CSLB C-27 Landscaping ContractorIrrigation SystemsMedium
A C-27 contractor is preparing to repair a section of a 1-inch PVC lateral line that has been damaged by tree roots. The system is designed for a typical residential landscape. What type of PVC pipe is most commonly used for lateral lines in such applications, considering pressure ratings and flexibility?
- ASchedule 40 PVC
- BClass 200 PVC
- CClass 315 PVC
- DSchedule 80 PVC
Show answer & explanationAnswer & explanation
Correct answer: B. Class 200 PVC
Class PVC (e.g., Class 200) is commonly used for lateral lines because it has thinner walls and is more flexible than Schedule PVC, making it easier to install and less prone to breakage from ground movement, while still providing adequate pressure rating for typical lateral line pressures (often 30-50 PSI). Schedule 40 is more rigid and often used for main lines, while Schedule 80 and Class 315 are for higher pressure or structural applications.
Why the other options are wrong
- A. Schedule 40 PVC is thicker and more rigid, often used for main lines or where higher pressure/strength is needed, but less flexible for laterals.
- C. Class 315 PVC has a very high-pressure rating and thicker walls, making it overkill and less flexible for typical residential lateral lines.
- D. Schedule 80 PVC is very thick-walled and rigid, typically used for high-pressure industrial applications or structural purposes, not residential laterals.
Lateral Line PVC Type
Class PVC (e.g., Class 200) is typically used for irrigation lateral lines due to its balance of pressure rating and flexibility, aiding installation and resisting ground stress.
- Class PVC is thinner-walled and more flexible than Schedule PVC.
- Schedule PVC is thicker, more rigid, and for higher pressure/main lines.
- Lateral lines operate at lower pressures than main lines.
Memory trick: Lateral for Class, Main for Schedule's mass.