The unthreaded portion of gas piping outlets shall extend a minimum of how many inches above the surface of floors?

The correct answer is that the unthreaded portion of gas piping outlets must extend a minimum of 2 inches above the surface of floors. This requirement is outlined in the National Fuel Gas Code to ensure safety and accessibility. By having the unthreaded portion elevated, it reduces the risk of damage from objects or equipment that may be on the floor. Moreover, this height helps in preventing any potential leaks or gas accumulation at floor level, which could lead to hazardous situations.

In terms of practical application, the designated height also facilitates the proper installation of appliances and connections while ensuring compliance with safety standards. The height serves as a precautionary measure to ensure that gas lines are not easily disturbed or impacted by cleaning activities or movement of objects, thereby enhancing the overall safety of gas installations.