金屬浮動球閥之設計驗證與分析

Design Verification and Analysis for Metal Floating Ball Valves

張超昀(Chao-Yun Chang)

指導教授 ： 許源泉

國立虎尾科技大學/工程學院/機械與電腦輔助工程系碩士班在職專班/碩士(2015年)

摘要

球閥是食品、石油、化學等工廠之管路設備，控制管線中流體的流向及流量之重要設備，且也是屬於壓力容器之ㄧ，因此歐盟(EN)與英國(BS)、美國(ASME、API)等都有制定相當多的設計標準及檢測規範，使得每個產品都能標準規格化，甚至有歐盟的壓力容器設備指令(PED)的認證，以確保使用操作上的安全。由於台灣生產的球閥比起早期的生產技術與品質提升很多，科技的發展與趨勢使得球閥功能性的要求越來越高，所以球閥的設計驗證及製作過程，可來深入探討及研究。
本研究以美規鑄造不銹鋼(ASTM A351 CF8M=316)球閥作為精密鑄造的材質。先利用3D電腦輔助設計軟體(SolidWorks)，做為整體球閥結構的設計工具，設計過程中結合SolidWorks附加的有限元素分析工具軟體，探討與壓力有直接關係的球閥主要結構件，如閥體(承壓)、閥蓋(承壓)、閥桿(承扭)等的功能性分析驗證。
經由本研究結果在承壓件方面，壁厚的變化是主要因素，在承扭件方面，斷面積的大小是承受扭力的關鍵因素。
因此本研究首先檢測精密鑄造件之材料化學成份、材料機械性質及材料衝擊等試驗分析，其試驗分析所得的數據皆能符合材質規範之標準值內。然後以傳統設計的計算方式為基礎，並透過電腦輔助設計和模擬分析軟體，在施以既定的參數條件下，即可獲得模擬分析的結果，研判後如有缺陷可適時修正與調整其設計，得以縮短其設計開發時程，並有效的驗證最終的結構設計，使球閥能通過相關的檢測規範並符合客戶的產品需求。透過本文對於球閥之設計開發與研究分析，以期能有助於提供產業界與學術界，有著實質的幫助及建議與參考。

關鍵字

球閥 ； 有限元素分析 ； 精密鑄造

並列摘要

A ball valve is an important part for controlling flow directions and capacities of fluids in piping equipment in food processing, petroleum and chemical plants as well as a type of pressure vessels. Therefore, EU (EN), UK (BS) and US (ASME、API) etc. have drawn up a considerable number of design standards and testing specifications to ensure that each product is standardized. There is even certification for compliance to EU’s Pressure Equipment Directive (PED) to ensure safe operation and use. Since ball valves that are made in Taiwan have been greatly improved in production technology and quality compared to the past and technology development and trends have increasingly required better ball valve functionality, it is of value to explore in depth and study the design verification and manufacturing processes for ball valves.
This study used US standard cast stainless steel (ASTM A351 CF8M=316) as the material for investment casting of ball valves. Firstly, the 3D computer-aided design software SolidWorks was used as the tool for designing the overall ball valve structure. In the design process, the finite element analysis simulation module of Solidworks, was used in combination to explore main structural components in a ball valve that are directly linked to pressure, such as valve bodies (pressure withstanding), valve covers (pressure withstanding) and valve stems (torque withstanding) etc. and analyze and verify their functionalities.
Results of the analysis showed that the key factor was change in wall thickness for pressure withstanding components and size of cross-sectional area for torque withstanding ones.
Therefore, the testing in this study first focused on analyzing the chemical composition and mechanical properties of materials used in the investment castings and the impact they could withstand. The data obtained from the testing and analysis were all within the range of standard values described in materials specifications. Then, traditional design calculation methods were used as the foundation in combination with computer-aided design and simulation analysis software for calculations with predefined parameters to obtain results of simulation analysis. This approach allows timely corrections and adjustments to designs if flaws are found and determined, thereby shortening the time for design development and enabling effective verification of final structural designs, which ensures that ball values comply with related testing specifications and meet customer requirements for products. It is hope that the design development and analysis for ball valves described in this paper can offer substantial contributions, suggestions and insights for the industry and academia alike.

並列關鍵字

Ball valve ； Finite element analysis ； Investment casting

參考文獻

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