Fire & Life Safety

Fire Sprinkler Systems

Chlorinated polyvinyl chloride (CPVC) pipe is an increasingly popular option for sprinkler systems.
July 1, 2021
6 min read

Every 24 seconds, a fire department in the United States responds to a fire somewhere in the nation, according to data from the National Fire Protection Association (NFPA). Schools and colleges are not exempt.

Fires in K-12 schools cause an average of one death, 39 injuries and $37 million in property damage every year, the NFPA says. From 2011 to 2015, U.S. fire departments responded to an average of 4,100 structure fires per year in residence halls, fraternities, sororities, and other related properties. These fires caused annual averages of 35 civilian injuries and $14 million in direct property damage.

That’s why fire protection systems are important in schools and college campuses: to keep students, teachers and staff safe. Fire sprinklers are critical to protecting people and property because they suppress a fire and keep it from spreading; often the fire is out before fire crews arrive.

As Covid-19 wanes and schools plan to fully reopen, some districts are planning building modifications. That can make it a good time to retrofit the fire sprinkler system.

CVPC

In upgrading systems in school and university facilities such as classrooms, student housing, offices and other structures, the choice of piping materials is a critical first step to success. Steel pipe is the traditional choice, but chlorinated polyvinyl chloride (CPVC) pipe is an increasingly popular option.

CPVC is not limited to residential uses. In fact, CPVC is approved for use in a wide range of light hazard facilities where the quantity of combustible material is low, and contents would generate relatively low levels of heat if a fire occurred. That means CPVC is approved for use in schools, high rise buildings such as residence halls, offices, hospitals, churches and many other facilities.

In evaluating options, consider these characteristics CPVC pipe and fittings:

Performance: Contrary to misconceptions about CPVC, it will not melt in a fire. When installed per its listings, CPVC resists heat and fire and maintains its structure when directly exposed to flame. This ensures that a CPVC system will deliver water to effectively suppress a fire.

When CPVC is exposed to fire, a charring layer is formed on the outside of the pipe and fittings, which then functions as a thermal barrier that reduces the conduction of heat. Water flowing through the piping system also will cool the inside to further resist heat.

On the other hand, steel pipe is prone to corrosion, which can cause water flow levels to drop when it is needed to suppress a fire. Corrosion also creates a rough surface within the pipe that causes friction and may slow the flow of water in an emergency. CPVC is immune to corrosion and offers better hydraulics compared with steel so it yields maximum water flow.

Expense: CPVC is less expensive and easier to install than steel pipe. CPVC installation is a one-person job that is completed with basic hand tools and a quick, one-step solvent cement process. Because the material is lightweight and flexible, it is easy to move around a job site, and installers can fit it into tight spaces. There’s no pre-fabrication required.

By contrast, steel pipe is 84% heavier than CPVC, so it requires teams of two or more people using special equipment to move it around a job site. Steel installation also requires a power source, open-frame torches, offsite prefabrication and noisy threading machines. The pipe is rigid, making it a challenge to install in tight spaces or hard-to-reach areas.

CPVC also offers a significant advantage in material costs—especially as steel prices have risen over the past year. CPVC offers superior hydraulics, so designers can often use smaller diameter pipe and fittings.

All this translates to savings. For instance, installation of a fire sprinkler system enabled a school district in Texas to save 5% to 10% compared with steel.

Fewer disruptions

CPVC provides faster, less disruptive installation compared with steel. There’s no need for noisy equipment, and that creates fewer issues for building occupants. A CPVC installation may be useful in meeting tight deadlines, even when a building cannot be vacated for a retrofit.

For instance, the University of Texas Austin needed to retrofit its fire sprinkler system at a large residence hall with 3,000 beds and more than one million square feet of housing over an entire city block. The project team met a tight deadline—without requiring any students to relocate—by completing the project during daytime hours when students were unlikely to be in their rooms. Because the installation process is quiet and clean, CPVC installers completed the work without the noise and odors that are part of installing steel piping.

Wake Forest University faced a similar challenge. The school initially chose steel piping for retrofitting its residence halls. However, the lengthy installation process created problems. After switching to CPVC, contractors completed the work across nine residence halls during summer breaks.

CPVC has lower long-term maintenance costs than steel. Steel pipe is prone to issues that affect long-term performance. The combination of water, water treatment chemicals and oxygen causes corrosion that may result in pinhole leaks—potentially in less than two years. In addition, minerals in hard water attach to steel pipe walls, often near fittings and corners, which limits the flow of water.

By contrast, CPVC resists corrosion and scaling even in demanding environments such as in salt air or where water pH levels fluctuate. The use of CPVC also eliminates the need for costly nitrogen systems.

As a result, maintenance costs are lower, especially given a projected 50-year service life. If piping repairs are needed or a sprinkler head or drop needs changed out, CPVC piping can be easily cut out and replaced with minimal interruption or damage to the property.

Sustainability

Green building practices are important for schools and universities, and CPVC offers significant advantages over steel pipe. A review of the energy input and output associated with CPVC, including raw materials, production of resin, conversion to pipe, distribution and wholesale, installation and use, and removal and disposal, found that CPVC has half the environmental impact compared with steel with regard to carbon emissions and energy usage.

Schools that choose CPVC can save money, accelerate installation, minimize disruption, reduce long-term maintenance costs and ensure green building practices.

Lainey Liotta is Fire Protection Market Manager at Lubrizol Advanced Materials.

About the Author

Lainey Liotta

Lainey Liotta is Fire Protection Market Manager at Lubrizol Advanced Materials, which includes BlazeMaster® CPVC piping systems and freezemaster™ antifreeze for fire protection systems.

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