Also named Filling Valves,Refrigeration Charging Valves,Refrigeration Service Access Valves,Braze Refrigeration Air Conditioning,Service Access Valve, Refrigeration Charge Port,Air conditioning Copper Extension Tube access port,Needle Refrigerant Freon HVAC Check Charging Valves.refrigeration access valves and accessories for your commercial refrigeration and air conditioning systems,it is used to vacuum or charge refrigerant during maintenance of air conditioning system of R22, R407c or R410a. Made with top quality copper pipe, with brass needle, and welding T2 copper tube. Standing Pressure 3.5 MPA .It is widely used to charge various refrigeration and air conditioning refrigerant. It is a fine-tuning valve needle valve plug is mainly used to adjust the refrigeration flow. Trim valves require valve port open gradually increases from off to on the maximum continuous finely adjusted.