TAPI5CT oil casing is widely used.

1. There are three types of API rules: R-1 is 4.88 to 7.62 m, R-2 is 7.62 to 10.36 m, and R-3 is 10.36 m to longer.

2. Some foreign objects are marked with LTC, that is, the filament fastening sleeve.

3. The main importing countries of oil casing are Germany, Japan, Romania, Czech Republic, Italy, the United Kingdom, Austria, Switzerland, the United States, Argentina and Singapore. The import guidelines refer to the American Petroleum Institute regulations API5A, 5AX, 5AC. The steel grades are H40, J55, N 80, P110, C75, C95, etc. 

4. In addition to API guidelines for petroleum casing imported from Japan, there are also a few guidelines based on Japanese factories (such as Sumitomo, Kawasaki, etc.). The quantity of steel is nc-55e, nc-80e and nc-180.nc-80h.

5. In the claim case, there are some external defects, such as black buckle, damage to the wire buckle, pipe body folding, the difference between the distance between the break buckle and the thread, the poor J value of the coupling, etc. Internal quality issues.