One question that comes up often as CPVC piping and fittings are considered for a fire sprinkler system installation is: “CPVC is plastic – won’t it melt in a fire?”
On the surface, it may seem to be a logical question. In truth, we have more than 30 years of successful applications worldwide that beg to differ. In fact, one of the most recent BlazeMaster® CPVC success stories saved at least one life and property at Manchester’s Barton Village.
BlazeMaster CPVC is designed to provide 50 years of service life and is used worldwide in private homes, tower blocks, schools, hospitals, office buildings and hotels. It is the most specified non-metallic fire protection system in the world.
Still, we are asked how a plastic material such as BlazeMaster CPVC can possibly stand up to temperatures that can exceed 500° C.
UL Test Proves Heat and Flames Are No Match for BlazeMaster CPVC
Underwriters Laboratories (UL) – known worldwide as the resource for product safety certification – lists BlazeMaster CPVC fire sprinkler systems to the requirements of UL 1821. Included in the listing requirements is a fire test that reaches peak temperatures at more than 500° C.
After approximately one minute, the sprinklers were activated and continued to activate after a total test time of 40 minutes. Watch a video of the test here.
As the test progressed, BlazeMaster CPVC did exactly what it was designed to do – continue to supply water to the sprinkler heads while forming a protective charring layer on the outside of the pipe to reduce heat conduction. That action allows the system to remain intact and keep water flowing through the pipe. The inner smoothness of the pipe is not compromised. The water flowing through the pipe also cools the outer diameter of the pipe, reducing the burn rate from the inside – and preventing the pipe from melting.
Keeping the system fully functional and operating is imperative. The UL 1821 test proves beyond a shadow of a doubt that BlazeMaster CPVC can take the heat. It survives – and doesn’t melt – at temperatures above its processing temperature too.
Seeing May Be Believing, But HOW Does BlazeMaster CPVC Retain its Integrity?
BlazeMaster CPVC (chlorinated polyvinyl chloride) is a unique formula that contains 67% total chlorine. By reacting the additional chlorine with the PVC (polyvinyl chloride) – which contains approximately 57% chlorine – BlazeMaster CPVC achieves a unique performance against direct flame over long periods of time to resist combustion or burning.
It offers the best classification that a non-metal material can achieve: Bs1d0. This classification translates in the following manner:
- Fire behaviour: B = low flammability, no contribution to flashover
- Smoke development: s1 = low smoke development
- Flaming droplets: d0 = no burning drops
BlazeMaster CPVC also carries a Limiting Oxygen Index (LOI) of 60. That means it requires an atmosphere containing 60% or more of oxygen to sustain a flame. Given that the earth’s atmosphere only containing 21% oxygen, the material features self-extinguishing characteristics. It stops burning the moment the flame is removed.
Would you like to know more about how BlazeMaster CPVC stands up to flames? Download our Guide to CPVC Fire Sprinklers today.
