下阀盖 meaning in English

bottom flange
bottom-loading thermobalance

Press down on the cover to assure proper alignment
压下阀盖，确保适当的对齐。
To clean : inspect or replace worn valve disc , disconnect control pipe and unscrew bonnet from valve body using blunt tool and hammer on bonnet lugs
清洗：检查或更换磨损的阀门阀瓣，断开控制管线，采用钝工具和锤打阀盖凸耳从阀体上旋下阀盖。
To clean : inspect or replace worn valve disc , disconnect control pipe and unscrew bonnet from valve body using blunt tool and hammer on bonnet lugs
清洗：检查或更换磨损的阀门阀瓣，断开控制管道，用钝工具和锤打阀盖塞顶部，从阀体上旋下阀盖。