We have been experience nitrogen issues and believe the issue may be the gas flow module on our 6550 qTOF. When the instrument is vented and powered off, a high flow of N2 persists from the drying gas port to the source. N2 flow to the drying gas port does not persist on our 6460 qqq when vented and powered off. The gas flow modules look nearly identical on the two instruments. Is it normal for N2 to flow to the drying gas port on the 6550 when powered off? Please advise. Thank you!