R134a Can Orientation

In what orientation should you hold a can of 134a while recharging your A/C? Most websites/directions say right-side-up (charging as a gas) but the can's directions say upside down (letting liquid flow into the system). Which is right?

Thanks,
-k

Go by the can's directions. Some of the cans have oil in them that put additional oil into the system but if you have it in the upright position then the oil won't go in. The manufacturer should know best!