How FlowGuard® CPVC Pipe Gets Its Pressure Rating

A pipe pressure rating tells a system designer how well a thermoplastic material will withstand the internal stresses placed by the fluid being conveyed over time at various temperatures. When working with FlowGuard® CPVC pipe, designers should know that the pressure bearing capability of the pipe has been proven in a rigorous data collection and analysis process that has been established by the Hydrostatic Stress Board of the Plastics Pipe Institute (PPI).  

In this process, more than 16,000 hours of data are produced on three separate lots of FlowGuard® pipe specimens. That data is then extrapolated to 100,000 hours.

Safety Cushion of 2 Incorporated into System Pressure Calculations

Of particular note is that the calculations to determine the pipe pressure rating incorporate a safety factor of 2 for pipes rated according to ASTM standards. This reflects the maximum allowable pressure stress a pipe should withstand under actual service conditions. The cushion ensures that even if the pipe is pressured to its design limit, fully half of its material strength is reserved over its lifetime for real-world stresses other than pressure bearing. These could include factors related to installation, lot-to-lot variability and exposure to chemicals.  

Also of note is that FlowGuard CPVC fittings are manufactured from pressure-rated CPVC compounds as well. With an independently verified and certified pressure rating for the fittings, you can be confident that the entire FlowGuard CPVC system – not just the pipe – can withstand long-term high-temperature hydrostatic pressure.

The pressure rating that eventually gets printed on each piece of FlowGuard CPVC pipe has the benefit of rigorous testing and industry oversight that rises well above mere performance claims. As you start to consider your next project, contact us with any questions.