# Charging Cylinders



## DuMass (Jul 7, 2009)

Does anyone occasionally use these for small critical charge systems like PTACs, ice machines, window units, coolers, etc…?
I have two of the heated Dial-a-Charge models made by Robinair. One is calibrated for R12/22/502 and the other for R134A only. I think I overdid it a bit though by getting the 5 LB size… I probably would have been fine with the 2.5 LB models.


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## mechanicalDvr (Jun 25, 2009)

Haven't been anywhere near one of those puppies since working for my Uncle years ago. I just use the digital scale.


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## jvegas (Jun 17, 2009)

Never used one just a digital scale


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## mo-flo (Jun 17, 2009)

i've got an old one that i picked up at an auction years ago,never have used it......


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## pipefitter636 (Jul 17, 2009)

Haven't used one since the 80's. But on small systems you can't beat em, more accurate than a digital.


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## mechanicalDvr (Jun 25, 2009)

pipefitter636 said:


> Haven't used one since the 80's. But on small systems you can't beat em, more accurate than a digital.


 
How small are you talking? I use the scale for 18oz-23oz in Climatemaster untis all the time with great results.


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## beenthere (May 30, 2009)

Haven't used one of them since the 80's.

A good digital is easier to use. No temp compensation to consider.


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## hvaclover (May 15, 2009)

Got the same one you got, Dumass. Still use it today.


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## pipefitter636 (Jul 17, 2009)

beenthere said:


> Haven't used one of them since the 80's.
> 
> A good digital is easier to use. No temp compensation to consider.


 On a cap tube system less than 2lbs...... Don't think I would trust it...... jmo


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## beenthere (May 30, 2009)

To each his own.

Do reach ins, etc, that take less then 2 pounds, no trouble.

A calabrated digital scale is just as accurate as a charging cyclinder.
And no temp compensation errors.


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## pipefitter636 (Jul 17, 2009)

beenthere said:


> To each his own.
> 
> Do reach ins, etc, that take less then 2 pounds, no trouble.
> 
> ...


Glad I don't do the small sh*t any more....And your right(To each his own.)


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## DuMass (Jul 7, 2009)

beenthere said:


> To each his own.
> 
> Do reach ins, etc, that take less then 2 pounds, no trouble.
> 
> ...


Temperature compensation? Whooh… you have to turn the outer shield to match the reading of pressure gauge on top… not too hard to accomplish.
That's why it's called the Dial-a-charge.


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## beenthere (May 30, 2009)

Wait until you use it on a system, thatgives you a little trouble getting all of the charge in, when its not running.


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## DuMass (Jul 7, 2009)

That’s why there heated. You just plug them in to a 120V receptacle. This has the same effect as using a tank heater on a 30lb or 50lb cylinder.


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## hvaclover (May 15, 2009)

DuMass said:


> That’s why there heated. You just plug them in to a 120V receptacle. This has the same effect as using a tank heater on a 30lb or 50lb cylinder.


Unless it says Testo on it Beenthere gets a little confused.


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## beenthere (May 30, 2009)

hvaclover said:


> Unless it says Testo on it Beenthere gets a little confused.


LOL... I understand the word Bacarach too.


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## beenthere (May 30, 2009)

DuMass said:


> That’s why there heated. You just plug them in to a 120V receptacle. This has the same effect as using a tank heater on a 30lb or 50lb cylinder.


Come back and tell me how mch you like using one, in another 2 years.

I used a 5, and a 10 pound one.

Used them in both summer, and winter.

A digital scale is better, easier, and faster.


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## DuMass (Jul 7, 2009)

Okay, but I’ve already had them both for probably six or seven years now. I also own and use a digital scale as well as a digital programmable scale/refrigerant meter, so I use them all. 
I’m not trying to convert anyone here… just asked if anyone else used them occasionally for small critical charge systems.

They do have their advantages though. You can fill them in the shop or in the truck and bring them pre-filled to the equipment, so you don’t need to carry a digital scale and 30lb cylinder, just the charging cylinder. 
You would probably already have your extension cord running your vac pump at the equipment if needed for the heater.


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## beenthere (May 30, 2009)

I got tired of filling them. Thats time that can be spent doing other things.

Back when I used them. They didin't have digital scales yet(atleast not portable ones).

I did however, discover that they can be a great training aid, when you want to teach someone about saturation_p/t.



PS: When you want to put 4 pounds in the 5 pound cyclinder, and at 3.2 pounds its pressure is equal to the tank your filling from. You are using a recovery machine to remove the vapor to get the rest of the liquid refrigerant in, right?


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## pipefitter636 (Jul 17, 2009)

beenthere said:


> I got tired of filling them. Thats time that can be spent doing other things.
> 
> What...... like watching the micron guage, or smoking a cig.
> I did however, discover that they can be a great training aid, when you want to teach someone about saturation_p/t.
> ...


 Isn't that what you are supposed to do:laughing:


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## beenthere (May 30, 2009)

pipefitter636 said:


> Isn't that what you are supposed to do:laughing:
> 
> Yes it is. Seems like a pain to set up your recovery stuff, just to put gas in a charging cyclinder.





> What...... like watching the micron guage, or smoking a cig.


Generally. I let all wiring and other clean up till I'm pulling a vacuum.
Plus start writting up the invoice while the pump is running.


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## DuMass (Jul 7, 2009)

beenthere said:


> I got tired of filling them. Thats time that can be spent doing other things.
> 
> Back when I used them. They didin't have digital scales yet(atleast not portable ones).
> 
> ...


Believe me when I say I'm not advocating their use on a daily basis unless your partial to them and set up for it, but I can't simply dismiss them as antiquated technology either, as they are still a valid precision charging method with 1/4 oz accuracy. On the same note though, IMO, anyone that thinks their charging in the field to 1/10oz accuracy with a digital scale or refrigerant meter is fooling themselves, no matter what the scale/meter manufacturer says. 

The 5lb models that I have are overkill for what I use them for. The last time I used one of mine was back in June with a total charge of 12.5 oz of R22. I would never even get close to 3 or 4 lbs using one of these. You can use the recover pump or the tank method, which I believe is also outlined in the manual.
I've heard that you could also use an empty evacuated recovery cylinder in a 5 gallon bucket of ice water, depending on how much vapor you really need to bleed off. Haven't tried that one yet, but it sounds feasable.
As long as you use a new clean evacuated recovery cylinder, this collected vapor is still virgin refrigerant and can be used in another system, so it’s not wasted.


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## hvaclover (May 15, 2009)

i fixed a leak the other day and dialed in5.25 lb (I used the the extra volume that allows for expansion. So sue me). That was the base charge. Than i added liquid from my jug of 22 still i got the SC and SH.

2 1/2 ton split on a 1000 sq ft mobile home. 13 SEER. 

I like my Dailer cause I don't have to move a lot of crap to get to my scale.

Gotta connect extra hoses, run a cord...Dail a charge is just easier.


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## andreeakamaras (May 19, 2016)

no


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