B-1.1, r. 2 - Construction Code

Full text
8.96. The vent referred to in section 8.95 must, in the case of a tank that is to contain a Class 1 or Class 2 petroleum product, have a weather-proof hood, and a flame arrester device in the case of a tank that is to contain a Class 1 petroleum product.
Such a device must not create additional resistance to the flow of gases.
The vent must also be connected to the top of the tank by means of piping with a minimum 1% slope towards the tank and the aboveground portion of the vent must be protected from vehicle impact.
O.C. 220-2007, s. 1.