Final answer:
Gas piping in a concrete slab must be sleeved and vented, option B. This ensures protection against damage and corrosion and prevents gas accumulation. Unsleeved pipes, especially with Cu/Fe joints, are prone to corrosion, so long-term planning is crucial.
Step-by-step explanation:
When considering gas piping running in a concrete slab, it's important to note that the piping must adhere to specific safety guidelines to prevent potential hazards. The correct answer to whether gas piping can be buried in a concrete floor is B. Must be sleeved and vented. This is because gas piping requires protection from potential damage and corrosion that could occur when in contact with concrete and other materials. Moreover, the sleeve ensures that there's a protective barrier between the pipe and slab, while venting prevents the accumulation of any gas that might escape from the pipe, mitigating the risk of explosion or health hazards.
Furthermore, burying unsleeved gas piping directly in concrete could indeed lead to corrosion over time, especially if there are Cu/Fe pipe joints. These types of joints can be susceptible to galvanic corrosion, a process that is accelerated when different metals are in contact in the presence of an electrolyte, which could be moisture in the concrete.
Answer a suggests that such a setup should only be considered if selling the house soon, likely due to the potential for rapid corrosion. While this approach is not recommended for long-term durability and safety, it highlights the risks associated with mixing different metals in pipeline construction.