Thick-walled seamless pipes are produced by cold drawing and hot rolling, and are categorized by material as ordinary and alloy pipes, and by use as structural seamless steel tubes, conveyance seamless steel tubes, boiler seamless steel tubes, high-pressure boiler seamless steel tubes, high-pressure seamless steel tubes for fertilizer equipment, seamless steel tubes for geological drilling, seamless steel tubes for petroleum drilling, seamless steel tubes for petroleum cracking, seamless steel tubes for ships, cold-drawn and cold-rolled precision seamless steel tubes, and various alloy pipes. thick-wall steel pipe seamless have multiple length measurement methods based on the manufacturer’s requirements for small-diameter thick-walled steel pipes. The primary ones are:
The basic principle is to install two fixed-length grating rulers on the outer sides of both ends of the thick-walled seamless steel tube, using a rodless cylinder to drive the grating rulers towards both ends of the steel pipe, and using the interference of light to measure the length of the steel pipe. The main feature is high accuracy. However, grating rulers are expensive and difficult to protect, and thick-walled steel pipes are sensitive to dust and site oscillations.
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 conveyor, and install a series of photoelectric switches at equal intervals on the other side. When the steel pipe is pushed to the side of the photoelectric switch by the oil cylinder, the encoder reading is recorded, and the travel of the oil cylinder is calculated to determine the length of the thick-walled seamless steel tube. The main feature is that the steel pipe needs to be lifted during measurement. In addition, there may be certain errors in the photoelectric switch detection, and full measurement may be necessary.
Camera measurement uses image processing to measure the length of thick-wall steel pipe seamless. The principle is to install a series of photoelectric switches at equal intervals on a section of the steel pipe conveyor roller, and add a light source and camera on the other section. When the steel pipe passes through this area, the length of the steel pipe can be determined based on the position of a photoelectric switch captured by the camera and displayed on the screen. The main feature is that online measurement can be completed, and length data can be obtained when the steel pipe passes through the measuring area without interruption. The drawback is that if there is no need for a special light source for illumination, thick-wall steel pipe seamless will be disturbed by external light, and if a special light source is used, reading errors may occur due to the high reflectivity of the steel pipe surface.
This method is a direct measurement method that measures the distance between the two end faces of the steel pipe and their respective reference points to directly measure the length of the steel pipe. One measuring cart is installed at each end of the thick-walled seamless steel tube, with an initial position of zero and a distance of L. Moving the encoder length to the travel interval of each steel pipe end is the length of the steel pipe.
