Name:tubing couplings Std Ref:API 5CT Grade:J55,K55,N80,L80,C90,P110, N80-1,N80-Q Type: NU, ... .894-1/2"EUE141.30*158.756.051.Grade:J55, K55, N80-1, N80-Q, L80, C90, P110 2.We also ... pup-joints, adapter couplings, stabilizers, air-liquid separators, anchors of oil pumps and revolving sand gravitated device, etc API 5CT oil pipe couplings