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Quick answer: Charlotte Pipe publishes a do’s and don’ts list for FlowGuard Gold and Corzan CPVC water systems. The big ones:
- Never test with air or any compressed gas, and never use CPVC to carry compressed air. Charlotte warns this may cause injury or death.
- Check compatibility of thread sealants, lubricants, firestop, sleeves, insulation, caulks and other products; no petroleum- or solvent-based paints or sealants, and no edible oils like Crisco as lube.
- Don’t spray-foam it. Charlotte does not recommend polyurethane spray foam insulation with its CPVC.
- Let it move: straps that fully encircle the tube without restraining it, holes 1/4″ larger than the pipe through wood studs, isolators through steel studs.
- Brass compression ferrules are OK only up to 140°F, with PTFE tape over the ferrule, and don’t over-torque.
Rules come from Charlotte Pipe’s Plastics Technical and Installation Manual (pages 78–79), read October 9, 2026. We read them from the rendered manual pages. Charlotte calls its list not complete; follow codes and the manual. This page has no buy buttons.
Charlotte’s Do’s
- Keep pipe and fittings in their packaging until needed; cover them with an opaque tarp if stored outdoors.
- Use only latex paint if you paint CPVC.
- Use tools made for plastic pipe; cut square; deburr and bevel before cementing.
- Apply primer and cement with an applicator about half the pipe diameter, and rotate the pipe 1/4 to 1/2 turn as you insert it. Avoid puddling cement.
- For CPVC Schedule 80, Charlotte names IPS P-70 or Oatey Industrial Grade primer and IPS 714 or Oatey CPVC Heavy Duty Orange cement.
- Follow the cure time for the pipe size and temperature before testing.
- Fill lines slowly and bleed all trapped air before a hydrostatic test; visually inspect every joint.
- Use straps that fully encircle the tube; drill holes 1/4″ larger than the pipe’s OD through wood studs; use isolators that allow movement through steel studs.
- Use metallic or teardrop hangers when hanging tube from all-thread rod.
- If you sleeve through a slab, use a CPVC-compatible sleeve extended 12″ above and below the slab.
- Backfill and cover underground piping before termiticide is sprayed for a slab.
- De-rate all components if working temperature will exceed 73°F.
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Charlotte’s Don’ts
- Don’t test with, or convey, compressed air or gas.
- Don’t use cement past its shelf life or that has discolored or gelled; don’t use it near heat, flame or smoking.
- Don’t hydrostatically test before the recommended cure time.
- Don’t restrict expansion or contraction; don’t use straps or wedges that restrain the system; don’t install in cold weather without allowing for thermal expansion.
- Don’t bend CPVC so it puts stress on a fitting; don’t install fittings under stress; don’t end a run against an immovable object like a wall or joist.
- Don’t use an external heat source to bend CPVC.
- Don’t let heavy termiticide concentrations contact the pipe, or inject termiticide between pipe and sleeve.
- Don’t exceed 8 ft/s flow velocity for CPVC CTS, or 5 ft/s for CPVC Schedule 80.
- Don’t connect CPVC CTS or Schedule 80 CPVC directly to a boiler.
- Don’t use dull or broken cutter blades; in low temperatures Charlotte recommends a wheel-type cutter made for plastic pipe.
Connecting CPVC to Fixtures
Charlotte says CPVC CTS can be used for stub-outs for lavatories, toilets and sinks. Because CTS CPVC has the same OD as copper, it works with standard brass compression ferrules where the operating temperature won’t exceed 140°F; wrap PTFE tape over the ferrule to allow for the different expansion of metal and plastic, and don’t over-torque, which can crack the pipe. Charlotte doesn’t recommend nylon or other non-metallic ferrules.
Related Guides
FAQ
Can I air test CPVC?
No. Charlotte says never test CPVC with air or any compressed gas, because it may result in injury or death.
Can spray foam insulation touch CPVC?
Charlotte does not recommend polyurethane spray foam insulation with its CPVC, citing chemical compatibility and heat from the foam’s curing reaction.
Can I use compression fittings on CPVC?
With standard brass ferrules up to 140°F, per Charlotte, with PTFE tape over the ferrule and no over-torquing.
How big a hole for CPVC through a stud?
Charlotte says 1/4″ larger than the pipe’s outside diameter through wood studs.
Can CPVC connect directly to a boiler?
No. Charlotte says not to connect CPVC CTS or Schedule 80 CPVC directly to a boiler.
Sources
- TM-PL (PDF) (charlottepipe.com), read 2026-10-09