This option will be exercised only in the presence of a significant number of weld repairs .

只有出现大量 补 焊时才行使该选项。

Fittings requiring weld repairs are unacceptable .

不得采用需要进行 焊 补的配件。

After weld repairs however the overall quality and reliability of a cast valve is difficult to determine .

但是，在 焊 补后，铸件阀门的整体质量和可靠性就变得难于保证。