1. From the surface, that is, inspection by appearance. The appearance inspection of welded joints is a simple and widely used inspection method. It is an important part of finished product inspection. Its main purpose is to find defects on the weld surface and deviations in size. Inspection is usually carried out by naked eye observation, combined with tools such as standard templates, gauges, and magnifying glasses. If there are defects on the weld surface, there may also be problems inside the weld.

2. Physical method inspection: Physical inspection methods are ways of measuring or inspecting using certain physical phenomena. For the detection of internal defects in materials or workpieces, ultrasonic testing, radiographic testing, penetration testing, and magnetic testing are usually used.

3. Strength inspection of pressure vessels: For pressure vessels, in addition to the need for sealing tests, strength tests are also required. Common test methods include water pressure testing and air pressure testing. Both tests can detect the weld sealing of containers and pipelines operating under pressure conditions.

4. Compactness test. This method is mainly for welding containers for storing liquids or gases. If the weld has no penetrating cracks, pores, slag, impermeability, or loose structure, it can be used to find compaction tests. The specific test methods include: kerosene test, water test, etc.

5. Hydrostatic test. This test is mainly to see if there is any leakage during the hydrostatic test of the steel pipe (the test pressure is P = 2ST / D, where S is the hydrostatic test pressure in MPa, and the hydrostatic test pressure is 60% of the corresponding specified output, and the adjustment time: D <508 test pressure shall not be less than 5 seconds; D ≥ 508 test pressure shall not be less than 10 seconds).

6. Structural steel pipe welds. Non-destructive testing of steelhead welds and annular joints requires X-ray or ultrasonic testing. For some steel spiral welds for conveying flammable common fluids, 100% SX ray or ultrasonic testing is required in time. 

1. Check the surface of the spiral steel pipe to see whether the production process of the spiral steel pipe is exquisite. Generally, it is necessary to study and analyze the spiral steel. The cross-section of the fake and inferior spiral steel pipe is elliptical. The reason is that the manufacturer saves raw materials, and the pressure of the first two rollers of the finished product is slightly larger. The compressive strength of this spiral steel pipe is greatly reduced, and it does not meet the specifications and dimensions of the screw steel products.
High-quality spiral steel pipes have symmetrical components, high cold shear tonnage, and smooth and neat inner holes of the cutting head. However, due to the poor quality of these materials, cutting head holes are often used, which will lead to uneven bumps and no metal texture.
2. Knock on the spiral steel pipe and listen to the sound after knocking. Suppose the sound is crisp and the echo is not chaotic. In that case, it means that this spiral steel pipe is made of new material technology, rather than the comprehensive development and utilization of abandoned spiral steel pipes.
3. The shape detection of the butt weld of spiral steel pipes is a detection mode with simple detection technology and universal application ability. It is an important content of finished product quality inspection. The key is to find out the defects and specification errors on the welding surface of spiral steel pipes. Generally, it is tested based on human visual inspection, relying on special tools such as specification models, instruments, and high-magnifying glasses. If there are defects on the weld surface, there will also be defects inside the weld.

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