ReplyIf you can't read it the numbers are
WC= 239
TW= 79.5
Professional Member*
This sticker is on one of our big recovery tanks.
Correct me if I'm wrong but this should NOT weigh 300-320 total. See pics:
Professional Member*
If you can't read it the numbers are
WC= 239
TW= 79.5
Professional Member
Is this a trick question? Here's the formula for determining the gross weight of a recovery cylinder. .8 x WC x SG + TW = GW
WC = water capacity of cylinder in lbs.
SG = specific gravity of the refrigerant being recovered (@25*C)
TW = tare (empty) weight of the cylinder
So if you were recovering R-12 you would have .8 x 239 x 1.315 + 79.5 = 330.928 lbs.
R-22 would be .8 x 239 x 1.197 + 79.5 = 308.366
So I'd say, the tag is close to being correct. If you were recovering R-12 and you put as much as is allowable you'd be 10 lbs. over.
Professional Member*
My bad forgot to mention it's r-22. If I'm doing it right I get 282lbs and change Total Tank Weight.Originally Posted by KnewYork
239 W.C. x 1.06 (r-22 filling factor) = 253.34 (fill weight of r-22)
253.34 (fill weight) x .80 (80% for safe fill weight) = 202.672 (lbs of R-22 allowed in cylinder)
202.672 + 79.5 (TW of cylinder) =
282.172 LBS TOTAL WEIGHT OF CYLINDER
Professional Member
Not sure where you came up with an R-22 "filling factor" of 1.06. Paragraph 6.3.1 of the AHRI Guideline K-2009 states the formula exactly as I stated it below. The specific gravity of R-22 at 77* F is not 1.06, it's 1.197.
If you want to put less R-22 in the cylinder there's nothing wrong with that, but at 77*F you could put 33 more pounds of R-22 in that cylinder to obtain an 80% fill.
Professional Member*
What happens when the truck hits 130* in July?
The 1.06 comes from the density of R-22 at 130* / the density of water to get your "filling factor".
If I'm saying this wrong someone please step in and correct me.
Professional Member
If you are using the SG at 130*F then you are correct. At this time of year I think you'd be safe to use the SG at 77*F. The whole crux of your question comes down to what you use for SG. The AHRI Guideline also states "SG = Specific gravity of the refrigerant recovered at 77°F [25°C]". It doesn't say anything about how hot the truck will be when it is transporting the cylinders. If you are recovering the refrigerant at 77*F, then I would follow the AHRI guideline. The cylinder will be only 80% full and that is to allow for expansion due to heat.
If recovery is done at higher temperatures then an adjustment down would be necessary.
Now for my question. If you are recovering less refrigerant than what is stated on the tag, what's the problem?
Professional Member*
The tag is wrong, that's the problem.
The last big tank we had everyone was wondering why it stopped filling at 282lbs. I calculated what it should be and sure enough it came out to 282. Now I don't know this for sure but I'm almost positive it had a safety float. There must have been 3 different techs trying to fill that thing and it would not budge past 282.
For my safety and others I'm using 130* just for that what if. What if it sits in our shop till July then travels across the country inside some truck and the same thing goes for the 50lb tanks. Im not taking any chances that the tank is always going to be a cool 77*
Professional Member
That's why you only fill to 80% at room temp.
Posting Permissions