Technical Point of Operation of Casing Pipe Workers

Basic requirements for hydraulic testing of casing pipe

The hydraulic test of casing pipe is an indispensable part of the production process of steel pipe. Its function is to test the leakage resistance of steel pipe under standard test pressure and voltage regulation time. Like the ray, ultrasonic, and other flaw detection processes, it is an important means to test the overall quality of petroleum steel pipes. The simple explanation is that the tube is filled with water and tested under pressure to maintain the specified pressure without leakage or rupture. Its operation includes three steps of rinsing, pressure testing and water control.

Technical points of operation of workers:

1. Parameter setting: according to the size of the oil pipe to be tested, the steel grade (simply the material of the oil casing), the thread type (button type) to set the test pressure value, and the voltage regulation time;
2. Perform a full-length hydrostatic test on each petroleum pipe. The actual test pressure and minimum voltage regulation time must comply with the requirements of the process card (sometimes according to the quality of the raw materials, the adjustment time is properly adjusted);
3. In the process of pressure test, it is necessary to check whether the seals are intact, leaking or not, and no water leakage traces;
4. Test of petroleum pipe The pressure control range is: ≥ standard hydraulic test pressure;
5. Carefully fill in the hydrostatic pressure test record;

API-5CT standard for hydraulic pressure test
1. The hydrostatic test pressure value of the coupling and threaded pipe is the lowest value of the hydrostatic test pressure of the flat end pipe, the large hydrostatic pressure test pressure of the coupling, and the internal pressure leakage resistance, but the standard maximum pressure is 69 MPa, and the calculation pressure The value is generally rounded to a close of 0.5 MPa.
2. According to the API requirements, the hydrostatic pressure test pressure measuring device should be calibrated within 4 months before each use.
3. If the demander has special requirements, a higher hydraulic test pressure can be used.
4. Hydrostatic pressure test leakage is the basis for rejection.
5. Except as otherwise agreed between the purchaser and the manufacturer, the coupling blank, coupling material, nearby materials or Q125 steel grade short sections are not required to perform hydrostatic test.
6. If the actual hydrostatic pressure test pressure cannot reach the standard pressure due to equipment reasons, the technical department should be notified in time to carry out the corresponding process adjustment.

In 2019, the key development tasks of the oil casing industry have been transformed into stable leverage and gradually de-leverage, structural adjustment, transformation and upgrading, mergers and acquisitions and high-quality development. Under the assistance of the relevant oil pipe seamless steel pipe industry integration fund and the implementation of regional integration plans, the leaders of the oil special pipe industry will further enhance the ability to integrate high-quality production capacity, accelerate the merger and reorganization, build a large enterprise production capacity echelon, and upgrade Industrial concentration promotes the high-quality development of the 
petroleum steel pipe seamless steel pipe industry. Generally speaking, for industries with sufficient supply, the increase of industrial concentration will increase the ability of large enterprises to dominate the market, and the degree of competition among enterprises will tend to decline, which will have a certain stabilizing effect on the oil casing seamless steel pipe market.