What is the minimum length required for a drip or dirt leg in gas piping?

The minimum length required for a drip or dirt leg in gas piping is 1 inch minimum hub to hub. This specification is crucial because a drip or dirt leg serves a vital function in gas piping systems by collecting condensate and debris that can accumulate in the lines. If the leg is too short, it may not adequately perform its function and could lead to issues such as blockages or corrosion within the piping system.

By having a minimum length of 1 inch, it ensures that there is enough space for the liquid and other materials to settle without interfering with the gas flow. This helps maintain the integrity and efficiency of the gas delivery system. Code compliance also plays a significant role, as it ensures safety and reliability during operation, taking into account the size and potential impact on gas flow parameters.

The other choices suggest lengths that are longer than necessary for the purpose of a drip leg, which could be excessive in many applications, while the option indicating any length is acceptable does not adhere to established safety and operational standards.