To maintain the spool in the head and valve seat rings for tight closure is important.

保持阀芯头与阀座环对中，对于严密关闭是重要的。

youdao

To maintain the spool in the head and valve seat rings for tight closure is important.

保持阀芯头与阀座环对中，对于严密关闭是重要的。

youdao