When should pitot gauges be used during service tests?

Using pitot gauges during service tests is essential for accurately measuring the water flow and pressure at various points in a fire apparatus's nozzle and ensuring that the system operates effectively and safely. The best practice for utilizing pitot gauges is to have them fixed or secured to a nozzle. This allows for consistent and reliable readings during the test, as the gauge will not be affected by movement or external forces, which could impact the accuracy of the flow measurement.

Securing the gauge ensures that it is properly aligned with the water stream, facilitating accurate pressure readings that are vital for determining the nozzle’s performance and flow rate. Proper alignment with the water stream is crucial in these tests to ensure that the data collected reflects the actual flow performance under simulated conditions.

The other methods described do not provide the same level of accuracy and reliability. Manually holding the gauge could introduce variability due to movement or improper positioning. Using it in zero pressure conditions would not yield meaningful data, as there would be no flow or pressure to measure. Attaching it to a hose reel, instead of directly to the nozzle, may not result in accurate pressure readings related to the nozzle’s performance, as the pressure at the hose reel can differ from that at the nozzle due to friction loss and other factors