Abstract: Provided is a coupling system comprises a first tubular member with a top end and a second tubular member with a bottom end, defining together a longitudinal axis. One of the top end of the first tubular member and the bottom end of the second tubular member is configured with a longitudinal axially extending socket portion. The other one of the top end of the first tubular member and the bottom end of the second tubular member is configured with a longitudinal axially extending plug portion for coaxial snug receipt within the socket portion. Each tubular socket portion and the plug portion is configured with a lock opening intersecting the longitudinal axis. The coupling system includes a locking plug configured for locking engagement of the lock openings while in register with one another, thereby preventing axial or rotary displacement of the first tubular member and the second tubular member.