Discover the versatility of SCH 20 PVC, a popular choice for lightweight plumbing and DIY projects. Known for its affordability and ease of installation, SCH 20 PVC is ideal for homeowners and hobbyists seeking reliable piping solutions. This guide will help you understand its key features, uses, and tips for selecting the right products for your next project.
Schedule 20 PVC: Types, Variations, and Key Applications
| Pipe Type | Nominal Sizes | Wall Thickness | Working Pressure | Common Uses | Color | Availability |
|---|---|---|---|---|---|---|
| Sch 20 PVC | 1/2″ – 12″ | 1.73 – 4.57 mm | Up to 200 psi | Drainage, irrigation, dust collection | White | Common in stores |
| Class 200 PVC | 1/2″ – 12″ | Varies | 200 psi | Water supply, irrigation | White | Often special order |
| Sch 40 PVC | 1/2″ – 24″ | Thicker than Sch 20 | Up to 450 psi | Water supply, pressure lines | White/Gray | Widely available |
| Sch 80 PVC | 1/2″ – 24″ | Thickest wall | Up to 800 psi+ | Industrial, high pressure | Dark gray | Select outlets |
Values are approximate & may vary by manufacturer
Everyday Usage of Schedule 20 PVC
Schedule 20 (Sch 20) PVC pipe is a polyvinyl chloride piping solution known for its thin walls, light weight, and cost-efficiency. It is widely used in a range of low-pressure and non-pressurized applications. Here are common uses that highlight its versatility:
- Residential and Commercial Drainage: Perfect for gravity-fed drain systems in yards, basements, and foundations because of its ease of installation and light structure.
- Irrigation and Sprinkler Lines: Used extensively in above-ground and underground irrigation, including golf courses and sports fields where pressure levels remain moderate.
- Dust Collection Systems: Popular among hobbyists and professionals in woodworking or workshops for creating dust collection ductwork due to the larger internal diameter compared to Sch 40 or Sch 80, making it less likely to clog.
- Pool & Spa Piping: Used for non-pressurized pool overflow or waste lines.
- HVAC and Ventilation: Suitable as return air ducts or for venting systems that do not experience high pressure or major temperature swings.
- Protective Sleeving: Often acts as a conduit for electrical wiring or as a sleeve to protect shallow water lines.
Where NOT to Use Sch 20 PVC
- Pressurized Water Supply Lines: Its relatively thin wall makes Sch 20 unsuitable for high-pressure potable water delivery.
- High-Temperature Applications: Not rated for hot water, steam, or any situations with temperature extremes.
Benefits of Sch 20 PVC Pipe
1. Lightweight and Easy to Handle
Sch 20 PVC’s thin walls make the pipe significantly lighter than heavier schedule types. This leads to easier transportation, handling, and quicker installation—especially for DIY users or large-scale projects.
2. Cost-Effective
Because it requires less material, Sch 20 PVC is generally the most economical choice for non-pressurized or low-pressure pipework.
3. Resistance to Corrosion and Chemicals
Like all PVC, Schedule 20 is resistant to rust, scaling, and chemical corrosion, which ensures longevity even in harsh soil or water conditions.
4. Flexibility
Its relatively high flexibility (compared to thicker-wall pipes) means it can accommodate minor ground shifts without cracking, making it ideal for landscaping drains.
5. Smooth Interior Wall
The smooth interior of Sch 20 PVC reduces friction losses in fluid, air, or dust transport, maximizing efficiency and minimizing the risk of buildup inside the pipe.
How to Choose the Right Sch 20 PVC Pipe
Selecting the correct Sch 20 PVC pipe requires attention to your project’s requirements and understanding the product’s attributes.
1. Define the Application
- Drainage: Choose diameter based on the flow volume—common sizes are 3”, 4”, and 6” for residential drainage.
- Dust Collection: Use larger diameters (such as 4″ or 6″) for main trunk lines to reduce clogging; smaller sizes for tool branches.
- Irrigation: Ensure the operating pressure will not exceed the maximum allowed for Sch 20 (typically under 200 psi; confirm project specifics).
2. Size and Length
- Pipes are available in diameters from 1/2” up to 12” (occasionally larger by special order).
- Standard lengths are 10’ and 20’ sticks, but many retailers will cut to size.
- Consider purchasing “belled end” or coupler pipes to simplify joining.
3. Fittings & Compatibility
- Verify fittings match Sch 20’s dimensions; Sch 20 pipe is NOT always compatible with Sch 40 or Class 200 fittings due to wall thickness and outside diameter differences.
- Use manufacturer-specified couplers, elbows, T-joints, and adapters.
4. Pressure and Temperature Ratings
- Do not use for applications exceeding its pressure or temperature limits. For anything above 100-150 psi, choose Sch 40 or higher.
5. Local Building Codes
- Always verify that Sch 20 is approved for your intended use according to regional plumbing codes—some municipalities restrict its use for specific building applications.
Practical Tips and Best Practices
Handling and Storage
- Store pipes in a well-ventilated, shaded area to prevent UV degradation.
- Stack pipes carefully to avoid bending or warping.
- Inspect for cracks or damage before installation.
