How to determine whether the wall thickness of the stainless steel pipe meets the requirements

To determine whether the wall thickness of the stainless steel pipe meets the requirements, one can use methods such as direct measurement, visual inspection, and professional testing. Here is a detailed introduction: 

1. Direct Measurement

1. Using Calipers: Calipers are a commonly used measuring tool that can be used to measure the outer and inner diameters of stainless steel pipes. By subtracting the inner diameter from the outer diameter and then dividing the result by 2, the wall thickness of the pipe can be obtained. During the measurement process, multiple measurements should be conducted at different parts of the pipe, such as the ends and the middle of the pipe. At each position, multiple points can be selected on the circular circumference for measurement to ensure the accuracy of the measurement results and avoid measurement errors caused by factors such as the ellipticity of the pipe. 

2. Using Micrometers: The measurement accuracy of micrometers is higher than that of calipers, making them suitable for situations where high precision in wall thickness is required. When using micrometers, measurements need to be taken at multiple points on the steel pipe. During the operation, it is important to use the micrometers correctly to avoid measurement errors caused by improper operation. 

3. Using ultrasonic thickness gauge: An ultrasonic thickness gauge is a non-contact measuring tool that measures the wall thickness of steel pipes based on the principle of ultrasonic wave propagation in the material. When using it, simply place the probe in contact with the surface of the steel pipe, and you can quickly and accurately measure the wall thickness of the pipe. This method is applicable to various pipe diameters and wall thicknesses of stainless steel pipes, and the measurement results are not affected by factors such as corrosion or oil stains on the surface of the pipe. It can be measured after the installation of the pipe or during its in-service period. 

II. Visual Inspection

1. Observe the end of the steel pipe: After flattening the end of the steel pipe, inspect its cross-section to roughly determine if the wall thickness is uniform. If the wall thickness is uneven, there may be local thickening or thinning. At the same time, observe whether the inner and outer surfaces of the steel pipe end are smooth, and check for any defects such as cracks, burrs, etc., which may also affect the measurement of the wall thickness and the performance of the steel pipe. 

2. Inspect the surface markings of the steel pipe: Regular stainless steel pipe manufacturers usually mark the specifications, wall thickness, etc. on the surface of the pipe. By checking these markings, one can preliminarily determine whether the wall thickness of the pipe meets the requirements. However, it is necessary to pay attention to the accuracy and authenticity of the markings. Sometimes, there may be situations where the markings are unclear or incorrect. 

III. Professional Testing

1. Metallographic Analysis: Metallographic analysis is a method that determines the performance and quality of metal materials by observing and analyzing their microscopic structure. Through metallographic analysis, the metallographic structure of the stainless steel pipe can be observed to determine if the material meets the requirements. At the same time, the wall thickness of the pipe can be measured, and the uniformity of the wall thickness and the presence of internal defects can be examined. 

2. X-ray Inspection: X-ray inspection can penetrate stainless steel pipes and reveal the internal structure and defects of the pipes. By analyzing the X-ray inspection images, the wall thickness of the pipes can be accurately measured, and whether the wall thickness is uniform and whether there are internal cracks, pores, etc. can be detected. This method is suitable for situations where high-quality requirements are imposed on the pipes and non-destructive testing is necessary.