PVC vs CPVC Pipe: Key Differences

PVC (Polyvinyl Chloride) and CPVC (Chlorinated Polyvinyl Chloride) are thermoplastic pipes widely used in water systems, chemical processing, and industrial applications. CPVC is produced by chlorinating PVC resin, which increases its chlorine content from approximately 57% to 63-69%. This additional chlorination raises the maximum service temperature from 60°C (PVC) to 93°C (CPVC) and improves chemical resistance to many industrial fluids.

The choice between PVC and CPVC depends primarily on operating temperature and the chemical environment.

Comparison Table

Property	PVC	CPVC
Chlorine content	~57%	63-69%
Max service temperature	60°C (140°F)	93°C (200°F)
Min service temperature	0°C	0°C
Tensile strength	48-55 MPa	55-62 MPa
Flexural modulus	2,750 MPa	2,900 MPa
Density	1.40 g/cm3	1.56 g/cm3
Pressure rating (SCH 80, NPS 2, 23°C)	15.3 bar	15.3 bar
Pressure rating (SCH 80, NPS 2, 82°C)	Not rated	7.6 bar
UV resistance	Poor (degrades)	Poor (degrades)
Flame spread	Self-extinguishing	Self-extinguishing
Joining method	Solvent cement	CPVC-specific solvent cement
Color	White, gray, dark gray	Light gray, off-white
Relative cost	1.0x	1.5-2.0x

When to Use PVC

• Cold water distribution (potable and non-potable) below 60°C
• Wastewater and drainage (gravity flow, non-pressure)
• Chemical waste lines (ambient temperature)
• Irrigation systems
• Electrical conduit
• Swimming pool piping

When to Use CPVC

• Hot water distribution (up to 93°C)
• Industrial chemical processing (acids, bases, salts at elevated temperature)
• Fire sprinkler systems (per NFPA 13, listed CPVC)
• Hot water recirculation loops
• Chemical plant utility piping
• Applications where PVC would soften or lose pressure capacity

Chemical Resistance

Chemical	PVC	CPVC
Sulfuric acid (< 70%)	Good	Excellent
Hydrochloric acid (< 35%)	Good	Excellent
Sodium hydroxide (< 50%)	Good	Good
Acetic acid	Good	Good
Sodium hypochlorite	Good (< 12.5%)	Excellent (< 12.5%)
Acetone	Not recommended	Not recommended
Aromatic solvents	Not recommended	Not recommended
Hot water (> 60°C)	Not rated	Excellent

Both PVC and CPVC are unsuitable for aromatic hydrocarbons, ketones, and chlorinated solvents. For hydrocarbon service in oil and gas applications, GRE pipe or HDPE pipe (for water service only) are alternatives.

Standards

Standard	Scope	Material
ASTM D1785	PVC pipe, SCH 40/80/120	PVC
ASTM D2241	PVC pipe, SDR-PR	PVC
ASTM F441	CPVC pipe, SCH 40/80	CPVC
ASTM F442	CPVC pipe, SDR-PR	CPVC
ASTM D2846	CPVC hot/cold water distribution	CPVC
EN ISO 15493	Plastics for industrial applications	PVC/CPVC

Pro Tip

PVC and CPVC use different solvent cements. PVC cement will not create a proper bond on CPVC pipe, and CPVC cement should not be used on PVC. Using the wrong cement is a common installation error that causes joint failures. Always verify that the solvent cement matches the pipe material, and follow the manufacturer’s cure time requirements before pressure testing.

Pressure Deration with Temperature

PVC and CPVC lose pressure capacity as temperature increases. The deration factor is applied to the cold-water pressure rating.

Temperature	PVC Deration Factor	CPVC Deration Factor
23°C	1.00	1.00
38°C	0.62	1.00
49°C	0.40	0.80
60°C	0.22 (max)	0.63
71°C	Not rated	0.50
82°C	Not rated	0.40
93°C	Not rated	0.25 (max)

This deration is the primary driver for specifying CPVC over PVC in hot water and elevated-temperature chemical service.

Read the full guide to pipe types