CSLB C-36 Plumbing ContractorRough-in PlumbingEasy
A plumbing contractor is installing a new residential gas piping system. The gas meter is located outside the building, and the main gas line enters through the exterior wall. What is the maximum unsupported length permitted for a 1-inch rigid gas piping installed horizontally, without additional hangers or supports?
- A8 feet
- B10 feet
- C6 feet
- D12 feet
Show answer & explanationAnswer & explanation
Correct answer: B. 10 feet
According to the California Plumbing Code (CPC), 1-inch rigid gas piping installed horizontally can have a maximum unsupported length of 10 feet. Larger pipes allow longer spans, while smaller pipes require more frequent support.
Why the other options are wrong
- A. This is not a standard maximum unsupported length for 1-inch rigid gas piping.
- C. This is typically the maximum unsupported length for 1/2-inch or 3/4-inch rigid gas piping.
- D. This is typically the maximum unsupported length for 1 1/4-inch or 1 1/2-inch rigid gas piping.
Horizontal Gas Pipe Support
The maximum allowed distance between hangers or supports for horizontal rigid gas piping.
- Prevents sagging and stress on joints.
- Varies based on pipe material and diameter.
- Ensures system stability and safety.
Memory trick: Support your gas lines, or they'll sag like a tired old rope.