Which of the following equipment is necessary for conducting service testing of fire hoses?

The essential equipment for conducting service testing of fire hoses includes nozzles with shutoff valves. When testing hoses, especially for service tests, it’s important to control the flow of water being discharged. Nozzles with shutoff valves allow the tester to create a controlled environment, enabling the measurement of pressure and ensuring that the hose’s integrity can be assessed without unintentional fluctuations in water flow.

The use of shutoff valves also enables the tester to simulate real-life scenarios, effectively examining the hose's performance under expected conditions. By controlling water discharge, the tester can more accurately determine if the hose can withstand the required pressure levels and identify any leaks or weaknesses in its construction.

The other equipment listed, while useful in different contexts related to fire service operations, does not specifically address the essential requirements for service testing hoses. Flow meters are used for measuring the flow of water but are not necessary for testing hose strength. Hydraulic jacks are typically employed for lifting heavy objects and are unrelated to hose testing. Pressure gauges are indeed important, but in this context, the primary equipment directly responsible for managing and monitoring the flow during testing is the nozzle with shutoff valves.