TD2K, thanks for your help. I was hoping to find a formula to put in a spreadsheet. BTW, what section of Perry's are these charts. I couldn't find it. Thanks.
I am not an engineer, so forgive my ignorance. I need to know if there is a formula for determining the delta T when taking a pressure drop across a valve. Specifically, what information do I need other than the inlet/outlet pressures, specific gravity (this is natural gas) and inlet...