Installation | Codes, Standards & Approvals
When we think about the harmful effects of UV light, we typically think about using sunscreen, wearing a hat, and staying in the shade. For those of us in the fire protection industry, we also think about the impact of UV light on CPVC pipe and fittings – and, unfortunately, the topic is plagued by misconceptions.
To set the record straight: UV light (most commonly sunlight) does not diminish the pressure-bearing performance of BlazeMaster CPVC. Yet the myth persists even after more than 40 years of successful installations of BlazeMaster CPVC. Why? There may be some confusion because sunlight does impact other types of pipes such as polypropylene and PEX, which are especially prone to sun damage. UV light damages some materials because it creates free radicals that can cause chemical degradation.
But CPVC is different because it is chlorinated, which prevents its molecules from breaking in pieces when exposed to free radicals. In fact, exposure to UV light is a key part of the CPVC production process. The resin is chlorinated using UV light as a catalyst. This chlorination process is also what makes BlazeMaster pipe and fitting systems flame resistant.
BlazeMaster CPVC pipe is also opaque, as opposed to translucent materials such as PEX. Opacity prevents the UV light from penetrating deeply into the wall of the pipe, limiting its effect to very near the surface. The ingredient that makes it opaque also serves to reflect light and dissipate UV energy, providing additional protection from the influence of the sun.
While UV light does not impact the long-term strength of the pipe, it can cause discoloration. The discoloration is caused by sunlight’s effect on the orange pigment additive, not on the CPVC itself. Exposure to UV light may also make the pipe somewhat more difficult to cut. The pipe also contains impact modifier additives – small particles of rubber that add ductility and make the pipe easier to cut. Rubber is damaged by sunlight, which can also make the pipe slightly brittle after extended sun exposure. This does not diminish the pipe’s pressure-bearing performance, but some caution is required when cutting it. Installers may need to use a fine-tooth saw rather than ratchet cutters.
How to Prevent Discoloration
Because UV light can cause discoloration, BlazeMaster pipe and fittings are shipped in coverings that are designed to protect against UV light. If the material must be stored outside prior to installation, the solution is simple: keep it in its original packaging and avoid exposing the pipe to direct sunlight for long periods of time.
But sometimes mistakes happen. If BlazeMaster pipe and fittings are removed from packaging and left in direct sunlight, this may result in discoloration and cause the pipes to become embrittled. While discoloration will have no impact on the system's ability to withstand water pressure or service life, pipes that become embrittled are tougher to install and require extra caution and special cutting tools.
Rest assured: it will not diminish the pipe’s ability to withstand water pressure and it will not shorten the system’s service life.
While BlazeMaster fire sprinkler systems have a UL and FM listing to be installed exposed, they are not commonly installed in areas with direct exposure to sunlight. However, there are some situations where CPVC may be exposed to UV light, such as when it is installed near a window or skylight. Even under these conditions, BlazeMaster fire sprinkler systems will perform as planned and have a long service life.
This puts to rest one common myth about BlazeMaster fire sprinkler systems. Unfortunately, other misconceptions about BlazeMaster remain common. To set the record straight, download Six Common Misconceptions About CPVC Fire Protection Systems. You’ll get the facts about issues such as flame resistance, commercial applications, cost, and others.
