fouling

1.He was sent off for fouling the other team's goalkeeper.

他因对对方守门员犯规而被罚出场。

2.A strainer is recommended to be installed ahead of the backflow preventer to prevent the fouling of the check assembly and resulting spillage from the valve during repressurization.

建议在回流阀一过，止由于止回阀总成受到污染而导致这种阀门在再增压期间产生泄漏或溢出。