Hunan Steel Industrial Zone, No.9 Xiangfu Road, Yuhua District, Changsha, China
Casing coupling is a short pipe used for connecting two casing pipes which have threads. This pipe coupling has internal threads (box thread) machined to match the external threads (pin thread) of the long joints of casing. The two joints of casing pipe are screwed into opposite ends of the casing coupling. The couplings are normally made of the same grade of steel as the casing. Through their strength can be different from the casing. Tubing coupling is a type of drilling tool used in oil field. It is mainly used for connecting oil pipes. This pipe coupling has solved the problem that the existing couplings tend to crack due to stress concentration. The oil pipe ends and the inner wall of the steel coupling are connected through threads. The ends of the coupling and the oil pipe have the same type of threads. This type of connection is not easy to crack and the connection effect is good.