Study And Design Of Calibration System For Calibration Bottle In Hydrostatic Test

Cylinder hydrostatic test is the core item in the quality inspection of cylinders.GB/T9251 – 2011《cylinder hydrostatic test method》 and CGA C-1-2009 《methods for pressure testing Compressed gas cylinders》both use external testing method to carry out hydrostatic test,which is used to test whether the overpressure carrying capacity of cylinders meets the use requirements.In order to ensure the accuracy of the test and the validity of the results,the calibration bottle must be used to calibrate the test device before the hydrostatic test of the external test method.therefore,the accuracy of the calibration bottle itself is of absolute significance to the accuracy of the hydrostatic test.This article relies on "Da Gong-Dalian boiler and pressure vessel inspection and research institute engineering practice base" to carry out the design and analysis of the high-precision calibration system for calibration bottles used in the external test method hydrostatic test system.a complete calibration bottle calibration system is constructed and a domestic calibration bottles are calibrated.The main contents and results of this paper are as follows:(1)Analyze the requirements of the calibration bottle in the cylinder hydrostatic test and Improved the test equipment for the calibration bottle calibration test.Determine the measuring range and accuracy requirements of the measuring instrument in the calibration bottle calibration test,and determine the operation steps of the calibration test.A single-point independent calibration and multi-point continuous calibration mode is proposed for calibration tests of multiple points.(2)VB is used as the software development platform,access is used as the background database,word is used as the document processing platform,and the test system is designed according to the requirements of cylinder information management,equipment verification,calibration testing,data processing,and Report requirements.The system uses bar code technology and two-dimensional code technology to realize cylinder management and information storage.Single point independent calibration,multi-point continuous calibration and multi-point continuous depressurization calibration are realized by means of automatic calibration and manual calibration.The system automatically collects,displays and saves test data during the test;At the end of the test,you can query the test data,screen and process the test data,and the final test results will be automatically filled in the report.(3)The single-point independent calibration test and multi-point continuous calibration test are carried out on the same calibration bottle respectively,and the test data are analyzed.it is found that the deviation of the data measured by the two test methods is very small.Therefore,in the actual calibration bottle calibration test,a single point independent calibration or multi-point continuous calibration can be used to carry out the calibration test according to the requirements of the calibration bottle use unit.Through the actual inspection of the national cylinder type test center,it is proved that the calibration precision of the calibration cylinder is stable and reliable,and the repetition rate is good.the calibrated hydraulic pressure test system can effectively detect the pressure-bearing characteristics of the tested cylinder,can replace imported products,and provide the basis for the revision of relevant standards.