Red Seal Plumbing Complete 2026 Practice Exam

In this scenario, having a standing pressure of 7 inches w.c. and an operating pressure of 5.9 inches w.c. indicates a significant difference between the two measurements. The standing pressure represents the maximum pressure available in the system when no gas is being drawn, while the operating pressure reflects the actual pressure during usage.

When the operating pressure is significantly lower than the standing pressure, it typically suggests that the gas line may not be able to supply sufficient gas to meet demand. Specifically, if the operating pressure drops below what is necessary for proper appliance functioning, it can be an indicator that the gas line is undersized. An undersized gas line cannot accommodate the required volume of gas, leading to this lower operating pressure.

Furthermore, if there were a leak present in the system, one would generally expect the operating pressure to be notably lower than the standing pressure due to the loss of gas. While this could point to the possibility of a leak, it does not directly conclude that the gas line is functioning properly in terms of size.

In contrast, if a regulator were faulty, one would typically see more erratic pressure readings and failures to maintain consistent pressure, rather than just a consistent drop in the operating pressure.

Thus, based