What Adapter For

How to connect PEX to CPVC pipe

Use a push-to-connect coupling in the pipes’ size, such as 1/2", or join them by thread with a CPVC x brass transition fitting and a brass PEX adapter.

What fits

A push-to-connect coupling

On the package: Push-to-connect coupling in your pipe’s size

both are copper tube size

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Push-to-connect coupling, copper, PEX and CPVC

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  • Shut the water off and drain the line before you cut anything.
  • Standard push-to-connect fittings take PEX and copper-tube-size CPVC together, with the PEX stiffener built in. Mark the insertion depth on each pipe and push to the mark.
  • Threaded instead: a CPVC x brass threaded transition fitting on the CPVC, and a brass PEX x pipe thread adapter on the PEX.

One is glued and the other is joined with rings or crimps, so use a fitting made for both.

More: Connecting different pipe

Common questions

Does the PEX stiffener get in the way of the CPVC?

No. SharkBite's Universal fittings from 3/8" to 1" have a PEX stiffener built in, and CPVC slides over it and holds it against the tube stop.

How hot can the water be at this joint?

SharkBite rates its fittings on PEX and CPVC to the pipe's own limits. Charlotte Pipe rates its FlowGuard Gold CTS CPVC for water up to 180°F at 100 psi, and SharkBite rates its own PEX pipe at 100 psi at 180°F.

Keep going

Connecting different pipeCPVC to copperPEX to copperSharkBite fittingsWhat pipe do I have?Garden hose to 1/2" pipeGarden hose to 3/4" pipe

For a different part on either end, open the adapter finder with this pair picked.

Where we get our information from

The sizes on this page come from published standards and the makers’ own documents. Checked against published data from SharkBite, Charlotte Pipe and Uponor.

See all 6 sources
  • SharkBite (Reliance Worldwide), SharkBite Installation Guide (2020): pipe insertion depth table, integral PEX stiffener
  • SharkBite (Reliance Worldwide), Push-to-Connect Installation Guide (pocket guide): stiffeners, transition fittings, warnings
  • SharkBite (Reliance Worldwide), SharkBite PEX Installation Guide (2021): fits copper, CTS CPVC and PEX in any combination
  • Uponor, PEX Piping Systems Installation Guide, seventh edition (2025): ProPEX expansion fittings, pipe colors, copper and threaded adapters, no soldering within 18" of PEX
  • Charlotte Pipe, Plastics Technical Manual (2026): PVC and CPVC colors, standards, temperature limits, Not for Pressure print, plastic-to-metal threads and brass transition fittings
  • Charlotte Pipe, FlowGuard Gold CTS CPVC submittal and product page: ASTM D2846, 180 F, solvent cement

General guidance from manufacturer and standards data. Parts vary by brand, so check the size printed on the package against what you measured. For gas lines or anything inside a wall, use a licensed plumber.