LSAW steel pipe is a kind of steel pipe with weld seam parallel to the longitudinal direction of the steel pipe. It is generally divided into metric electric welded steel pipe, electric welded thin-walled pipe, transformer cooling oil pipe, etc. LSAW steel pipe has a simple production process, high production efficiency, low cost and rapid development. The strength of spiral welded pipe is generally higher than that of straight seam steel pipe. Welded pipe with larger diameter can be produced with narrower billet, and welded pipe with different diameter can be produced under the same billet width, but compared with equal length straight seam pipe, the weld length is increased by 30% and 100% respectively, and the production speed is lower. Today, we introduce you how to detect the length of straight seam pipe.

1. scale length measurement, the basic principle is: set up two fixed-length scale on the outer side of the straight seam steel pipe, with a rodless cylinder to drive the scale at both ends of the steel pipe, the use of light interference phenomenon to measure the length of the straight seam steel pipe, featuring high precision, but the scale is expensive, difficult to maintain, and sensitive to the effects of dust and vibration on site.

2. Camera length measurement, camera length measurement is through image processing to achieve the length measurement of steel pipe, the principle is to install a series of equidistant photoelectric switches on one section of the conveyor roller of the straight seam steel pipe, and increase the light source and camera on the other section, when the steel pipe passes through the area, according to the camera captured the image of the position of the screen, according to the photoelectric switches, the length of the steel pipe can be determined. The characteristic is that on-line measurement can be realised and the length data can be obtained when the steel pipe passes through the measuring area without any interval. The shortcomings are: if there is no special light source to irradiate the steel pipe, the steel pipe will be interfered by the external light, and after using the special light source, due to the high luminance of the pipe end after chamfering, the reflection of the light is very strong, which is prone to cause the error of the readings.

3. Encoder length measurement, the principle is to install an encoder at the cylinder, the use of the cylinder to promote the movement of the steel tube in the roller conveyor, the other side of the installation of a series of equidistant photoelectric switch, when the steel tube is driven by the cylinder photoelectric switch at the end of the tube hit, can be converted by the recorded encoder readings of the cylinder's travel, so as to calculate the length of the steel tube, which is characterised by the need to measure the length of the tube to be lifted, and, in addition, the photoelectric switch detection there are Some errors, may need to be fully measured

4. The improved encoder length measurement method is an indirect measurement method, through the measurement of the distance between the two ends of the steel pipe and the respective reference point, you can indirectly measure the length of the steel pipe, the measurement method to overcome the complex environment of the production site, the large size of the steel pipe, the measurement mechanism can not cross the lower support pedestal of the steel pipe and other difficulties, easy to operate, the accuracy of the measurement is less than ± 10 mm, the repeatability of the accuracy is Less than or equal to 5 mm.