tips on charging very small systems

[gbfromsd]

I did a repair on a 134a reachin couple weeks ago.
Dataplate charge was miniscule, like 11 ozs. It's not
often I work on really small units so like a dummy I inverted the bottle and filled my hoses and manifold.
There went 11 ozs. It was then I wondered just how am
I gonna get exactly 11ozs into the system without wasting that much or more.

What's a good way to do this?

[crisrs]

I have used charging cylinders to charge 4-6 oz in small systems. My old cylinders were calibrated for r12 and 22 so I had to recalibrate them for 134 and other gases using a digital scale.

[frozensolid]

I would like to see your manifold. If it holds 11 ounces you must have 20 foot hoses on that thing.

[icemeister]

Since you are working with R134A you can vapor charge the system and the amount of refrigerant left in the hoses is negligible even on small systems like this.

Dial-a-Charge? I haven't seen one of those in twenty years! I've been using an electronic flat scale that's good to .5 oz and after nearly 15 years it still works well (unless I get it wet)

For liquid charging small systems, just get your charging hose up to tank pressure with the tank upright, invert the tank and zero out your scale. When you get to the required weight, close off at the tank.

[R12rules]

Originally posted by icemeister
Since you are working with R134A you can vapor charge the system and the amount of refrigerant left in the hoses is negligible even on small systems like this.

For liquid charging small systems, just get your charging hose up to tank pressure with the tank upright, invert the tank and zero out your scale. When you get to the required weight, close off at the tank.

Go with what he jus said.