Which statement about regulator sizing is true?

• A. Flow charts are used to size regulators
• B. Pressure gauges are used to size regulators
• C. Thermal diagrams are used to size regulators
• D. Color codes determine regulator size

Answer: (A)

Sizing a regulator is about matching its flow capacity to the gas demand of the system. Flow charts from regulator manufacturers show how much gas the regulator can deliver at different outlet pressures and inlet pressures, so you can pick a regulator whose flow capacity covers the required demand for your tools and setup. Pressure gauges tell you what the downstream pressure is, not how much gas the regulator can pass, so they don’t determine size. Thermal diagrams and color codes don’t indicate regulator capacity. So, flow charts are the tool used to size regulators.