Trunnion Design: Upper and lower supports retain ball under pressure.

耳轴设计：在压力下上下支持阀球。

youdao

Positive and negative pressure existed in the upper and lower drainage pipes.

排水立管的上部和下部都存在正压和负压。

youdao

Positive and negative pressure existed in the upper and lower drainage pipes.

排水立管的上部和下部都存在正压和负压。

youdao