It can be used for vacuuming, because when the tank is first received, it is filled with air, and the tube needs to be vacuumed to recover the refrigerant.
By vevor
It is used to bleed off small amounts of refrigerant gas contaminated with air. By comparing the vapor pressure and temperature of the refrigerant to a published table, the purity of the refrigerant can be determined.
By Rich
This is a valve used for testing.
By vevor
