Thread seal of
tubing & casing is a special thread oil industry, mainly used for oil pipeline connecting oil pipeline and various accessories and connections, a seal does not require any filler (such as flax, yarn, asbestos fiber, rubber, etc.) simply coated with a suitable thread sealant can achieve sealing conical threads. Inside, when combined with external thread mutually centering the guiding role of good, easy assembly, disassembly, can withstand large axial force, interchangeability, long life and can be reused many times. Because of these characteristics, in the oil industry, the amount of large, very versatile, especially its hydraulic seal reliability is more important role in the use.
1. Conical sealing
When a pair of inner and outer cone with each other, as long as the end face of the balance enough, you can achieve with a combination of axial displacement at the surface interference. And can improve the quality of the processing of the joint surface, increasing the axial force method of increasing the contact area and pressure at the contact surface, thereby obtaining a tighter annular pressure contact section. The greater the possibility of the formation of the contact area of the leakage channel is also smaller, more reliable sealing performance. Tapered pipe thread sealing - and oil pipeline thread is a special thread cone seal forms a groove with.
2. Thread sealing
As long as the end face of the balance (standoff) enough, you can tighten the thread and taper pipe thread connection generated when the axial displacement easily get a preload at the sealing surface. Through the discussion of the form of cone seal, when the inner and outer tapered pipe thread with each other at the junction surface must form a continuous, uninterrupted annular contact area in order to maintain the pressure seal. Thread cone on the oil pipeline, due to the presence of the thread increases the contact area of the tapered helical surface, resulting in a pressure medium through a difficult maze labyrinth. It is advantageous for the seal, but also make the thread contact surfaces of various contact error increases, which in turn increases the possibility of leakage. This requires that tapered pipe thread in the design, manufacture various geometric elements should be as accurate as possible. And when in the course of the tightening force is applied within it, an external thread tightly screwed to produce a certain amount of interference, so that thread by squeezing, stretching, bending and other produce complex deformation of the contact surface between the remedy defects, plugging gaps exist in the contact surface, cutting off the leakage channel.
