Author’s note: This is a case study that I wrote for Aquatherm about use of its large-diameter Polypropylene-Random pipe for an HVAC retrofit project. The customer, deciding that it doesn’t like favorable publicity, opted to kill the story, so I’ve stripped out any information that might identify the owner or its facility manager. Nevertheless, the project was a huge success for the contractor, engineer, wholesaler and manufacturers’ rep. The facility manager was happy, too, although his bosses won’t allow him to say so.
BY ROBERT P. MADER
The physical plant at an East Coast educational institution was in need of some TLC when its new facility manager took over in 2015. The building owner had made some improvements before that — Harsco 4.3 million Btuh gas condensing hot water boilers and Trane CenTraVac R123 low pressure chillers had been installed around 2012. The overall system, however, was not being utilized properly, the facility manager said. Equipment wasn’t coming on when it should have, or it was operating continuously, or it wasn’t modulating properly. He has the plant running efficiently now via a Carrier i-Vu BACnet enabled building automation system. Carrier promotes the control system’s flexibility, allowing it to work with most manufacturers’ equipment. Proper control is saving the site a lot of energy and a lot of money, he noted.
But one last big project remained — replacement of condenser water piping between the chillers and the cooling towers. The existing piping was black steel and it was severely corroded.
“The black pipe was scaled out,” he said of the 20-year-old steel pipe. “We were dropping chunks off of it.”
Replacing large diameter black steel pipe in sizes up to 24 inches is a major undertaking because of the weight of the pipe and how long it takes to weld joints. Eighteen-inch Schedule 40 black steel pipe, for example, weighs nearly 105 pounds per foot. Welding large diameter black steel pipe can take more than a day per connection, said mechanical contractor Joe Estock, Estock Piping Co. LLC, Chesterfield, N.J.
The material handling challenges, plus the length of time it takes to weld black steel, bumped up against the facility’s time constraints. Any time the temperature goes above 60°F, the chillers come on, the facility manager said. The site had a four-month window this past winter to get the piping changed out. The project included installation of two new Baltimore Air Coil four-cell cooling towers.
Those “chunks” falling off the black steel pipe were clogging the strainers and potentially damaging the pumps and chillers, said the consulting engineer on the project. When the client asked for a solution, the consulting engineer said colleagues agreed that Aquatherm blue pipe had been used successfully in the U.S. for the past 10 to 15 years. The engineers visited two Aquatherm installations and the owners told them that they were happy with the Aquatherm pipe.
To be evenhanded, the engineering firm designed the retrofit with both black steel and with Aquatherm blue pipe. The Aquatherm pipe turned out to be less expensive to install, plus the client preferred it, so it was an easy decision. The engineer said he wouldn’t hesitate to specify Aquatherm products in the future.
Corrosion of black steel or cast iron, especially when installed outdoors, is a significant problem that can result in reduced inside diameter of the pipes and premature pump failure, said manufacturers’ representative Lou Garavito, Wallace Eannace Associates Inc., Plainview, N.Y.
“The cost of using steel is not just the installation,” Garavito said. “It’s the hidden costs that have to be recognized by the facility manager and the owner about the cost of a carbon steel or cast-iron system.”
Even treated pipe will rust and scale overtime, Garavito pointed out, especially if the pipe is exposed to chemicals. That makes Aquatherm PolyPropylene-Random (PP-R) pipe an ideal solution for projects like this one.
Eliminates welding hazards
Use of Aquatherm PP-R pipe also solves several other problems for a mechanical contractor, Garavito pointed out. The contractor doesn’t have to store acetylene. No fire watch is required. It eliminates material handling problems of steel pipe. Personal protective equipment is critical because grinding steel pipe can cause eye injuries.
Since there’s no welding, there are no welding fumes, noted contractor Estock. This is an issue in occupied structures that are undergoing a retrofit. For example, Estock performs a lot of school work and school administrators don’t want students exposed to welding fumes. That forces the contractor to work at odd hours.
Estock, who’s been piping boiler rooms since 1988, won the project against 10 other bidders. The Aquatherm pipe cost more than black steel, he said, but the labor savings more than made up for it. When he won the job, he got worried; he had zero experience with Aquatherm and didn’t know what he had gotten himself into. He turned to Eric Reilly at Ferguson Enterprises for help.
Reilly helps contractors install Aquatherm pipe in Ferguson’s Northeast District, which includes eastern Pennsylvania, New York, New Jersey, Delaware and northern Maryland. Reilly views his role as making sure contractors are comfortable with the product and have everything that they need to do the job. Ferguson has a national rental center that moves millions of dollars’ worth of equipment, including McElroy Manufacturing Inc. pipe fusion tools, to wherever contractors need them.
“That’s what we do at Ferguson,” Reilly said. “That’s why we sell so much of this stuff, because we do the extra work to make sure that the guys are comfortable and have a good experience. It’s my job to make things as easy as possible.
Reilly trained Estock and his pipefitters on how to use the tools. Reilly estimated that he spent three to four days total onsite but noted that Estock’s fitters are highly skilled and quickly got the hang of the Aquatherm system.
Reilly said that Estock’s crew needed some scissor lifts and a couple forklifts to move the Aquatherm blue pipe around the jobsite, but that it was light enough that they could easily make fusion joints with the pipe in the air. Aquatherm 18-inch blue pipe weighs 22.9 pounds per foot and comes in 6-meter lengths, or about 19.5 feet.
Estock gives Reilly a lot of credit for making the job easy.
“Put yourself in my shoes,” Estock said. “I’m a contractor who had never used this product before, plus the job itself had difficulties like 18-inch pipe going over top of new boilers. That, coupled with this being my first time using it, made me very nervous at the beginning, honestly.”
He was more nervous when he was told he would be performing the largest Aquatherm job in his region. He didn’t have to worry for long, though, because his men caught on quickly.
Fabricated assemblies onsite
Estock’s crew did all the fabrication themselves for assemblies such as manifolds inside the college’s large mechanical room.
The top advantage of the Aquatherm blue pipe for Estock was the weight. His crew could carry 10-inch and 12-inch pipe sections without using material handling equipment. A standard 21-foot length of 18-inch steel pipe weighs 2,200 pounds. Installing 18-inch pipe over the boilers as Estock had to do would have been extremely difficult with black steel.
The second big advantage was the speed of making heat fused joints in PP-R pipe. Estock said he could fuse 18-inch Aquatherm pipe in an hour and that it would take more than a day to weld an 18-inch joint in black steel.
“With the time constraints, God knows what would have happened if this were black pipe,” the facility manager said. “We might still be welding down there.”
The third big advantage for the contractor was elimination of all the drawbacks of welding, such as welding fumes and need for a fire watch. Estock does a lot of work in public occupancies, and none of them want a contractor to weld when the public is in a building.
“It’s a phenomenal way to go,” the facility manager said. “The dollars are neck and neck, but with the durability and no scaling and the ‘green’ element it brings, it’s leaps and bounds ahead of black steel now. Of course, we’ll find out in five to 10 years from now how it goes, but if you maintain it, it should be years and years and years of success. I see no issues with it. We’re glad that the [building owner] invested in this. It’s a great installation for all the parties involved. Everybody’s a winner in this. Winner, winner chicken dinner. It ain’t getting better than that.”