Stem material, and strive to stainless steel stem (2cr13), large diameter valves also should be embedded in the package of stainless steel valve stem.
阀杆材质，力求不锈钢阀杆(2cr13)，大口径阀门也应是不锈钢嵌包的阀杆。
2
Mathematical models for pipe diameter optimization and pump station optimization calculation were constructed, solution to model was determined and LINGO optimization software package was introduced.
建立了管径优化与泵站优化计算的数学模型，确定了模型的解法并引入了LINGO优化软件包。
3
By comparing granules in different specifications of Chinese yam, select best granule diameter, replace the primary artificial package with machine for large batch production.