Which of the following is NOT included in the PDI's of Water Glycol?

The correct answer identifies a component that is not part of the Pressure Differential Indicator (PDI) requirements for Water Glycol systems. The PDI is used to monitor the performance and safety of a system, ensuring that essential conditions are met for efficient operation.

Stowage, quantity, and the integrity of the wire seal on the handle are critical for managing and maintaining the safety of the Water Glycol fluid. Stowage refers to how the fluid is stored safely and properly, ensuring that it doesn’t lead to leaks or contamination. The quantity indicates how much fluid is available for use, while the wire seal ensures that the fluid remains secure and prevents tampering or leakage.

In contrast, a pressure gauge is crucial in many systems to measure and display the pressure level, but it does not pertain to the specific indicators associated with PDI for Water Glycol. Therefore, since the pressure gauge does not fall under the stated categories of stowage, quantity, or seal integrity, it is correctly identified as the component that is not included in the PDI's of Water Glycol.