API 5CT oil casing pipe hydrostatic pressure test

Hydrostatic pressure test is an indispensable link in the steel pipe production and manufacturing process. Its function is to detect the leakage resistance of the steel pipe under standard test pressure and pressure stabilization time. Like radiography, ultrasonic and other flaw detection processes, it is an important means to inspect the overall quality of steel pipes.

A popular description is a test in which the oil casing is filled with water and tested under pressure to maintain its ability to maintain a specified pressure without leakage or rupture. Its operation includes three steps: flushing, pressure testing, and water control.

API 5CT oil casing pipe hydrostatic pressure test:

1) Key technical operation points of the position

1. Parameter setting: Set the test pressure value, pressure stabilization time, etc. according to the specifications, steel grade, and thread type of the oil casing pipe to be tested;
2. Perform a full-length hydrostatic test on each pipe. The actual test pressure and minimum pressure stabilization time must comply with the regulations of the process card (sometimes the pressure stabilization time is appropriately adjusted according to the quality of the raw materials);
3. During the pressure test process, check whether each seal is intact and whether there is leakage at any time;
4. The test pressure control range of the pipe is: ≥ standard hydraulic test pressure;

5. Fill in the hydrostatic pressure test record carefully.

2) Precautions for position operation

1. If the actual hydrostatic test pressure cannot reach the standard pressure due to equipment reasons, the technical department must be notified in time to make corresponding process adjustments.
2. If the pressure stabilization effect is not good during the pressure test, check the seals and pipelines for leaks and repair them if necessary.
3. After the pressure test, pay attention to check whether the pipe body is damaged.

3) Relevant provisions of API-5CT standard on hydrostatic pressure test

1. The hydrostatic test pressure value of oil casing with couplings and threads is the lowest value of the hydrostatic test pressure of the flat-end pipe, the maximum hydrostatic test pressure of the coupling, and the internal pressure leakage resistance, but the standard maximum pressure is 69MPa. And the calculated pressure value is generally rounded to the nearest 0.5MPa.
2. According to API requirements, hydrostatic test pressure measuring devices should be calibrated within 4 months before each use.
3. If customers have special requirements, higher hydraulic test pressure can be selected.
4. Hydrostatic pressure test leakage is the basis for rejection.

5. Unless otherwise agreed between the purchaser and the manufacturer, hydrostatic testing is not required for coupling blanks, coupling materials, nearby materials or Q125 steel grade pup joints.

Go here to learn more about "What are the grades of OCTG casing?"