CO2 gauge question

I picked up a CO2 tank and gauge. I have read that one should run the flow based on the size of the container. However, the outflow gauge is in PSI not LPM. Should I get a new gauge or use the PSI, but it there some type of conversion?

Feel free to PM me. Thanks!

Google: " Conversion tables for CO 2, from PSI to LPM"

Not sure this helped.