Gas Technician 3 (G3) License Practice Exam

The actual pressure drop in a gas line is calculated by taking the difference between the working pressure at the gas meter and the working pressure at the appliance. This approach directly measures how much pressure is lost as the gas travels through the line, providing a clear understanding of the efficiency and performance of the gas delivery system.

In practical terms, when gas flows from the meter to the appliance, it experiences resistance due to the piping, fittings, and any appliances connected along the way. By subtracting the appliance's working pressure from that at the meter, you obtain a precise value for this pressure drop, which is essential for ensuring the system operates safely and efficiently.

This method also helps to diagnose issues such as leaks, blockages, or other anomalies that can affect the performance of the gas system. Calculating the pressure drop accurately allows technicians to assess potential problems and make necessary adjustments or repairs to maintain proper operation.