50lb recovery tank charging

[Emdoller]

I have a 50lb recovery tank that’s hooked up to a robinair recovery machine.

If I disconnect the tank and want to charge my car using a scale instead of the machine, do I use the blue or red valve? I’m pretty sure it’s the blue but want to make sure.

Thanks,
Ed

[DetroitAC]

Red = Liquid is connected to a dip tube that goes to the bottom of the tank. You charge by weight pushing liquid from the red valve.

[Emdoller]

Thanks. So if I want to charge using vapor (car running through low side port) I can use blue valve but can’t trust the weight?

Thanks for your help!

Ed

[DetroitAC]

You can charge as a vapor with the compressor running. You can trust the weight this way as well. Automotive systems are so small it's easy to get the entire charge in as a liquid if you make the tank warmer than the car.

You will run into problems if you try to charge from the vapor valve without the car running. Liquid boiling off to replace vapor you extract will cool down the liquid and flow will stop.

[Emdoller]

Thank you. I’ll use the blue line with compressor running in the car and use the scale to track the Freon weight. I’ll also make sure I keep an eye on the gauges.

Thanks again!

[Emdoller]

Worked great, thanks again!