Where must a device be installed in the CNG piping of an automatic dispenser?

Answer: C — On the downstream side of the device

The correct choice emphasizes that the device, typically a flow meter or safety valve, must be installed on the downstream side of the automatic dispenser. This is crucial for accurate measurement and control of the flow of compressed natural gas during fueling operations. Installing the device downstream ensures that it monitors the flow after the pressure and volume have been regulated, providing precise data that are essential for safe operation and compliance with regulatory standards. This placement also minimizes the risk of any interference from upstream factors that could affect the functioning of the device, ensuring safety and efficiency in the CNG dispensing process.