Electrofusion Fittings Solution Facilitates the Upgrade of a Wastewater Treatment Plant

History

The small commuter city of North Bend, Washington is home to over 7,000 people and is known for being a film location for television series Twin Peaks. In 2019, construction began on the city’s wastewater treatment plant (WWTP) in order to upgrade its capacity and replace decades-old equipment. The upgrade includes a new building for the ultraviolet (UV) disinfection system, effluent sampling station, and upgraded electrical panels.

The upgrade is part of a comprehensive wastewater system facilities plan that anticipates the needs of the city over a 20-year span. The upgraded WWTP aims to improve operations, create necessary system redundancy, increase employee safety, and meet environmental requirements.

Problem

As part of the North Bend WWTP upgrade, a new pipeline would need to be installed leading to the new UV treatment building. A 24″ IPS line was specified and a ditch was carved near the plant to facilitate installation. However, due to existing structures, the ditch was made narrower than usual. Additionally, the installers had to deal with a constant buildup of excess groundwater.

The challenging installation conditions meant there was a risk of delays for the pipeline, which could cascade over to affect the overall upgrade.

Solution

The installer chose AGRU America as its pipe fittings provider, citing AGRU’s inventory and availability as key metrics that would help improve installation time of the pipeline. The 24″ IPS electrofusion fittings are part of the AGRULINE system, which includes a wide variety of specialized fittings.

The electrofusion couplers used to connect the new pipeline at the North Bend WWTP are made with PE 100-RC, a pipe-grade resin that offers superior resistance to stress crack propagation when compared with PE 100 or PE 4710 standards. The fully automated manufacturing process allows AGRU to deliver precision engineered electrofusion fittings, including fully embedded heating wires. A fully embedded heating wire facilitates pre-welding preparation and helps reduce the chances of damaging the heating element during installation.

“By using AGRULINE in place of conventional fusion processes,” said Eric Antonelli, fusion technician at HD Fowler, “I estimate we saved between 50% and 70% on overall costs as a result of time savings and reduced reconstruction costs.”

Every aspect of the AGRULINE electrofusion welding process is made to simplify and improve the installation experience. The premium PE 100-RC used in the manufacturing of the fittings is compatible with most common polyethylene piping resins such as PE 4710. And because the fitting is made with such a durable material, the North Bend pipe joints did not require sand beds, which provided further installation time and costs savings.

The fitting also featured a bifilar welding system that simplified infrastructure requirements during welding, supported two separate welding zones, and incorporated tension belts for the perfect interfacial welding pressure.

“The ratchet straps were particularly impressive,” said Mr. Antonelli. “I think they worked very well in managing the welding pressure.”

Outcome

The new pipeline was successfully installed in record time and has been pressure tested for construction quality control. All results came back positive, with no problems of any kind reported.

“I found the instructions to be very concise and accurate,” said Mr. Antonelli, “and appreciate that Rick was available around the clock to provide advice about the operation of the processor and the fitting.”

“We take pride in our work and take our company tagline, the Plastics Experts, to heart,” said Rick Over, responsible for AGRULINE Technical Support-IPS Fittings at AGRU America. “Beyond delivering a high-quality product, we understand that modern problems require integrated solutions that combines industry-leading products and equipment with robust support.”

AGRU America’s electrofusion fittings solution was designed specifically to address the fluid, water, and gas transmission problem within U.S. water and wastewater infrastructure. A significant step in alleviating issues surrounding water transmission is to reduce leaks at pipe joints. Electrofusion welding through the use of electrofusion fittings yields a leak-free system free of internal obstructions and requires a minimum open trench during installation, reducing reconstructive costs.

“Ultimately, electrofusion promotes the creation of a leak-free homogenous piping system,” said Melissa Grace, AGRU America’s vice president of textile and AGRULINE. “With our solution, installers can minimize the risk of potential mechanical failure while also delivering to their end users the confidence that they are properly addressing the water transmission problem.”