Installation
- Lay pipes with a consistent slope for gravity drainage to prevent standing water.
- Use appropriate adhesives or approved mechanical couplers for secure joints; follow cure times for solvent cement.
- For underground installations, bed the pipe in a layer of sand to prevent point loads or sharp rocks from causing punctures.
Maintenance
- Periodically flush drainage or dust collection pipes to prevent sediment or dust buildup.
- Check visible joints and connections for leaks or shifting, especially after freeze-thaw cycles.
- Replace cracked or brittle sections as needed; cutting and joining replacements is straightforward.
Joining Methods
- Solvent cement (“gluing”) is the standard joining method for Sch 20 PVC, ensuring a strong, watertight, and permanent connection.
- For inspection access or future modifications, consider installing clean-outs or removable unions at strategic points.
Technical Comparison Table: Sch 20 vs. Sch 40 vs. Class 200 PVC
| Attribute | Sch 20 PVC | Sch 40 PVC | Class 200 PVC |
|---|---|---|---|
| Nominal Sizes | 1/2″ – 12″ | 1/2″ – 24″+ | 1/2″ – 12″ |
| Wall Thickness | 0.065″ (2″) – 0.120″ (4″) | 0.154″ (2″) – 0.237″ (4″) | Varies; based on pressure |
| Pressure Rating | Up to 200 psi (max) | 220–450 psi (varies size) | 200 psi |
| Weight (per 10’ stick) | ~8–25 lbs | ~12–35 lbs | Similar to Sch 20 |
| Color | Usually white | White (also gray) | White |
| Applications | Non-pressurized drains, dust | Pressurized water, drains | Water, irrigation |
| Cost (relative) | Lowest | Moderate | Moderate |
| Compatibility | Special fittings needed | Sch 40 fittings | Sometimes matches Sch 20 |
| Typical Lengths | 10’–20’ | 10’–20’ or custom | 10’–20’ |
| Temperature Limit | Up to 140°F (60°C) | Up to 140°F (60°C) | Up to 140°F (60°C) |
Conclusion
Schedule 20 PVC pipe is an excellent choice for many light-duty plumbing, irrigation, drainage, and shop applications, thanks to its affordability, lightweight nature, and ease of use. However, it’s crucial to understand its limitations regarding pressure and temperature and to ensure compatibility with your project’s requirements and local codes.
By choosing the right size and fittings, handling and installing pipes properly, and performing routine maintenance, you can expect reliable performance from your Sch 20 PVC system. Always prioritize safety and compliance, and consult professionals for complex installations, especially those involving water supply, pressurized systems, or municipal infrastructure.
FAQ
-
What does “Schedule 20” actually mean for PVC pipe?
“Schedule 20” refers to a standardized wall thickness for PVC pipe that is thinner than Schedule 40 or 80. Schedules indicate wall thickness, which impacts the pipe’s strength and pressure tolerance. -
Can I use Sch 20 PVC for drinking water or pressurized supply lines?
No, Sch 20 is generally not approved or recommended for potable or pressurized water supply lines due to its low pressure rating and thinner wall, which can fail under higher stresses. -
What are the most common sizes available for Sch 20 PVC?
Typical sizes range from 1/2 inch to 12 inches in diameter, with 3″, 4″, and 6″ being the most popular for drainage and dust collection. -
Is Sch 20 PVC safe to use underground?
Yes, it can be buried for drainage or low-pressure applications, but ensure it is properly bedded to prevent punctures, and avoid using it beneath heavy traffic or where high-pressure water is present. -
How do I join Sch 20 PVC pipes together?
Pipes and compatible fittings are usually joined with solvent cement (“PVC glue”), which chemically bonds the components. Always clean and dry the surfaces before applying cement for a leak-free connection. -
What’s the difference between Schedule 20 and Class 200 PVC?
Class 200 refers to a specific pressure rating (200 psi), while Schedule 20 refers to wall thickness. While both may sometimes have similar applications, they are not interchangeable—always check pressure and dimension compatibility. -
Can Sch 20 pipe be used for dust collection in a woodworking shop?
Absolutely. Its smooth interior and larger diameter for a given OD, plus lightweight construction, make it ideal for DIY and small commercial dust collection systems. -
Will Schedule 20 pipe fit with Schedule 40 fittings?
Not always. Due to different wall thicknesses and dimensions, they may not be compatible. Use fittings expressly made for Sch 20 or verify compatibility before purchase. -
Is Sch 20 PVC UV resistant?
While PVC is somewhat UV resistant, prolonged sunlight exposure can make it brittle and discolored. For outdoor applications, paint the pipe with a non-dark latex paint or provide UV shielding. -
How do I maintain or clean Schedule 20 PVC pipe?
Flush pipes periodically for drainage or dust collection systems. Visually inspect joints for leaks, and replace or repair any cracked sections as needed. Use soft cleaning tools to prevent scratching or abrasion.
This in-depth guide should give you the confidence to assess, select, and use Schedule 20 PVC for a wide range of DIY, commercial, or industrial projects. Make sure to match your selection to your specific needs, and enjoy the versatility and simplicity Sch 20 PVC has to offer.