 In order to clearly distinguish the steel grade, tubing, casing and its coupling should be painted with color codes respectively.Color bands should be painted on tubing and casing body longer than 600mm to either end.The whole outer-body of the coupling needs to be painted color and then color codes

API 5B and 5CT provide various steel grades and color codes of each grade, offering detailed and overall information of casing and tubing, which help you clearly pick out the most suitable products for different well application.