If you were checking for flow over a relief valve, which instrument would you use?

When checking for flow over a relief valve, using a flow meter on the outlet side of the relief valve is the most effective method. This instrument directly measures the flow rate of the fluid being discharged from the valve, allowing you to assess whether the relief valve is functioning correctly and providing adequate protection against overpressure.

The flow meter provides precise quantitative data that can confirm if the valve opens at the predetermined set pressure and allows for the expected flow rate. It indicates if the valve is discharging too little or too much fluid, ensuring the system operates safely and efficiently.

Other instruments, like temperature gauges and pressure gauges, serve important functions but do not directly measure the flow rate, which is critical in this scenario. Flow control at the actuator inlet also does not provide the necessary data on the relief valve's performance regarding flow discharge. Thus, the flow meter is the most suitable instrument for monitoring the flow characteristics of a relief valve.