Basic requirements for hydraulic test of API 5CT oil casing

　Hydraulic test of API 5CT oil casing is an indispensable part of steel pipe manufacturing process. Its function is to test the leak resistance of steel pipe under standard test pressure and voltage stabilization time. Like X-ray, ultrasonic and other flaw detection technology, API 5CT oil casing is an important means to test the overall quality of API 5CT P110 Steel Oil Casing Pipe. The simple explanation is to fill the pipe with water and test its ability to maintain the prescribed pressure without leakage or rupture under confined condition. Its operation includes three steps: flushing, pressure testing and water control.

　　1. The hydrostatic test pressure of API 5CT oil casing is the low hydrostatic test pressure of flat end pipes, the high hydrostatic test pressure of coupling and the leakage resistance of internal pressure, but the standard high pressure is 69MPa, and the calculated pressure is generally rounded to close to 0.5 MPa.

　　2. According to API requirements, the hydrostatic test pressure measuring device should be calibrated within 4 months before each use.

　　3. If the demander has special requirements, higher hydraulic test pressure can be selected.

　　4. The leakage of hydrostatic test is the basis of rejection.

　　5. Unless otherwise agreed by the purchaser and the manufacturer, no hydrostatic test is required for the blank of API 5CT oil casing, the material of the coupling, the nearby material or the Q125 steel grade short joint.

　　6. If the actual hydrostatic test pressure can not meet the standard pressure due to equipment reasons, the technical departments should be informed in time to make corresponding process adjustment.