pipe and fittings were installed for the polymer coagulant bulk unloading line. More than a decade later, the CPVC system was still operating reliably without any downtime or maintenance issues.

After three years of 24/7 operation, the newer CPVC line installed in the pump room's polymer coagulant feed line is demonstrating the same reliable performance. "We have had zero problems with the CPVC system," said Dillon.

In addition to the system's corrosion resistance, Dillon noted that another reason for using CPVC piping was its higher heat deflection temperature which is noted by the cell class of the pipe material - 24448 -- as defined by ASTM D1784. This meant the pipe would appear rigid and not sag once in service.

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