Piping Systems > Specification > Fire Performance
Corzan® Industrial Systems are well suited for many process applications due to their outstanding resistance to many corrosive chemicals at temperatures up to 200°F (93.3°C).
When thermoplastic piping materials are selected, thought should be given to the fire performance characteristics of the material. Evaluating fire performance involves consideration of many factors, including:
- Ignition resistance
- Heat of combustion
- Limiting oxygen index
- Flame spread resistance
- Smoke generation resistance
Without the help of flame retardants and smoke inhibitors, Corzan CPVC inherently exhibits outstanding fire performance characteristics in terms of limited flame propagation and low smoke generation.
When coupled with its excellent balance of mechanical strength, low thermal conductivity, improved hydraulics and outstanding corrosion resistance, Corzan CPVC provides excellent safety and performance in a wide range of industrial process piping and ducting applications.
Corzan CPVC has a flash ignition temperature of 900°F (482°C), which 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°F (260°C) or less.
Flash Ignition Temperature Comparison
Corzan CPVC will not sustain burning under normal atmospheric conditions due to its very high Limiting Oxygen Index (LOI) of 60. LOI is the percentage of oxygen needed in the atmosphere to support combustion.
Since Earth’s atmosphere is only 21% oxygen, Corzan CPVC will not burn unless a flame is constantly applied and will stop burning when the ignition source is removed. Alternative materials will support combustion due to their low LOI.
Limiting Oxygen Index Comparison
Flame Spread and Smoke Generation
The flame spread and smoke generation characteristics of Corzan CPVC materials have been evaluated by a number of recognized test methods.
Flammability of Corzan CPVC has been tested in accordance with UL 94, which is used for determining the flammability of plastic materials used in the components and parts of finished products.
This test measures a material’s resistance to burning, dripping, glow emission and burn through. CPVC has achieved the highest rating available within the scope of this test of V0, 5VB and 5VA.
The ICC Evaluation Service tested water filled ½-in. to 6-in. Schedule 80 Corzan pipe in general accordance with UL 723 / ASTM E84. (Contact Lubrizol for a copy of the certification reports).
Factory Mutual Clean Room Materials Flammability Testing Protocol (FM 4910)
Due to the growing concern in the semiconductor industry over safety and the high cost associated with fires and subsequent cleanup, Factory Mutual developed a standard (FM 4910) for semiconductor clean room materials.
FM 4910 requires that materials provide greater resistance to flame and smoke development, therefore limiting the damage that can be caused by fires.
Corzan CPVC compounds have been evaluated and pass the FM 4910 test protocol for fire propagation & smoke development. These compounds include gray duct compound (for manufacture into seamless, round extruded duct), gray pipe compound, and the Corzan 4910 compounds, which are used to manufacture sheet for fabrication into cleanroom equipment.
In some cases, manufacturers of finished Corzan CPVC pipe and fittings will perform the testing required to obtain a product listing independent of Lubrizol. Consult the manufacturer to obtain these listings.