The characteristic of non-destructive testing is that it can be carried out without damaging the material and structure of the specimen, so after the implementation of non-destructive testing, the inspection rate of the product can reach 100 per cent. However, not all items and indicators that need to be tested can be subjected to NDT, and NDT technology has its own limitations. Certain tests can only use destructive tests, so at present NDT cannot replace destructive testing. That is to say, for the evaluation of a workpiece, material, machinery and equipment, the results of nondestructive testing and destructive testing must be compared and matched with each other in order to make an accurate assessment.
Correctly select the timing of the implementation of non-destructive testing: in the non-destructive testing, according to the purpose of non-destructive testing, the correct choice of the timing of the implementation of non-destructive testing.
Correctly select the most appropriate NDT method: Since all kinds of testing methods have certain characteristics, in order to improve the reliability of the test results, according to the material of the equipment, the manufacturing method, the working medium, the use conditions and the failure mode, the expected types of defects that may be produced, the shape, the location and orientation of the defects, and to select the appropriate NDT method.
Comprehensive application of various nondestructive testing methods: any one nondestructive testing method is not omnipotent, and each method has its own advantages and disadvantages. Several detection methods should be used as much as possible to complement each other's strengths and weaknesses in order to ensure the safe operation of pressure equipment. In addition, in the application of nondestructive testing, it should be fully understood that the purpose of testing is not to unilaterally pursue excessive requirements for "high quality", but should be fully guaranteed under the premise of safety and appropriate risk rate, focusing on its economy. Only in this way can the application of non-destructive testing in pressure equipment achieve the desired purpose.
