How to measure wall thickness of metal pipes?
In the actual use of metal pipes, the whole or local may be subject to corrosion, wear and other destructive effects, so that the metal pipe wall will gradually become thinner, the local thinning of the wall may pose a threat to the safety of the operation of the pipeline. Therefore, the wall thickness of metal pipes is an important indicator in the periodic inspection of metal pipes. The main purpose of testing the wall thickness of metal pipes is to monitor the degree of wall thickness thinning in use, and speculate on the rate of wall thickness thinning, and calculate the service life of the remaining wall thickness. Wall thickness detection methods are numerous, for metal pipe wall thickness detection to metal pipe thickness gauge is most commonly used. Then the metal pipe thickness gauge how to measure the wall thickness of metal pipes?
Metal pipe wall thickness measurement method
1. Metal pipe thickness gauge
Metal pipe thickness gauge, also known as ultrasonic thickness gauge, the use of ultrasonic pulses in the metal material propagation of the round trip time to measure the wall thickness of metal pipes. Linshang ultrasonic thickness gauge with three speed setting mode, you can set the speed of sound according to the known material, you can set the speed of sound known thickness, you can manually set the speed of sound. The three sound speed setting modes can measure many kinds of metal pipes.
Using metal pipe thickness gauge measurement before, to be measured on the surface of the metal pipe processing, remove the metal oxide layer on the surface of the pipe, rust, etc. to ensure that the measured surface is free of dirt and flat. Measurement, the need to apply the appropriate coupling agent on the surface of the metal pipe, and the instrument's double crystal probe should be measured coaxially with the surface of the pipe to be measured.
2. Ultrasonic flaw detector
The use of ultrasonic flaw detector for thickness measurement generally choose high frequency small lens longitudinal wave straight probe, if the metal pipe surface coupling condition is not good, ultrasonic flaw detector can obtain more ideal detection results. Through the ultrasonic flaw detector with the appropriate chip size probe sweeping the pipe wall, you can qualitatively understand the wall condition through the waveform characteristics.
When the pipe wall is uniformly smooth without thinning, the ultrasonic waveforms are equally spaced and linearly decreasing in amplitude, and the adjacent echo spacing is the thickness of the pipe wall. If there is serious corrosion and other defects in the inner wall of the pipe, the ultrasonic waveform is more chaotic, and the waveform changes more with the movement of the probe.
3. Radiography method
Radiography method can not directly quantify the thickness of the pipe wall, but can visually obtain the shape, size, density of the inner wall defects. Through the use of trench contrast test block. Can determine the depth of wall thinning, the severity of local wear of the pipe.
Radiography method is more complex process, the required detection time is longer, the detection cost is higher, therefore, radiography method is generally used for ultrasonic can not accurately determine the existence of thinning when confirming the pipeline situation.
Advantages of metal pipe thickness gauge
1. Small size of the instrument, easy to carry, few keys, simple operation, easy to start for novices.
2. Measurement response time is fast, can quickly produce results, digital display screen can quickly read the number.
3. High precision, wide measuring range.
4. With QC determination function, independent setting of upper and lower limit values, can quickly determine whether the tube wall thickness qualified.
The above is the introduction of metal pipe wall thickness measurement of all content, measurement of metal pipe wall thickness on the choice of Lin on the metal pipe thickness gauge, high precision to ensure that it can pass the national metrology institute testing, three models with super cost-effective, three speed of sound setting mode to cover many materials, two measurement modes to meet the data statistics and QC judgment needs, your best choice!