紧固性 meaning in English

fastness
tightness

Purpose : to test check valves for tightness in the direction of flow
目的：检测止回阀在流向上的紧固性。
Each packing ring individually inserted and compressed for better tightness
每个垫圈都分别穿入并经过压紧以提供更好的紧固性。
Without live - loading , bolt tightness will be lost , when the system loses pressure
没有动负载，当系统失去压力时，螺栓紧固性就会丧失。
Pressure seal design without live load bonnet ( no spring washers ) : the gasket bolt tightness must be rechecked after operating test pressure and temperature has been achieved
没有动负载阀帽的压力密封结构（没有弹簧垫圈）：在工作试验压力和温度达到限制值时，必须重新检查垫圈螺栓的紧固性。