Solution
Urea Tank is to store liquid urea, selectively revivify SCR and reduce the ammoniate and oxide challenging are：
1、Liquid inside the tank would tremble together with the car while driving and cause dilation and expansion of the tank；
2、During the tremble, gas, particles and liquid would get into the tank causing contamination and block；
3、High temperature and strong tremble would cause rapid raise of pressure inside the tank, which likely leads to blowout。
Voir’s solution in protective vent:
1、Resistance of water and dust prevents outside liquid and particle from getting inside to block or contaminate；
2、Effective barrier to prevent the urea from spilling and volatilizing under high temperature and tremble；
3、Rapidly releasing the pressure caused by high temperature and tremble and to avoid the expansion and blowout；
4、Both sides venting to prevent explosion by the change of urea and difficulty in supplying urea by the vacuum；
5、Using corrosion resistant material, which is chemical inert, crystallization-free and acid base resistant, so it would not react with urea。
