What provides an indication of pressure downstream from regulators in gas supply systems?

A pressure gauge is essential in gas supply systems as it provides a direct indication of the pressure downstream from regulators. This is crucial for monitoring the performance and safety of the gas delivery system. By displaying real-time pressure readings, the pressure gauge enables personnel to ensure that the pressure is within the desired range for the specific application, whether for medical or industrial uses. This information helps in identifying any issues that might arise, such as pressure drops that could indicate leaks or malfunctions in the system.

In the context of the other components mentioned, a switching valve is primarily used to redirect gas flow between different lines or sources, while a relief valve functions to prevent excessive pressure build-up by releasing gas when it exceeds predetermined levels. On the other hand, a flow meter measures the volume of gas passing through a system but does not provide direct pressure readings. Thus, while all these components play important roles in gas supply systems, the pressure gauge is specifically designed to monitor downstream pressure, making it the correct choice in this context.