Hi- A recently installed natural gas main is showing evidence of water infiltration. Water is getting into the customers regulator and meter and freezing. The gas main was cleaned and "pigged" after the installation. The system is currently operating at an MAOP of 60 PSIG natural gas. When the main was pressure tested (at 90 PSIG - air) it is likely that water (in the form of vapor) got into the main from the compressed air (Air compressor). Using a Psychometric chart I was able to calculate the amount of water at atmospheric conditions (14.7 PSIA). I assumed the Dry Bulb temp was 32 Deg, RH = 99%... etc.. Cameup with 9 lbs. How would I calculate the water infiltration at 90 PSIG Air? I think I need to use partial pressure? Any help would be greatly appreciated!