ASTM B280-20 pdf free.Standard Specification for Seamless Copper Tube for Air Conditioning and Refrigeration Field Service. 1. 1 This specification establishes the requirements for seam- less copper tube intended for use in the connection, repairs, or alternations of air conditioning or refrigeration units in the field NoTE 1-Fittings used for soldered or brazed connections in air conditioning and refrigeration systems...