CPVC

Summary

CPVC is polyvinyl chloride further chlorinated to roughly 63 to 69 percent chlorine by mass, which raises its heat resistance. It carries hot water to 200°F where PVC is limited to 140°F, so it is the usual plastic pipe for hot-water and sprinkler systems.

Cols

Image

CPVC: chlorinated polyvinyl chloride
Schedule 40 / 80: pipe wall classes
Solvent cement: chemical bonding agent for joints

History and demand

Invention

Early 1960s: CPVC tubing and fittings first made; B.F. Goodrich developed the original CPVC resin and Genova Products made the first tubing and fittings

Sourcing

Named leading producers include Lubrizol, Kaneka Chemical, and Sekisui Chemical; the top three hold over 60 percent of the market (market research)

Composition and production

Raw materials

Chlorine 56.7 to 74 percent by mass across manufacturers; most commercial resins 63 to 69 percent; unstable at about 70 percent

Properties

Physical

Density: 1.56 g/cm3 (97 lb/ft3)

Mechanical

Tensile strength: 50 to 80 MPa (7.3 to 11.6 ksi); Schedule 40 and 80 pipe 8,200 psi, versus 7,500 psi for PVC
Young's modulus: 2.9 to 3.4 GPa (420 to 490 ksi)

Thermal and moisture

Service temperature: 33 to 200°F (1 to 93°C); PVC 33 to 140°F (1 to 60°C)
Thermal expansion: 8 x 10-5 /K, about 4.4 x 10-5 in./in./°F
Thermal conductivity: 0.16 W/(m·K)
Glass transition and Vicat softening: 106 to 115°C (223 to 239°F)

Fire behavior

Self-extinguishing when not in direct flame

Standards

Material specifications

ASTM F493: CPVC solvent cements, primers, and bonding agents

Uses in buildings

Building elements

Domestic Water Piping: hot and cold water pipe
Fire Protection: sprinkler piping

Pros and cons

Pros

Rated 40 to 50°C (72 to 90°F) higher than PVC
Higher tensile strength than PVC in pipe sizes

Cons

Becomes unstable above about 70 percent chlorine
Solvent-cemented joints require compatible cement

Manufacturing and cost

Main manufacturers and suppliers

Trade association: Plastics Pipe Institute.

Sources

Wikipedia: Chlorinated polyvinyl chloride, https://en.wikipedia.org/wiki/Chlorinated_polyvinyl_chloride
Wikimedia Commons: CPVC tees.jpg, photo by Asadabbas (CC BY-SA 4.0), https://commons.wikimedia.org/wiki/File:CPVC_tees.jpg
MarketResearch.com: global chlorinated polyvinylchloride (CPVC) market, https://www.marketresearch.com/APO-Research-Inc-v4273/Global-Chlorinated-Polyvinyl-Chloride-CPVC-40474333