How to inspect the welding quality of straight seam submerged arc welded steel pipes

Number of visits：58 seconds Update time：2025-12-22

Directly buried arc welded steel pipes (ERW) are widely used in oil, natural gas, industrial heating and municipal pipeline networks. The quality of welding is directly related to the safety and service life of pipelines. Therefore, buyers and engineers must strictly inspect the weld seams during procurement and construction.

I. The importance of welding quality acceptance

Ensuring safe operation: Weld defects may lead to leakage, pipe burst or accelerated corrosion.

Compliance with standard requirements: Different standards (API 5L, ASTM, EN, GB) all have clear requirements for weld seams.

Extended service life: High-quality welds ensure the long-term stable operation of pipelines and reduce maintenance costs.

II. Points for controlling the quantity of direct embedding steel pipes

(1) Restriction on fireworks

The adhesion method (double-sided embedding, double-sided molding) is approved.

Fire current, power, fire speed, fire quality and material quality.

The remaining height, the degree of expansion, and the quantity of expansion.

(2) Fireworks equipment

Whether or not the fireworks are compatible with the fireworks connection book (API/ASME/EN/GB equipment).

Please confirm whether or not the contact person has passed the test (WPS/PQR).

(3) Quality test record

Ultrasound wave (UT), radiation line (RT), magnetic powder (MT), 渗transit检测 (PT) yes or no proportional lottery.

Every article is written or written, and it can be traced back.

Joint request for approval or disapproval of quality report.

(4) Environmental construction conditions

Whether or not to operate under suitable temperature and humidity conditions, avoid low temperature explosion.

Wind and rain protection measures are required at the construction site.

(5) Post-period defense

Whether or not to move forward, to leave, to leave.

Should the outer embalming layer be covered or not, it should be placed in the burnt position to prevent rotting.

Whether or not to go on a long journey, try the food.

(6) Always see the connection table

Measures to prevent additional causes such as holes, holes, unburned holes, fissures, bites, and lumps.

III. According to the quality of the purchase

IV. Current delivery process

(1) Preparation work

I wrote a review about whether or not it was written, and recorded the production review.

Prepared tools: ultrasonic wave detector, player card measure, fire detector, radio mirror, gauge thickness.

(2) External tour

The surface of the flame is smooth, the surface is smooth, the surface is smooth, the surface is smooth, and the surface is transparent.

There is no concavity or convexity in the mouth.

Whether or not the scorching layer or the preservative layer is complete.

(3) Dimensional and geometric inspection

Measure the width and height difference of the weld seam to ensure they meet the requirements of the design drawings.

Check whether the straightness of the pipeline and the direction of the welds are uniform.

(4) Non-destructive Testing (NDT

Ultrasonic testing (UT) : To inspect internal defects in welds, such as cracks, incomplete penetration, and slag inclusions.

Radiographic testing (RT/X-ray) : Applicable to high-pressure pipes or API/EN standard requirements.

Magnetic particle testing (MT) or penetrant testing (PT) : They can be used for surface crack detection.

(5) Mechanical property verification

Tensile tests, bending tests and impact tests are conducted to ensure that the strength of the weld seam is consistent with that of the base metal.

For low-temperature environment projects, check the low-temperature impact performance of the weld seams.

(6) Records and Visas

Fill in the inspection results, defect records and re-inspection results in the weld acceptance record form.

The on-site acceptance personnel sign to confirm and file the information for future reference.

V. Always see the continuation and change