... :tubing couplings Std Ref:API 5CT Grade:J55,K55,N80,L80,C90,P110, N80-1,N80-Q ... to API SPEC 5CT AND 5BAPI couplings for oil tubing and casingSize and SpecificationsDescriptions and sizeType of ... -1/2"EUE141.30*158.756.051.Grade:J55, K55, N80-1, N80-Q, L80, C90, P110 ... couplings, stabilizers, air-liquid separators, anchors of oil pumps and revolving sand gravitated device, etc API 5CT oil pipe couplings