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How do you determine the safe liquid level in your recovery cylinders? I have been talking to techs over the years and I always get different answers. I know the correct way is to calculate with a bunch of formulas from water cap. and ratios of saturated temps of liquid. I am talking real world. For example.. If you are using a 125# cylinder, I have been told to fill to net weight from 100# or 125#.

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70% of container capacity

125 x .7 = 87.5

What refergerant is it?

if you have a bottle to hold 30 pound r-12 , how many pounds of r-22 will it safely hold?

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Why are you using 70%? Is that just a safe percentage for all refrigerants? I typically use 80%. I use alot of different refrigerants. 22,12,502,123,11, ect..

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What most people forget is the capacity of the cyclinder is at 70F. If you fill it 80% and it sits in your truck on a 95F day it could go hydrostatic. Look at your pt chart for the most reasonable temp the cyclinder will see but in my opion 80% is pushing the limits, if it will see unusually high temps.

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For example 125# recovery cylinder at ambient density of R22 at 130* is 66.312.
Take that factor 66.312 divided by water density 62.4 = 1.06. If the WC of a 125 is 121, mutiply 121 and 1.06= 128.26.
The tank has a total liquid capacity of r22 of 128.26 @ 130*. 80% is 102.6 net refrigerant.

Quick method is 125 tank multiplied by .8 =100 net refrigerant

6. 80%

formula is

water content x filling ratio + tare weight

7. I usually fill them to where I feel comfortable carrying them....rest goes into that big recovery cylinder in the sky.....

8. I guess I never much thought about that. Every time I exchange or purchase a new recovery bottle, I weigh it empty and write it on the cylinder. Regardless of which refrigerant I am recovering, when I get to, or close to the rated weight, I stop adding to that tank. I think the 30 pounders weigh around 16 pounds empty. I would only fill that tank to about 45 pounds or so. I know about the rule of 80%, but isnt that already built into the volume of the tank? Interesting.

9. ## Recovery Cylinders

Each and EVERY bottle is stamped with capacity in WC.
The Simple fact of LAW states 80% of WC.

You can go less, but not more.

There is actually no such thing as a 30, 50, or 125 lb.
recovery cylinder.

The capacity of any recovery cylinder is stamped and
Approved only for what it was certified at.

This is not a place for Rule of Thumb.

If DOT, or any other Department of Regulation
checks you out, you had better be legal, or they
will write you a little Rule of Thumb ticket that

Regards.........

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## Re: Recovery Cylinders

[QUOTE]Originally posted by gonefishing
[B]
Each and EVERY bottle is stamped with capacity in WC.
The Simple fact of LAW states 80% of WC.

You can go less, but not more.

There is actually no such thing as a 30, 50, or 125 lb.
recovery cylinder.

The capacity of any recovery cylinder is stamped and
Approved only for what it was certified at.

This is not a place for Rule of Thumb.

If DOT, or any other Department of Regulation
checks you out, you had better be legal, or they
will write you a little Rule of Thumb ticket that

================================================== ======
You are still cutting short the capacity of you cylinder if you are not converting your WC to the correct refrigeration density.
If a 125 recovery tank has a WC of 121, you could fill to a net of 102.6 of R22 using the density factor of 1.06.
If you just use WC of 121 @ 80% will be 94 pounds.

[Edited by ej45 on 02-18-2006 at 09:42 PM]

11. EPA regulations state that you are not to fill any cylinder above 80% of its rated capacity.

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Originally posted by ej45
For example 125# recovery cylinder at ambient density of R22 at 130* is 66.312.
Take that factor 66.312 divided by water density 62.4 = 1.06. If the WC of a 125 is 121, mutiply 121 and 1.06= 128.26.
The tank has a total liquid capacity of r22 of 128.26 @ 130*. 80% is 102.6 net refrigerant.

Quick method is 125 tank multiplied by .8 =100 net refrigerant
I'm with the others on this, while your research into refrigerant densities at given P/T's is arguable, the rule of the law is 80% W.C. It could very well have something to do with air and non-condensibles, or excess oil from the system, but you cannot go over the afore mentioned amount.

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Originally posted by hvac3901
Originally posted by ej45
For example 125# recovery cylinder at ambient density of R22 at 130* is 66.312.
Take that factor 66.312 divided by water density 62.4 = 1.06. If the WC of a 125 is 121, mutiply 121 and 1.06= 128.26.
The tank has a total liquid capacity of r22 of 128.26 @ 130*. 80% is 102.6 net refrigerant.

Quick method is 125 tank multiplied by .8 =100 net refrigerant
I'm with the others on this, while your research into refrigerant densities at given P/T's is arguable, the rule of the law is 80% W.C. It could very well have something to do with air and non-condensibles, or excess oil from the system, but you cannot go over the afore mentioned amount.

I am still filling to 80%. Refrigerant has a different density than water. I am using the method from ACCA manual.

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