Features of outer thick tubing
1. Enhance connection strength through upsetting of joints;
2. Sealing is achieved through cooperation with thread grease.
Disadvantages of the outer thick tubing:
1. Low processing efficiency, serious waste of factory capacity;
2. Slip failure easily occurs under tensile load;
3. Can't meet the requirements of gas seal under higher pressure;
4. The performance of the upper shackle is not good and the anti-sticking ability is poor;
5. Limited thread repair;
6. Difficulty processing accessories such as short sections;
7. The tubing order cycle is long, the price remains high.