Shenzhen Shenzhen drilling wells drilling company in Shenzhen, Shenzhen kelly kelly wells located in the top of the drill string, there are two kinds of hexagonal and square. When drilling kelly bushing and Fang, fill the heart with the turntable, the turntable ground torque to drill to drive the rotation of the drill. Kelly standard full-length 12. 19 m, part of a long drive 11. 25 m. In order to meet the needs of the drill string together, Kelly also has a variety of sizes and connector types. Common side rod specifications in Table 2-19. Kelly wall thickness generally about three times larger than the drill pipe, and high-strength alloy steel, it has a greater tensile strength and torsional strength to withstand the entire weight of the drill string and drill and rotary drill string required torque. When kelly rotation, above the upper end of the disk is always in turn, the lower the disk in turn below. Kelly upper end to the threaded joints taps are left-handed threaded (Flip) to prevent rotation of the kelly shackle. Kelly to drill the lower threaded connections are all right rotation button (positive deduction), Kelly led the drillstring rotation, threaded on more and more tightly. In order to alleviate the lower kelly threaded joints (often disassembled parts) wear, often at the site to install a protective connector. http://www.syzjgc.com/ Drilling Engineering Co., Ltd. Shenzhen-source