Polypropylene-Random Pipe Eliminates Electrolysis in Tennessee VA Hospital

Aug. 1, 2011
Costs roughly $25,000 less than copper would have

At James H. Quillen VA Medical Center in Mountain Home, Tenn., the maintenance staff discovered the main 6-in. galvanized-steel water line, which ties into copper where reduced to a 4-in. line, was deteriorating.

"This union of two dissimilar metals was creating electrolysis in the galvanized pipe," Aaron M. Prosak, the facility's engineering technician, said.

The pipe was extremely brittle, requiring "near-surgical care," Prosak recalled, while Kevin Hoover of Ferguson Enterprises remembered the grooved steel "leaking, pitting, and deteriorating," with rupture imminent.

Weighing the Options
The system needed to be re-piped quickly, with limited disruptions to patient care and the hospital staff.

"Originally, the idea was to replace the galvanized to eliminate the electrolysis, and we planned to replace it with copper," Prosak recalled.

Then, local mechanical contractor ASI/Southern Mechanical Inc. introduced to the hospital staff polypropylene-random (PP-R) pipe manufactured by Aquatherm Inc. PP-R pipe, which is electrolysis-resistant, corrosion-proof, chemically inert, and durable, has been used in more than 70 countries for nearly four decades. The heat-fusion process used to connect pipes and fittings is virtually leak-proof, and the pipe carries an extensive warranty when installed by Aquatherm-trained and certified technicians.

After in-depth research, Prosak and his staff requested a heat-fusion demonstration conducted on site by Aquatherm and the Knoxville office of Ferguson Enterprises.

"During this demonstration, we were able to see cutaway sections of fusion welds," Prosak recalled. "The two sections of pipe blended nicely into each other. We also found that Aquatherm offered the 10-year, $9 million warranty."

Still, Prosak had reservations.

"The idea of installing Aquatherm pipe was a change for us," Prosak said. "Our maintenance staff has experienced plumbers that have been in the industry for 20 to 30 years. Copper is the industry standard and is trusted and works if it is sweat or brazed properly."

Yet, with approval from the regional Veterans Affairs headquarters, the center proceeded with the project, which began in November 2010. Prosak said some of the uncertainty was resolved with the installation of six additional branch lines with 1-in. ball port valves with threaded connections along the main for isolation purposes and any future renovations.

With more than 400 valves and fittings, Aquatherm generally can transition with at least as much flexibility as other pipe systems. The hospital negotiated with the contractor for the equipment necessary to work on 4-in. and smaller polypropylene pipe.

Fusion Leads to Labor Savings
David Tyree, superintendent plumber with Southern Mechanical, used several offset 45-degree fittings to maneuver around existing steam lines, galvanized pipe, chilled-water supply and return lines, information-technology cables and computer wiring, and sprinklers.

Six-inch, standard-dimension-ratio 7.4 Aquatherm Greenpipe, which is designed for potable-water applications, was used for the main. Roughly 300 ft of Greenpipe picks up downstream of the flow preventer, goes into the ceiling, branches off twice to feed pumps, out into the bottom-floor main hallway, and then feeds all of the different outlets.

Aquatherm's fusion outlets—special fittings that fuse through pipe walls, allowing branches—were used instead of Ts, saving a lot of labor time, Tyree said. Additionally, because the pipe was routed along a finished hall, some sections needed to be joined in place above existing utilities. A 32-ft trunk line traversing a vertical run in a chase also presented space challenges. Both sections were fused via electrofusion couplings.

This technique fuses pre-assembled pipes and fittings using an outer sleeve, which the two pipe ends slide into. An internal stop at the center of the fitting prevents the pipe ends from meeting. Fusion indicators inside the fitting indicate when sufficient melt pressure has been achieved. Electrofusion is ideal for repairs and situations in which work space and pipe movement are limited.

"Between using the fusion outlets, 6-in. tees and reducers, and 6-in. electrofusion couplings, we really saved a lot of labor time on this job," Tyree said. "If we were using copper, it never would have went in, or we would have likely burned the building down sweating it in there."

Eliminating the need for hot work in the chase and above the ceiling created a much safer work environment, Prosak said.

Despite involving the first Aquatherm electrofusion connections in the United States, the installation went smoothly, so well that during the latter portions of the project, Southern Mechanical and the facility staff conducted two days of heat-fusion training for all interested maintenance personnel.

The PP-R pipe's natural insulation value proved to be a benefit, Hoover said.

"Since the pipe has a natural R value of 1, we didn’t have to insulate it, like we would have had to do with copper, and that provided additional labor and material savings," Hoover said.

The project was completed in January 2011 without a single leak from the PP-R pipe, and all of the parties involved are pleased with the results.

According to Tyree, the job cost roughly $25,000 less with the Aquatherm pipe than it would have if copper had been used.

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About the Author


Lindon, Utah-based Aquatherm is the North American distributor of German-made polypropylene pipe systems.