Detailed Explanation Of The Inspection Process Of Lined Pipes

With the upgrading of industrial infrastructure and the improvement of environmental protection requirements, lined pipes are widely used in chemical, energy, water supply and other fields due to their advantages such as corrosion resistance and extended service life. However, the quality of lined pipes directly affects their performance and safety, so a scientific inspection process is essential. This article will introduce the inspection process of lined pipes in detail to help related companies better control product quality.

1. Appearance inspection

Appearance inspection is the first step in the inspection of lined pipes, mainly checking whether there are defects such as cracks, bubbles, scratches, etc. on the surface of the pipe. Inspectors usually use visual inspection or low-power magnifying glasses to assist in observation to ensure that the inner and outer surfaces of the pipe are smooth and without obvious physical damage. Although this link is simple, it can effectively exclude obviously unqualified products and lay the foundation for subsequent inspections.

2. Dimension measurement

Dimension measurement is a key step to ensure that the lined pipe meets the design requirements. The inspection content includes parameters such as the inner diameter, outer diameter, wall thickness and length of the pipe. Usually, tools such as vernier calipers and ultrasonic thickness gauges are used for precise measurement to ensure that the pipe size is within the allowable tolerance range. If the size deviation is too large, it may cause installation difficulties or affect the performance, so this link must be strictly controlled.

3. Nondestructive testing

Nondestructive testing is the core link of the quality assessment of lined pipes, mainly including ultrasonic testing, radiographic testing and magnetic particle testing. Ultrasonic testing is used to find cracks or pores inside the pipe; radiographic testing can clearly show the distribution of defects inside the pipe; magnetic particle testing is suitable for detecting surface or near-surface cracks. These methods can comprehensively evaluate its internal quality without destroying the pipe to ensure the reliability and safety of the pipe.

4. Pressure test

Pressure test is used to verify the pressure resistance of the lined pipe. Usually, water pressure or air pressure test is used to pressurize the inside of the pipe to 1.5 times the design pressure and keep it for a certain period of time to observe whether there is leakage or deformation. This link can effectively exclude pipes with substandard pressure resistance and ensure their safety in actual use.

5. Chemical performance test

For lined pipes for special purposes, chemical performance tests are also required, such as corrosion resistance test and high temperature resistance test. By simulating the actual use environment, the long-term stability of the pipeline is evaluated to ensure that it meets the needs of specific industries.

The inspection process of lined pipes covers a full range of evaluations from appearance to performance. Only by strictly following the inspection standards can product quality be ensured and reliable protection can be provided for industrial applications.