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.

建议在防回流阀前安一个过滤器，防止由于止回阀总成染而导致这种阀门在再增期间产生泄漏或溢出。

This device should be installed at the furthermost downstream end of the supply pipe or fixture where temporary spillage due to critical flow pressure conditions can be discharged harmlessly.

这种该安在供管道或卫生洁具下游尽可能远，并且由于临界水环境可能产生无害排放的暂时性喷溅的地方。