Also, use a new copper washer every time the line is removed and reinstalled. The soft copper gets several lines engraved in it from concentric circles on the mating flange of the hose, and it's virtually impossible to engage the same grooves twice. Re-using a washer usually ends up with a seep leak and then a stripped thread or a broken fitting while trying to stop the leak by tightening it repeatedly.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!