Should always be used when working with nitrogen?

• A. Thermocouple
• B. Regulator
• C. Flowmeter
• D. Pressure Relief Valve

Answer: (B)

Controlling shielding gas from a nitrogen cylinder requires a device that can safely reduce the high cylinder pressure to a usable level and provide adjustable flow. That function is performed by a regulator. Cylinder pressures are very high, and the regulator brings that pressure down to a stable, controllable output so you can set the shielding level you need for brazing without blasting gas at full cylinder pressure. It also typically includes gauges to show the output pressure, helping you maintain a consistent shielding environment.

Without a regulator, gas would be released at unpredictable, potentially dangerous pressures, making it hard to control the atmosphere around the joint and risking equipment damage or unsafe operation. A flowmeter by itself measures flow but does not reduce pressure or regulate it, so it can’t substitute for a regulator. A pressure relief valve is a safety device that vents excess pressure if something goes wrong, but it isn’t used for normal, steady control of shielding gas. A thermocouple measures temperature, not gas flow or pressure.