Direct-reading type calipers for measuring ovality of pipeline

Abstract

The invention provides a pair of direct-reading type calipers for measuring the ovality of a pipeline. The pair of direct-reading type calipers comprises a calipers body which comprises two calipers legs with the ends hinged to each other through a hinge pin; a rotation angle sensor used for detecting relative rotation angle signals of the two calipers legs is arranged on the hinge pin, a digital display box is arranged on one calipers leg, an integrated circuit board is arranged in the digital display box, a microprocessor used for processing and calculating the angle signals sent by the rotation angle sensor and obtaining a space value between the ends of the two calipers legs is integrated on the integrated circuit board, and a display screen connected with the microprocessor through signals is arranged on the digital display box. The direct-reading type calipers have the advantages that when the direct-reading type calipers are clamped on a bent pipe or an elbow of the pipeline, the number is read without the requirement for taking the direct-reading type calipers out of the pipeline, the angle value is directly read, the calipers legs of the calipers are fastened at largest distance points, and the phenomenon that due to the fact that the distance between the two calipers legs changes, the accuracy of the value is influenced is avoided. An electronic mode and a mechanical mode are used for measuring the angle and errors are reduced.

Description

technical field [0001] The invention relates to a direct-reading caliper for measuring the ellipticity of pipelines. Background technique [0002] Ovality refers to the ratio of the difference between the maximum diameter and the minimum diameter on the same circular section of the elbow or elbow bending part to the nominal diameter. It is one of the items that should be checked during the manufacture and installation of power station pipelines. Due to the existence of ellipticity, under the action of internal pressure, additional stress will be generated, resulting in uneven stress of the pipeline; under the action of external pressure, the stability of the pipeline will be reduced. Therefore, it is very necessary for the safe and stable operation of power plant boilers to ensure that the ellipticity of the elbow or elbow is not greater than a certain value. The measurement of ovality is an important indicator for checking the quality of pipe bends or elbows. According to...

AI Technical Summary

Problems solved by technology

[0004] Disadvantages of the traditional caliper: 1. Since the caliper itself does not have a scale, the maximum or minimum distance point cannot be accurately determined when the other caliper slides along the circumferential direction of the pipe surface. It can only be roughly estimated, which seriously affects the accuracy of the measurement; 2. .Because the caliper itself does not have a scale, after clamping on the pipe bend or elbow, carefully remove the caliper while keeping the distance between the two pliers feet unchanged, and then use a measuring ruler to measure the distance between the two pliers feet. distance between

In the actual operation process, the distance between the two caliper feet is often changed due to the loose fastening screw of the caliper or human touch during the process of removing the caliper, which directly affects the accuracy of the value.

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