CSLB C-36 Plumbing ContractorRough-in PlumbingMedium
A plumbing contractor is installing a new residential gas piping system. The gas line passes through a concrete foundation wall. To prevent damage to the pipe, what is the minimum annular space required around the gas pipe where it passes through the sleeve in the foundation wall, according to the California Plumbing Code (CPC)?
- A1/2 inch
- B1 inch
- C1/4 inch
- D2 inches
Show answer & explanationAnswer & explanation
Correct answer: A. 1/2 inch
When gas piping passes through a foundation or structural wall, a sleeve is required to protect the pipe. The California Plumbing Code mandates a minimum 1/2-inch annular space between the pipe and the sleeve to allow for movement and prevent corrosion.
Why the other options are wrong
- B. 1 inch is often specified for larger diameter pipes or specific applications, but not the minimum for all gas piping.
- C. 1/4 inch is too small and does not provide adequate clearance for movement or protection.
- D. 2 inches is excessive and not a standard minimum requirement for this application.
Gas Pipe Annular Space (Sleeve)
The minimum clear distance required between a gas pipe and its protective sleeve when passing through a structural element, allowing for movement and preventing damage.
- Protects against differential settlement.
- Prevents corrosion from contact with concrete.
- Required by plumbing codes (e.g., CPC).
Memory trick: Sleeves Securely Separate Structures.