The hydrostatic pressure test of oil casing pipe is an indispensable part of the steel pipe manufacturing process. Its function is to detect the leakage resistance of the steel pipe under the standard test pressure and the voltage stabilization time. Like radiographic, ultrasonic and other flaw detection techniques, it is an important means to inspect the overall quality of steel pipes.
a) Key points of post technical operation
1. Parameter setting: Set the test pressure value and voltage stabilization time according to the specifications, steel grade, and thread type of the pipe to be tested;
2. Perform a full-length hydrostatic pressure test on each pipe. The actual test pressure and minimum voltage stabilization time must comply with the regulations of the process card (sometimes the voltage stabilization time is adjusted appropriately according to the quality of raw materials);
3. During the pressure test, check whether the seals are intact and leaking at any time;
4. Pipe test The pressure control range is: ≥standard water pressure test pressure;
b) Precautions for post operation
1. If the actual hydrostatic test pressure cannot reach the standard pressure due to equipment reasons, the technical department shall be notified in time to make corresponding process adjustments.
2. If the voltage stabilization effect is not good during the pressure test, check whether the seals and pipelines are leaking, and repair if necessary.
3. After the pressure test, pay attention to check whether the tube body has any knocks.
c) API-5CT standard for hydrostatic pressure test related regulations
1. The hydrostatic test pressure value of the pipe with coupling and thread 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 The value is generally rounded to the nearest 0.5MPa.
2. According to API requirements, the hydrostatic test pressure measuring device should be calibrated within 4 months before each use.
3. If the customer has special requirements, a higher hydraulic test pressure can be selected.
4. Leakage in hydrostatic pressure test is the basis for rejection.
5. Unless otherwise agreed between the purchaser and the manufacturer, the coupling blank, coupling material, nearby materials or Q125 steel grade sub-joints are not required to undergo hydrostatic pressure test.