The selection criteria of reducer respirator consider its adaptability to the environment. The size of the aerator should be adapted to the size of the pressure reducer. When the reducer works, the temperature of the box increases, the gas expands and the pressure increases, which is very unfavorable to the joint surface of the reducer. An aeration device is installed at the top of the box cover or the manhole cover. The gas with thermal expansion in the pressure reducer can freely overflow, and the pressure in the tank remains normal, thus ensuring the sealing performance of the joint surfaces of all parts of the pressure reducer. The inflator is installed on the top of the box cover or the eyelet cover. The perfect aerator is made into a certain labyrinth and equipped with a metal mesh. The above explanation comes from the graduation thesis of turbine and worm reducer design.