The CPVC Pipe are manufactured in Copper Tube size [CTS] from Â½ âto 2â. They have two different standard dimensional ratios SDR-11 & SDR-13.5. These pipes are made from CPVC compound. Apart from this CPVC Pipe & fittings are produced as per SDR-11 that meets the requirement of ASTM D 2846. The pipes with SDR-13.5 meet the requirement that is derived from ASTM F 442. The specific CPVC in Iron Pipe Size (IPS) dimension is dually fulfilled. Further they have same physical properties. SDR-11 and SDR-13.5 have different wall thickness and therefore, at any given temperature & pressure rating.