CPVC pipe can last 50 years or more, and plumbers commonly quote 50 to 75 years, though no standards body publishes an official lifespan. It does not rust or corrode, so age alone rarely ends it. Heat, brittleness, poorly made glued joints and contact with incompatible chemicals cause most early failures.
CPVC is chlorinated PVC, made for hot and cold water supply lines, while plain PVC carries drains and sewer lines, as covered in how long PVC sewer pipe lasts. Lubrizol, which developed the FlowGuard CPVC compound, reports original CPVC still in use in a research home more than 60 years after it went in.
The weak spots are well known. Charlotte Pipe, a FlowGuard Gold maker, rates the pipe for water up to 180 degrees Fahrenheit and notes that plastics become more brittle over time. Brittle pipe can crack when it is flexed, struck or cut with the wrong tool. A forensic plastics engineer at The Madison Group also warns that some fire caulks, cable jackets and pest repellents contain plasticizers that cause stress cracking, sometimes within a few years. A badly made solvent-cement joint, or pipe with no room to expand as hot water runs, fails sooner too.
The honest limit is that age alone does not tell you when CPVC is finished. A 25-year-old line that runs hot and was stressed at installation can crack at its fittings before an older, cooler one does, and brittle pipe can break during an unrelated repair. Repeated leaks at fittings are a better guide than the build date. Repiping is the long-term fix, and PEX is a common replacement.