1. Before connecting the valve to the refrigerant tank, turn its handle completely counterclockwise.
2. Set the disc to its highest position by turning counterclockwise.
3. Connect the central hose to the valve fitting.
4. Turn the valve handle clockwise to punch a hole in the sealed top.
5. Loosen the nut securing the central hose to the central fitting of the control pressure gauges.
6. Release the air for a few seconds, then tighten the nut.