Approved for light-hazard standalone and multipurpose sprinkler systems in both concealed and exposed settings, chlorinated polyvinyl chloride (CPVC) pipe and fittings meet the requirements of all major building codes as an alternative material in modern sprinkler-system design.
Found in high-rise buildings, hotels, healthcare facilities, and college dormitories in more than 40 countries, CPVC has proven to be a highly effective alternative to steel pipe in light-hazard, wet-sprinkler systems. First used in water-distribution systems in 1959 and introduced to the fire-sprinkler market in the 1980s, CPVC piping systems have steadily grown in popularity because of their unique combination of features and benefits.
In commercial facilities, specification and installation is in done in accordance with NFPA 13: Standard for the Installation of Sprinkler Systems. The pipe also meets requirements for several other National Fire Protection Association (NFPA) codes for single- and multi-family residential installations. In fact, NFPA regulations specify that CPVC pipe and fittings are the only nonmetallic system permitted for use in a standalone fire-sprinkler system or one that's installed in an exposed environment, thanks to the material's superior performance capabilities.
To understand why CPVC fire-sprinkler systems have gained an increasingly greater market share in the sprinkler industry, it's important to understand the features and benefits of this alternative piping material.
Durability and Long Service Life
With their natural immunity to scale, corrosion, and microbiologically influenced corrosion (MIC), CPVC pipe and fittings offer long, low-maintenance service lives that typically exceed traditional metallic systems. CPVC systems have a 50-year life expectancy and are rated for continuous service for 175 pounds per square inch (psi) at 150-degrees F. The life expectancy of steel varies depending on corrosion factors and other environmental considerations.
A calculation known as the Hazen-Williams C-factor is used to describe the amount of friction loss - the loss of pressure caused by the resistance of water flow. Pipe size and fluid velocity influence friction loss. CPVC pipe has a C-factor of 150; steel pipe's C-factor is 120 when it's new, and decreases as it ages, due to scale build-up. A higher C-factor value results from the pipe being smoother and providing better friction resistance and, thus, improved flow. CPVC's higher value often allows for downsizing of pipe diameter, which results in cost efficiencies.
Superior Flame and Smoke Characteristics
When it comes to flame and smoke, CPVC pipe and fittings compare favorably to other nonmetallic piping options: They aren't combustible and won't contribute to flashover.
CPVC piping systems have a flash-ignition temperature of 900-degrees F., depending on the manufacturer. This is the lowest temperature at which sufficient combustible gas is evolved to be ignited by a small external flame. Many other ordinary combustibles (such as wood) ignite at 500-degrees F. or less. Consequently, CPVC fire-sprinkler systems cannot be the ignition source of a fire.
Additionally, CPVC piping systems will not sustain burning. This material must be forced to burn because it has an exceptionally high Limiting Oxygen Index (LOI). LOI is the percentage of oxygen needed in an atmosphere to support combustion. The Earth's atmosphere is only 21-percent oxygen, and CPVC has an LOI of 60. This means that CPVC pipe and fittings will not burn unless a flame is constantly applied. They will stop burning immediately when the ignition source is removed. Any smoke generated from CPVC is considered no more toxic than standard building materials.
Because of their outstanding 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.
Easy to Handle and Install
CPVC piping systems are easier to install than metal systems. Pipe is lightweight; field fabrication is quick, simple, and clean; and there is no need for a soldering torch or heavy equipment.
Installation also is fast, thanks to the system's one-step, low-VOC solvent cement joining process.
And, during retrofits in existing buildings, CPVC piping systems offer these additional installation advantages:
- Less downtime.
- Faster completion.
- Less disruption to building occupants.
- Flexibility to install the system on walls or ceilings, or even in tight spaces (due to a lightweight, less-rigid design).
Greater Cost Efficiency
Unlike metal systems, CPVC pipe and fittings have not experienced skyrocketing prices over the past few years. CPVC systems have a more controlled, stable material cost than metal piping. And, because it's faster to install, CPVC systems can save up to 50 percent on labor costs in comparison to metallic systems.
It's important to note that not all CPVC fire-sprinkler pipe and fittings are the same. Because the compounds used to make CPVC pipe and fittings are derived from different base resins, performance is not necessarily consistent among products.
Some CPVC resins and compounds are developed specifically to optimize performance for individual applications. They also may be designed to meet or exceed existing code and approval requirements. Be sure to check with individual manufacturers to ascertain performance history, listings and approvals, and product compatibility.
In general, CPVC has demonstrated through both laboratory tests and actual installations that it offers long-term durability and performance, as well as greater cost efficiencies, when specified in fire-sprinkler systems instead of traditional metallic piping components. This provides end-users with a sprinkler system that is cost effective, safe, and reliable.
Matthew Kuwatch is the global marketing manager at Cleveland-based BlazeMaster® CPVC Fire Sprinkler Systems and the executive director and vice chairman of the Steering Board for the Ohio Fire Safety Coalition. He is a member of the National Fire Protection Association, the American Fire Sprinkler Association, the Intl. Fire Sprinkler Association, the Society of Fire Protection Engineers, and the Home Fire Sprinkler Coalition.