An In-Position Measurement Method of Point Replacing Surface for Triple Eccentric Butterfly Valve Precision Machining

Abstract

Abstract The machining quality of sealing surface of triple eccentric butterfly valve is crucial to its the sealing performance. Especially, the measuring of sealing surface size is the key to assess the machining quality. Due to the special structure of triple eccentric butterfly valve, the sealing surface size of triple eccentric butterfly valve is difficult and inaccurate to measure in position, which makes it difficult to ensure the machining quality of triple eccentric butterfly valve sealing surface. This will affect the sealing performance of triple eccentric butterfly valve, and result in poor bidirectional sealing, non-interchangeability, and lower machining productivity of the bodies and discs. Based on the above problems, this paper proposes a new measuring method for sealing surface size, i.e., in-position measuring method of point replacing surface. The reliability of method is analyzed and proved from the level of design principle of triple eccentric butterfly valve. Further, the tooling fixture and in-position measuring device of sealing surface size are designed and manufactured based on the measuring method of the point replacing surface. Different from the existing assembling boring process, this paper designs and manufactures a new boring tooling fixtures and develops an integrated process of measuring and machining. After the preliminary measuring and machining test, the reproducibility of the results was good, parts interchangeability and bidirectional sealing could be realized. And the application of this machining process significantly shortened the machining time and increases the machining efficiency by 25%.