PM Engineer

Guest Editorial: Pipe Analysis

by Matthew Kuwatch

August 1, 2011

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CPVC provides commercial sector with sustainable choice for fire sprinkler systems. 

As the commercial building industry continues to focus on sustainability and ways to promote itself as green, a number of rating and certification programs have emerged as a means of objectively evaluating the environmental impact of products and projects. 

With so many different rating systems and certification programs available, it is often difficult for decision makers and purchasers to choose the most environmentally friendly alternatives.

The Life Cycle Assessment has emerged as a credible, data-driven approach to assessing a product’s true environmental value. An LCA is a comprehensive examination of a product’s environmental and economic impact and potential throughout its lifetime — cradle to grave — including raw material extraction, transportation, manufacturing, use and disposal. There are, of course, many other tools for evaluating environmental impact, but if you only consider one impact at a time, it is easy to unintentionally shift environmental burdens by improving one category at the expense of another. This is not the case with an LCA, because it looks at the entire product life cycle from many different perspectives and allows you to see those tradeoffs. 

In recent years, several different LCAs have been conducted to compare the environmental benefits of materials commonly used in piping systems. Although several piping materials were studied, at the heart of the analyses was a comparison of steel vs. chlorinated polyvinyl chloride, since CPVC has grown significantly in popularity in recent years as a result of its performance and cost advantages. In fact, CPVC is the most often specified nonmetallic fire sprinkler piping material in the world today because it offers an unmatched combination of benefits,  including corrosion resistance, a fast and easy installation process, a lightweight, versatile design and lower total installed costs.

Last year, one particular ISO-compliant peer-reviewed LCA was conducted on a brand of BlazeMaster CPVC fire sprinkler pipe and fittings, which was then used in an LCA comparison with Schedule 10 IPS steel pipe. The functional unit of the study was 1,000 ft. (304.8 meters) of piping installed and used in a high-rise, multifamily building in the United States for a 50-year period.

It’s important to note that since the LCA examines a specific production facility and manufacturing process, the results of this study are brand-specific and cannot necessarily be interpreted to cover all brands of CPVC fire sprinkler piping.

The Envelope, Please

was assumed 100% of steel pipe is recycled and 0% of the CPVC pipe is recycled. In a more real-life scenario, the CPVC score would have been even higher over steel to take into account not all steel pipe is recycled.

Significant resource depletion (fossil fuels used in steel manufacturing) is a key reason why steel receives overall lower scores despite its ability to be recycled. Steel has the highest resource depletion impact due to the use of coke in steel production and the significantly higher weight of material required in steel piping when compared to CPVC.

Based on the results of the “cradle-to-grave” study, which was conducted by Environmental Resources Management, an environmental consulting group, the BlazeMaster CPVC pipe and fittings proved to be the more sustainable choice.

In this particular LCA, 13 environmental impacts were studied, including: metal depletion, fossil depletion, terrestrial acidification, freshwater eutrophication, climate change, ozone depletion, human toxicity, freshwater ecotoxicity, photochemical oxidation, terrestrial ecotoxicity, water depletion and energy consumption (both nonrenewable and renewable energy use).  The CPVC pipe and fittings received superior marks over steel pipe and fittings in 12 of the 13 categories. The only exception was in the category of ozone depletion as a result of the use of chlorofluorocarbons in the production of PVC. In many categories, such as human toxicity and freshwater ecotoxicity, the performance difference between CPVC and steel was dramatic.

The impacts related to distribution, installation, use, removal, transport and packaging were determined to not be significant for any of the systems. The increased installation and removal time required for the steel pipe does increase the importance of this category slightly, but not enough to consider the life-cycle stage to be a main contributor. As can be expected, the impact from transport increases with steel due to the heavier weight. Of interest is even though steel is currently the only material that is recycled at the end of its service life, the other systems have the potential to be recycled. In fact, there are already systems in place to begin testing ongoing recycling operations for CPVC.

More Building Benefits

Although much of the focus today is on green products, specifiers are still interested in products that deliver all-around value and safe performance. Here are a few more reasons why CPVC is today the material of choice for many hotels/motels, hospitals, universities and high-rise buildings in more than 60 countries across the globe.

Superior hydraulics: The Hazen-Williams C factor is used to describe the amount of friction loss encountered when water flows through a pipe. Steel pipe has a C factor of 120 compared to the 150 C factor of CPVC pipe. This higher C value indicates CPVC pipe has less friction loss, which often allows for pipe downsizing of at least one size smaller in diameter than steel.

Flame and smoke resistance: Compared with other nonmetallic piping, CPVC is not combustible and will not contribute to flashover. CPVC piping systems have a flash ignition temperature of 900° F, depending on the manufacturer. This is the lowest temperature at which sufficient combustible gas is evolved that can be ignited by a small external flame. Many other ordinary combustibles, such as wood, ignite at 500° F or less. As a result, CPVC fire sprinkler systems cannot be the ignition source of a fire. CPVC piping systems also will not sustain burning because they require more oxygen than what is in the atmosphere.

Because it offers outstanding resistance to fire and low smoke generation qualities, CPVC fire sprinkler piping systems are even approved for use in plenum spaces in accordance with NFPA 90A: Standard for the Installation of Air Conditioning and Ventilating Systems.

Today there are more piping material options than ever before. CPVC represents a highly viable option for today’s commercial building market, delivering benefits to the installer and end user as well as to the environment.

Matthew Kuwatch
Matthew Kuwatch is the global business director for BlazeMaster CPVC fire sprinkler systems of the Lubrizol Corp. Kuwatch is a member of numerous fire protection associations, including NFPA and the Society of Fire Protection Engineers. He also is the executive director and chairman of the board for the Ohio Fire Safety Coalition.

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