What are the rules for the thread of the casing pipe?
Date:2018-06-21 View:551 Tag:What are the rules for the thread of the casing pipe?
Internationally, the requirements for casing threads between one pair of inner and outer cones meet the requirement of end face allowance only, and the axial displacement can be used to complete the interference of the connection surface. And it can be used to improve the processing quality of the connection area, increase the axial force to increase the pressure of touch area and touch area, and then get a more compact ring pressure touch area. The larger the touch area, the less likely the leakage path is, and the more reliable the sealing function is. Casing thread is a special conical seal with thread grooves and taper pipe threads.
When the conical tube thread meets, only the surface allowance is satisfied, and the preload in the seal surface can be easily obtained by tightening the thread and causing the axial displacement. After reviewing the conical sealing method, when the inner and outer cone threads match each other, a continuous and discontinuous ring pressure contact area must be formed to keep the seal on the connecting surface.
In the thread cone of the casing, the area of the conical helicoid is increased due to the existence of threads, resulting in labyrinth labyrinth, where the pressure medium is difficult to pass. This is good for sealing, but it also adds various touch errors on the thread touch surface, which increases the ability to leak. This requires that all elements of taper thread should be as accurate as possible during drawing and production. In the process of use, the tightening force is tightly twisted in a certain amount of interference during the use of its internal and external threads, so that the threaded teeth are kneaded, stretched, twisted and other messy and deformed, to make up for the shortcomings of the touch surface, to block the gap on the touch surface and to block the leakage path.