Man-made damage, due to ill-metal valve design, manufacturing is not fine, improper selection, installation is not correct, use the good and poor maintenance caused by such factors.

人为损坏，是由于金属阀门设计不周、制造不精、选材不当、安装不正、使用不好和维修不力等因素引起的。

youdao

Man-made damage, due to ill-metal valve design, manufacturing is not fine, improper selection, installation is not correct, use the good and poor maintenance caused by such factors.

人为损坏，是由于金属阀门设计不周、制造不精、选材不当、安装不正、使用不好和维修不力等因素引起的。

youdao