On Fri, 15 Apr 2011 09:58:42 -0400, "Wilbur Hubbard"
wrote:

Or, alternately, purge the system with dry nitrogen, then vacuum pump.

http://www.air-conditioner-selection...n-skilled.html

That web site sounds like it was written by a three year old ESL
(English as a Second Language) student. Some of the advice is OK but
a much better source is Nigel Calder's book:

http://www.amazon.com/Refrigeration-Pleasureboats-Installation-Maintenance-Repair/dp/0071579982