Coarse Thread Safety Joint allows quick release from drilling, fishing, testing, washover, or tubing strings when they become stuck, leaving a minimum of pipe in the hole, thereby reducing the problems of fishing or sidetracking. The new design is simple, eliminating the need of a release ring mechanism and lengthy disengagement procedures.Safety Joints are available in a full range of types, sizes,and lengths.
Coarse Thread Safety Joints are a simple, two-piece, four-seal design that permits easy disassembly for cleaning and lubrication. These Safety Joints consist of an upper pin section, a lower box section and four seals. The upper pin section has a box connection up for connecting to the tool joint and a male coarse thread down for connection to the box section. The pin section is grooved at the top and bottom to accommodate the O-ring type seals above and below the threads to seal the Safety Joint from both inter-seals are rated for high pressure operation and are capable of with standing up to 10,000 psi in
continuous service. The seals are rated for all normal pump pressures in continuous service.
The box section has a female coarse thread matching the male thread of the pin section and has a tool joint pin connection down for connectingto the pipe.
The coarse thread design of the pin and box sections allows speed and ease of engagement. When the Safety Joint is made up tightly, the joining coarse threads grip each other securely, pulling the surfaces into complete contact and transform the Safety Joint into a rigid unit. Once in the string the Safety Joint is resistant to vibration, heavy loads and left- or right-hand torque. The coarse thread design will not permit the safety Joint to loosen or wedge during operation. The Safety Joint's design allows the transmission of torque in the left or right-hand direction.
The Safety Joint will disengage with simple left-hand rotation between 20%~40% of the tool’s right-hand make-uptorque.