The Cumulative Error Control In The Hard Seal Butterfly Valve Machining Process

Butterfly valve, as a kind of piping components which used to implement the piping system on-off and flow control, is widely used in many fields, like petroleum, chemical industry, metallurgy, water and electricity. Especially in large and medium caliber and the use of low pressure area, butterfly valve has become the dominant form of the valve.This article is based on the double eccentric flange hard seal butterfly valve size DN600 as the research object. In the key parts of seal structure, the valve disc is ductile iron carbide surfacing material, the valve seat is 0Cr18Ni9(304)nitriding processing material after processing. The research object has a hard seal butterfly valve features of high temperature resistance, wear resistance, good mechanical properties, but poor sealing effect. The article research and demonstrate from the following three parts.First, the structure of the research object, the key influence factors and key parts structure is analyzed; factors affecting the hard seal butterfly valve quality process is analyzed. Through the process of factors influencing the effect of interference between the valve disc and valve seat, find the key positions and key component parameters, Found through analysis of key parameters influence the key factor in the process of hard seal butterfly valve processing and manufacturing.Then, through analysis on factors affecting, measuring the main positions data through processing. Using error control method.The error of the measured data by using normal distribution analysis method, the result of the analysis. to find the way to control the accumulated error in the process of machining. Through the analysis and research of the control method, to develop a reasonable machining method. Obtain a new positioning mode and new processing method to change valve disc processing technic. And by improving the processing methods of analysis and research, analysis of CNC programming, numerical control processing method, Eventually to control the cumulative error of machining process of main posions in hard seal butterfly valve.At last, to validate the new machining method and sequence and in the actual machining, through measuring the main positions data to verify. Determine the improved method is feasible. Finally it is concluded that hard seal butterfly valve cumulative error control method of machining process. In order to achieve the purpose of this study.