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  1. #1
    Join Date
    Aug 2004
    Location
    Texas
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    88
    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.

  2. #2
    Join Date
    Aug 2004
    Location
    Texas
    Posts
    88
    OH YEAH, a past thread from the 18th said that if you have a 30# cylinder and a tare weight 16.3 and the overall weight is 40 to stop..you have 24 #s in the tank and that is the limit. But WHOA,, 0.80 X 30 + 16.3 = 40.3#. 40.3 is the "real" maximum allowable gross cylinder weight. Guideline K section 6.3. Check it out. It looks like most techs are taking the W.C. x 80% to equal the max. allowable. in this case that would calculate 24, when they actually could put much more in safely.

    And what is this Specific gravity of the refrigerant recovered at 77 degrees?

  3. #3
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    68,308
    wood, reread what you posted the second time.

    40.3-16.3=24

    so 24# of r22 is all that, that cylinder can hold legally.

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  4. #4
    Join Date
    Aug 2004
    Location
    Texas
    Posts
    88
    beenthere
    W.C.x.8 plus T.W. = max. allowable..
    T.W. equals the weight of the container empty. Tare Weight. We don't care about the wieght of the cylinder itself. We are actually concerned about the wieght the cylinder can handle inside the drum. Think about it. Then look at the ARI website. They will comfirm this.

  5. #5
    Join Date
    Jan 2004
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    Lancaster PA
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    Gross maximum weight includes tare weight.

    Water capacity does not include tare weight.
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  6. #6
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  7. #7
    Join Date
    Aug 2004
    Location
    Texas
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    ok..I see the chart on page 16,, but above the chart it says according to ari.org. When you go there and use the formula they give it comes out different. What am I doing wrong?? Using their formula W.C. or 30 x .8 = 24 plus T.W. or 24 plus 16.3 = 40.3 The Ari.org guideline says this is the maximum allowable gross cylinder wieght. The .8 above is the 80% factored in.

    I want to believe you, but it doesn't make sense to me. I mean I am going to the source of the required code. Not the sells brochures. just take a look at it, guideline K.. I have printed it out and took it to work and let the other techs read it. They have now come to the same conclusion I have. Math is math....or is this a typo on their documents?

  8. #8
    Join Date
    Jun 2003
    Location
    Florida
    Posts
    9,548
    I believe you take 80% of the wc(37.6 lbs in this case) and add the tare weight to it (23 in this case). When removing refrigerant, you stop when the total weight on your scale is 60.6 lbs. The jug isn't full, but it allows for expansion when the freon is heated sitting in the back of your service vehicle. there really shouldn't be a formula for this, they should just state it on the cylinder to prevent overfilling, but i guess the formula makes someone feel important.
    If everything was always done "by the book"....the book would never change.

  9. #9
    Join Date
    Jan 2004
    Location
    Lancaster PA
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    68,308
    The recovery machine manufactures don't use the SG in their formula.

    So yes you can get another pound or 2 in, depending on the cyclinders wc.

    But, if your scale is off, then you are subject to large DOT fines.

    Also, the SG of 12, 22, 134a, 404a etc, etc ,etc, are different, so the same WC cyclinder holds different lbs, of different refrigerants.


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  10. #10
    Join Date
    Aug 2004
    Location
    Texas
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    thank you smokin68, this is what I come up with.. our tank says 47.7, tare wieght 23....in which case you take 47.7 x 80 % = 38.16 then ADD 23 and you get 61.16 pounds. This is the maximum allowable wieght for this particular cylinder when removing refrigerant. When you get to 61 pounds on your scale then stop. Time for an empty cylinder.

    thankyou thankyou!

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