What size should the branch outlet be in relation to the main supply line?

The appropriate size for the branch outlet in relation to the main supply line is the same size. This requirement ensures that there is no restriction in gas flow, which is crucial for maintaining adequate and consistent pressure in the system. When the branch outlet is the same size as the main supply line, it allows for a smooth transition of gas, minimizing pressure losses and ensuring that appliances receive the necessary amount of gas for optimal performance.

In gas piping design, maintaining proper sizing throughout the system is critical for safety and efficiency. If the branch outlet were smaller, it could lead to reduced gas delivery to appliances, potentially causing them to operate inefficiently or not at all. Conversely, if the branch outlet were larger than the main line, it might create uneven pressure distribution or even allow for sediment or liquid gas accumulation, which could pose operational issues or safety hazards.

The requirement that the branch outlet be the same size as the main supply line is a key principle in gas system design, ensuring reliability and compliance with safety standards outlined in the National Fuel Gas Code.