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Wuxi Chuangwei Petroleum Equipment Co.,Ltd

How to measure the length of seamless steel pipe

Release Time:

Jun 17,2022

According to the different process requirements of the manufacturer, the steel pipe length measuring system has a variety of length measuring methods. There are mainly the following:

According to the different process requirements of the manufacturer, the steel pipe length measuring system has a variety of length measuring methods. There are mainly the following:
1. Grating ruler length measurement
The basic principle is that two fixed length grating rulers are set outside the two ends of the steel pipe, and the rod-free cylinder is used to drive the grating ruler close to the two ends of the steel pipe, and the light interference phenomenon is used to measure the length of the steel pipe.
It is characterized by high accuracy. However, the grating ruler is expensive and difficult to maintain, and is sensitive to the impact of dust and site vibration.
2. Camera length measurement.
Camera length measurement is to measure the length of steel pipe by image processing. The principle is to install a series of photoelectric switches with equal distance on one section of the steel pipe conveying roller table, and add a light source and a camera on the other section. When the steel pipe passes through this area, the length of the steel pipe can be determined according to the position of the image captured by the camera on the screen at a certain photoelectric switch.
The feature is that it can realize on-line measurement, and the length data can be obtained when the steel pipe passes through the length measurement area without any interval. The disadvantage is that if the special light source is not used, the steel pipe will be interfered by the external light. However, after the special light source is used, the brightness of the pipe end after chamfering is high and the reflection of light is strong, which is easy to cause reading error.
3. Encoder length measurement
The principle is to install an encoder at the oil cylinder, use the oil cylinder to push the steel pipe to move on the roller table, and install a series of photoelectric switches at the same distance on the other side. When the steel pipe is pushed by the oil cylinder and the pipe end touches the photoelectric switch, the stroke of the oil cylinder is converted from the recorded encoder reading, so the length of the steel pipe can be calculated.
The feature is that the steel pipe needs to be lifted during length measurement. In addition, the photoelectric switch detection also has certain errors, which may require sufficient measurement.
4. Improved encoder length measurement
This method is an indirect measurement method, which indirectly measures the length of the steel pipe by measuring the distance between the two end faces of the steel pipe and their respective reference points. One length measuring trolley is set at both ends of the steel pipe. The initial position is zero and the spacing is L. Then move the length of the editor to the travel distance (L2, L3) of the respective steel pipe ends. L-l2-l3 is the length of the steel pipe.
This measurement method overcomes the difficulties such as the huge volume of steel pipe, the complex production site environment, and the measurement mechanism cannot pass through the lower support platform of steel pipe. This method is easy to operate, the measurement accuracy is within ± 10mm, and the repetition accuracy is ≤ 5mm.