很简单，使避雷器寿命延长，避雷器本体没有较高的持续运行电压。电压基本都加在间隙上。
Simply, the life of the arrester is prolonged, and the arrester itself does not have a high continuous operating voltage. Voltage is basically applied to the gap.
一般线路避雷器采用带间隙的避雷器，线路避雷器一般都在野外，山上。进行预防性试验和维护都很困难。
Generally, line arresters adopt lightning arresters with clearance. Line arresters are usually in the field and in the mountains. Preventive testing and maintenance are difficult.
线路避雷器的串联间隙一般分为，绝缘子间隙和空气间隙两种。
The series clearance of line arrester is generally divided into insulator clearance and air clearance.
线路避雷器主要保护绝缘子串减少跳闸率。
Line arrester mainly protects insulator strings to reduce trip rate.
另外以往的阀式避雷器，碳化硅避雷器也有带间隙的，不过都是内置的间隙。
In addition, the previous valve arresters, silicon carbide arresters also have gaps, but are built-in gaps.