EverTUFF® CPVC Systems provide highly sustainable, cost effective alternatives to metal piping in commercial multi-story applications for hot and cold water distribution. EverTUFF® CPVC CTS piping is produced in Standard Dimensional Ratio (SDR) of 11, where the ratio of wall thickness to outside diameter of the pipe is a constant of 11. This produces the same pressure rating of 100 psi @ 180°F for all sizes.