FlowGuard™ Flex

UV Resistance

FlowGuard™ Flex 3 layer piping solution eliminates the variables associated with UV (ultraviolet) resistance - the second factor that can affect PEX piping materials. Unfortunately, there is no way to visually inspect PEX pipe to determine if it has been affected by UV exposure. There are also no ASTM standards proposed to address the issue. An ASTM task group has been formed based on this being a recognized issue.

Ultraviolet is a concern for solid wall PEX brands. This chart demonstrates how UV degradation can affect PEX products.

• The yellow line represents FlowGuard Flex 3 layer piping which always passes the NSF P171 Cl-recirculation test.
• The blue line represents a common single layer PEX-b silane PEX product.
• The red line represents a common PEX-a perioxide PEX product.

Chlorine resistance testing is used to calculate the negative effects of UV exposure to a PEX product's chlorine resistance. We find that the single layer silane product and the PEX-a peroxide product have noticeable decrease of chlorine resistance compared to the patented FlowGuard Flex 3 layer piping solution.

After only 84 hours of accelerated UV exposure (equating to three weeks of outdoor exposure [21 days x 4 hours per day]), the peroxide (Type A) PEX product (red line) loses its chlorine protection significantly faster than a common silane (Type B) PEX (blue line). It’s important to note that even with failure at 84 hours, the pipe visually looks unchanged.

After 1,000 hours of accelerated UV exposure (equating to approximately six months of outdoor exposure), the FlowGuard Flex technology (yellow line) shows little, if any, effect from UV.