The upper set of wrench flats belong to the packing nut, which is threaded into the valve body.

扳手面上面的那个属于衬垫螺母，它是通过螺纹旋进阀体的。

youdao

The upper set of wrench flats belong to the packing nut, which is threaded into the valve body.

扳手面上面的那个属于衬垫螺母，它是通过螺纹旋进阀体的。

youdao