CPVC Pipe Sizing Calculator & Complete Guide
Calculate CPVC pipe sizing for hot and cold water systems. Complete guide to CPVC properties, temperature ratings, flow capacity, and installation with free calculator.
CPVC (chlorinated polyvinyl chloride) pipe is specifically designed for hot and cold water supply applications, offering the benefits of plastic pipe with the temperature resistance needed for hot water systems. CPVC can handle temperatures up to 180°F, making it an excellent alternative to copper for hot water distribution. This guide covers CPVC sizing, flow characteristics, installation methods, and best practices for residential and commercial hot water systems.
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Friction Characteristics
CPVC pipe has a Hazen-Williams C-value of 150, identical to PVC and PEX. The smooth interior surface provides excellent flow characteristics, allowing for efficient water distribution in both hot and cold water applications.
Temperature Resistance
CPVC is rated for continuous operation at 180°F and can handle temperatures up to 200°F for short periods. This makes it suitable for all hot water applications, including recirculation systems and high-temperature supply lines.
Pressure Ratings
Schedule 40 CPVC has pressure ratings of 400 PSI at 73°F, decreasing to 100 PSI at 180°F. These ratings are suitable for all residential and most commercial hot water applications. CPVC maintains better pressure ratings at high temperatures than standard PVC.
Chemical Resistance
CPVC offers excellent chemical resistance, similar to PVC. It's resistant to most acids, alkalis, and salts, making it suitable for various water conditions. CPVC is also resistant to chlorine, which is important for municipal water supplies.
Hazen-Williams C-Value
Excellent flow characteristics - smoother than copper (C=140)
CPVC Pipe Flow Capacity (Schedule 40, C=150)
Maximum recommended flow rates (GPM) for Schedule 40 CPVC pipe at 6 ft/s velocity. CPVC maintains the same flow characteristics as PVC and PEX due to identical C-value.
| Nominal Size | Inside Diameter (in) | Max Flow @ 6 ft/s (GPM) | Pressure @ 73°F (PSI) | Pressure @ 180°F (PSI) |
|---|---|---|---|---|
| 1/2" | 0.485 | 3.3 | 400 | 100 |
| 3/4" | 0.700 | 6.9 | 400 | 100 |
| 1" | 0.945 | 12.6 | 400 | 100 |
| 1-1/4" | 1.245 | 21.9 | 400 | 100 |
| 1-1/2" | 1.480 | 31.0 | 400 | 100 |
| 2" | 1.935 | 54.1 | 400 | 100 |
Common Applications
CPVC Pipe is commonly used in the following applications:
- Hot water supply lines
- Cold water supply lines
- Hot water recirculation systems
- Radiant heating (lower temperature)
- Residential plumbing systems
- Commercial hot water distribution
- Well water systems (hot and cold)
Advantages
- ✓Suitable for hot water (up to 180°F)
- ✓Lower cost than copper
- ✓Smooth interior (C=150) for efficient flow
- ✓Easy installation (solvent welding)
- ✓No corrosion concerns
- ✓Lightweight and easy to handle
- ✓Good chemical resistance
- ✓Long lifespan (50+ years expected)
Disadvantages
- ✗More expensive than standard PVC
- ✗Requires special CPVC fittings and cement
- ✗Not suitable for outdoor exposure (UV degradation)
- ✗Becomes brittle in freezing temperatures
- ✗Requires proper support (sags more than metal)
- ✗Some codes restrict CPVC in certain applications
- ✗May have slight plastic taste initially
Frequently Asked Questions
What is the C-value for CPVC pipe?
CPVC pipe has a Hazen-Williams C-value of 150, identical to PVC and PEX. This provides excellent flow characteristics for both hot and cold water applications.
What's the difference between CPVC and PVC?
CPVC is chlorinated PVC, giving it higher temperature resistance (180°F vs 140°F). CPVC can be used for hot water, while standard PVC is only for cold water and drainage. Both have the same C-value (150) and flow characteristics.
Can CPVC be used for hot water recirculation?
Yes, CPVC is excellent for hot water recirculation systems. It handles continuous 180°F temperatures and maintains good flow characteristics. Use our Hot Water Recirculation Calculator to properly size CPVC for recirculation systems.
How do I join CPVC pipe?
CPVC uses solvent welding with special CPVC cement (not PVC cement). The process involves cleaning, priming, and applying cement to both surfaces before joining. CPVC can also use mechanical fittings in some applications.
Code Compliance
CPVC is approved by IPC and UPC for hot and cold water supply. Some jurisdictions may have restrictions on CPVC for certain applications. Always use CPVC-rated fittings and cement - never mix with PVC materials. Verify local code requirements before installation.
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