CSLB C-36 Plumbing ContractorRough-in PlumbingMedium
A plumbing contractor is installing a new gas piping system in a commercial building. The gas line passes through a concrete slab. To prevent corrosion and damage, the gas piping must be provided with an annular space and sealed at the penetration. What is the minimum annular space required around the gas pipe where it passes through the concrete slab?
- A1 inch
- B1/4 inch
- C1/2 inch
- D3/4 inch
Show answer & explanationAnswer & explanation
Correct answer: C. 1/2 inch
According to the California Plumbing Code (CPC), where gas piping passes through a concrete slab, it must be protected by a sleeve with an annular space of not less than 1/2 inch around the pipe. This space allows for pipe expansion/contraction and protection.
Why the other options are wrong
- A. This annular space is larger than required by code, potentially leading to unnecessary material use or sealing challenges.
- B. This annular space is too small and does not meet code requirements for this application.
- D. While providing good protection, this is not the minimum required by code; 1/2 inch is sufficient.
Gas Pipe Slab Penetration
Requirements for protecting gas piping where it passes through concrete slabs, including sleeving and annular space.
- Prevents pipe corrosion from concrete contact.
- Allows for thermal expansion/contraction.
- Ensures structural integrity of the pipe.
Memory trick: Through concrete, gas needs space; a half-inch gap keeps it safe in its place.