... 5CT Near Tianjin Port,fast delivery China famous brand 1.API 5CT seamless tubing coupling and casing coupling2.ISO ... .756.05 J55,K55,N80Q,N801,L80,P110Casing Coupling4-1/2"STC127.00*158.755.23J55,K55,N80Q,N801 ... ,K55,N80Q,N801,L80,P1107"STC194.46*184.158.39 J55,K55,N80Q,N801,L80,P1107"LTC194.46*228 ... are welcome to negotiate business with us!! Jinggong API 5 CT 3-1/2 EU J55 S13 coupling with sealing ring