ok, when figuring the weight capacity of your recovery cylinder to know the maximum it will hold the books say it is stamped on the tank. Ok. I went to work and got our tank out and what is stamped is W.C. 47 and T.W. 23. Ok I asked the boss about this and he said T.W. stands for total weight. He didn't know what W.C. meant. Well I knew he was wrong. So I went to the manufacture web.site. Ok water capicity, and Tare weight. Then on to ARI website. Guideline K = Maximum allowable gross cylinder weight = 0.8 x WC x SG + TW. OK guys none of this was said when I read and took the certification book and test. Every thing I read in the manuals says 80% capicity. But hey you got to know how to do the math. But you also have to know the formula. What peeked my interest was after getting my certification in march 2004, it seems the AC guys I have worked with don't know this stuff but they have had certification for years. BE HONEST... how many techs do you think actually know about the formula? And did you?
THIS IS JUST AN OBSERVATION; I AM INTERESTED IN YOUR COMMENTS.