Anyone know where should the needle be set at for inlet pressure and outlet pressure by looking at this gauge picture

[jk9761]

Anyone know where the needle in this picture should be set at for inlet pressure and outlet pressure by looking at this picture . 250kfg/cm2 10kfg/cm2 . i know the flow meter is shown here so does it really matter what pressure the gauge is reading if the flowmeter controls the airflow to be 15 liters per minute.

 

[Greenberg]

Inlet pressure = 20MPa (max)
Outlet pressure = 0.4MPa (max)
Flow rate = 15LPM for N2

 

[jk9761]

Inlet pressure = 20MPa (max)
Outlet pressure = 0.4MPa (max)
Flow rate = 15LPM for N2

thanks alot .