Four-Knob Refrigerant
Manifolds (Gages) And A Vacuum
With all the renewed concern about keeping moisture and air out of air conditioning and refrigeration systems, there is very little printed information to show how proper evacuation should be performed. So, here is a brief description that you can pass on to your customers that are interested.
Evacuation is best done with a 4-knob, 4-hose manifold (gage set): Red (high side), Blue (suction side), Yellow (to refrigerant drum), and Oversize metal jacket (to vacuum pump).