First level depressurization: Reduce the high pressure (e.g. 15 MPa) inside the gas cylinder to a stable, lower medium pressure (e.g. 0.5-0.8 MPa).
Secondary pressure reduction and stabilization: When you adjust the knob of the flowmeter, the pressure regulator ensures stable output pressure and flow rate, even if the cylinder pressure gradually decreases with use, it can maintain a constant flow rate.
So, the entire gas path is:
High pressure gas cylinder (~15 MPa) → pressure reducer (reduces pressure to~0.8 MPa) → flow meter (controls flow under safe pressure) → welding gun
summary
The argon flowmeter itself does not control pressure, it controls flow rate (L/min).
The input pressure at which a flowmeter can operate normally is usually determined by the pressure regulator in front of it, and this pressure is generally stable at around 0.5-0.8 MPa.
The maximum pressure (safety limit) that the flowmeter itself can withstand is usually about 1.0 MPa. This value is much lower than the pressure of the gas cylinder, so it is absolutely forbidden to directly connect the flowmeter to the high-pressure gas cylinder.
The component that truly controls and withstands the high pressure of the gas cylinder is the pressure reducer. The pressure regulator is equipped with a high-pressure gauge, which displays the pressure inside the bottle.
Simple answer: During welding, the pressure at the inlet of the argon flowmeter is usually controlled below 0.8 MPa by a pressure reducer, which is its normal operating pressure range. The maximum safe pressure that the flowmeter itself can withstand is about 1.0 MPa.