C900 PVC pipe is a type of polyvinyl chloride (PVC) pressure pipe manufactured in compliance with the American Water Works Association (AWWA) Standard C900. This standard specifies requirements for PVC pipes used in potable water distribution systems, reclaimed water systems, and sewer applications. C900 pipes are known for their durability, corrosion resistance, and cost-effectiveness, making them a popular choice for municipal infrastructure projects.
1. Composition and Material Properties
1.1 PVC Material
C900 pipes are made from Type 1, Grade 1, unplasticized polyvinyl chloride (PVC), commonly referred to as PVC 1120. This material is chosen for its high strength, resistance to chemicals, and suitability for pressure applications.
1.2 Physical Properties
| Property | Value |
|---|---|
| Specific Gravity | 1.40 |
| Tensile Strength | 7,000 psi |
| Tensile Modulus | 400,000 psi |
| Hydrostatic Design Stress | 2,000 psi |
Source: AWWA C900 Standard
2. Pressure Ratings and Design
2.1 Pressure Classes
C900 pipes are available in various pressure classes, which denote the pipe’s ability to withstand internal water pressure. The Pressure Class (PC) is determined by dividing the long-term hydrostatic strength by a safety factor of 2. Common pressure classes include:
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PC 165: Suitable for lower pressure applications.
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PC 235: Commonly used in municipal water systems.
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PC 305: Designed for higher pressure requirements.
2.2 Dimension Ratios (DR)
The Dimension Ratio (DR) is the ratio of the pipe’s average outside diameter to its minimum wall thickness. Common DRs for C900 pipes include DR 25, DR 18, and DR 14. A lower DR indicates a thicker wall and higher pressure rating.
2.3 Safety Factors
C900 pipes are designed with a safety factor of 2.5, meaning the pipe is tested to withstand pressures up to 2.5 times its rated pressure class. This ensures reliability under varying operational conditions.
3. Applications
3.1 Potable Water Distribution
C900 pipes are widely used for the distribution of potable water due to their corrosion resistance and long service life. They are suitable for both underground and above-ground installations.
3.2 Reclaimed Water Systems
In reclaimed water systems, C900 pipes are employed to transport treated wastewater for non-potable uses, such as irrigation and industrial processes.
3.3 Sewer Systems
C900 pipes are also utilized in gravity sewer systems and force mains, offering durability and resistance to aggressive environments.
4. Advantages
4.1 Corrosion Resistance
Unlike metal pipes, C900 PVC pipes do not corrode when exposed to water and soil, leading to a longer service life and reduced maintenance costs.
4.2 Smooth Interior Surface
The smooth interior surface of C900 pipes minimizes friction, reducing energy consumption in pumping systems and maintaining flow efficiency over time.
4.3 Lightweight and Easy Handling
PVC’s lightweight nature makes C900 pipes easier to transport and handle during installation, potentially lowering labor costs.
4.4 Cost-Effectiveness
The combination of durability, low maintenance, and ease of installation makes C900 pipes a cost-effective choice for many applications.
5. Comparison with Other PVC Standards
| Feature | C900 PVC Pipe | C905 PVC Pipe | Ductile Iron Pipe |
|---|---|---|---|
| Size Range | 4″ to 12″ | 14″ to 48″ | 3″ to 64″ |
| Pressure Ratings | PC 165 to PC 305 | Higher pressure ratings | Up to PC 350 |
| Safety Factor | 2.5 | 2.0 | 2.0 |
| Corrosion Resistance | Excellent | Excellent | Moderate |
| Installation Ease | High | Moderate | Low |
| Cost | Lower | Higher | Higher |
6. Maintenance and Longevity
C900 pipes require minimal maintenance due to their resistance to corrosion and scaling. Regular inspections are recommended to ensure joints remain secure and to check for any external damage. With proper installation and maintenance, C900 pipes can have a service life exceeding 50 years.
7. Installation Guidelines
7.1 Bedding and Backfill
Proper bedding and backfill materials are essential to prevent pipe deformation and ensure long-term performance. Granular materials are typically used to provide uniform support.
7.2 Joint Assembly
C900 pipes often utilize gasketed joints that conform to ASTM F477 and D3139 standards. These joints are designed for easy assembly and to provide a watertight seal.
7.3 Handling Precautions
During transportation and installation, care should be taken to avoid dropping or striking the pipes, as this can cause damage. Proper lifting techniques should be employed to prevent stress on the pipe material.
8. Environmental Considerations
PVC is a recyclable material, and efforts should be made to recycle C900 pipes at the end of their service life. Additionally, the production of PVC pipes has a lower environmental impact compared to some other materials, such as ductile iron.
9. Frequently Asked Questions (FAQs)
9.1 What is the difference between C900 and C905 pipes?
C900 pipes are designed for smaller diameter applications (4″ to 12″), while C905 pipes are intended for larger diameters (14″ to 48″). Both are PVC pressure pipes, but C905 pipes typically have higher pressure ratings and a different safety factor.
9.2 Can C900 pipes be used for both potable and non-potable water?
Yes, C900 pipes are suitable for both potable water distribution and non-potable applications, such as reclaimed water systems and sewer lines.
9.3 How do C900 pipes compare to ductile iron pipes in terms of cost?
C900 PVC pipes are generally more cost-effective than ductile iron pipes due to lower material and installation costs. However, ductile iron pipes may be preferred in certain applications requiring higher pressure ratings.
9.4 What is the typical service life of C900 pipes?
With proper installation and maintenance, C900 pipes can have a service life exceeding 50 years.
9.5 Are there any environmental concerns with using PVC pipes?
While PVC is a recyclable material, the production of PVC pipes involves the use of chlorine and other chemicals. Efforts should be made to recycle PVC pipes at the end of their service life to minimize environmental impact.
9.6 How should C900 pipes be stored before installation?
C900 pipes should be stored on a flat surface, away from direct sunlight and heat sources, to prevent warping. They should be kept clean and free from debris to ensure proper joint assembly during installation.
Conclusion
C900 pipes offer a reliable and cost-effective solution for various piping applications, particularly in municipal water systems. Their durability, resistance to corrosion, and ease of installation make them a preferred choice for many infrastructure projects. Understanding the specifications, applications, and maintenance requirements of C900 pipes is essential for ensuring their optimal performance and longevity.
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