api 5000API 6A TEMPERATURE CLASS L: SERVICE -50ºF TO 180ºF (-46ºC TO 82ºC) 2,000 3,000 5,000 API 60K Alloy Steel Corrosive (CO2) & Sour (H 2S) NACE4 MR01-75 T26F F 2,000Api 6a Wn Flanges applications including pressure classes – 720 psi and 960 psi, the API specified no changes to the ASA B16.5 Standard, using the 300 lb. and 400 lb. flanges