hello everyone
i need some advise or referencing on a few things.

1. i have client who is buying r-22 disposables from us (we are in the middle east so still work with disposables) and filling window units. they are just filling the units with vapor and after filling 3 units the cylinder freezes.
these are standard units they are filling, they are not anything special which requires huge amounts of gas.
should they be filling direct with vapor? or liquid? or liquid then vapor? and is there any documentation to support this?
also should the cylinder be freezing up like this after only filling 3 window units?

2. is there any document showing how to fill a large unit say charging a unit with between 20-100kg ? what i am looking for is mainly something that says you should not charge a large unit by vapor and rather liquid as its quicker and easier? has anyone got any kind of reference doc?


any help on either one of my problems would be greatly appreciated.

thanks
Phill