Method For Measuring the Length of SSAW Steel Pipe

SSAW steel pipe is made by rolling low carbon carbon structural steel or low alloy structural steel strip at a certain helical angle (called forming angle) into a tube blank, and then welding the pipe seams. Steel produces large diameter pipes. Its specifications are expressed by outer diameter * wall thickness, and the welded pipe should ensure that the hydraulic test, the tensile strength of the weld and the cold bending performance meet the requirements.

Length measurement method of ssaw steel pipe

1) Camera length measurement

The camera length measurement is to use image processing to measure the length of the steel pipe. When the steel pipe passes through this area, the length of the steel pipe can be determined according to the position of a photoelectric switch on the screen where the image is captured by the camera.
 
The feature is that it can realize online measurement, and the length data can be obtained when the steel pipe passes through the length measurement area, without interval. The disadvantage is that if the special light source is not irradiated, the steel pipe will be disturbed by the external light. After the special light source is used, the light reflection of the steel pipe is very strong due to the high brightness of the pipe end after the chamfer, which is easy to cause reading errors.

2) Length measurement with grating ruler

The basic principle is: two grating rulers of fixed length are set on the outside of the two ends of the steel pipe, and the rodless cylinder is used to drive the grating ruler to be close to the two ends of the steel pipe, and the length of the steel pipe is measured by the interference phenomenon of light.

It is characterized by high accuracy. However, grating scales are expensive and difficult to maintain, and are sensitive to the effects of dust and site vibration.

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 equal distances on the other side. , convert the stroke of the cylinder, so that the length of the steel pipe can be calculated.

The characteristic is that the steel pipe needs to be raised when measuring the length. In addition, photoelectric switch detection also has certain errors, which may require adequate 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 the respective reference points. A length measuring trolley is set at each end of the steel pipe, the initial position is zero, and the distance is L. Then move the editor length to the walking distance of the respective steel pipe ends (L2, L3), L-L2-L3, which is the length of the steel pipe.

This measurement method overcomes the difficulties such as the large volume of the steel pipe, the complex production site environment, and the inability of the measuring mechanism to pass through the lower support bench of the steel pipe. This method is easy to operate, the measurement accuracy is within ±10mm, and the repeatability is less than or equal to 5mm.

Article source: https://article-realm.com/article/Internet-Business/Security/20597-Method-For-Measuring-the-Length-of-SSAW-Steel-Pipe.html