A pressure relief valve and vent assembly include a tank vent including: (i) a vent body having a vent inlet adapted to connect to a tank and arranged to communicate with an exhaust outlet via a fluid passageway; (ii) an exhaust check valve connected to the vent body at or adjacent the exhaust outlet, the exhaust check valve being configured to allow flow in one direction only; and (iii) a pressure relief valve connected to the tank vent inlet and adapted to couple to a tank. The pressure relief valve, when closed, allows for venting air or air/hydrocarbon mixtures from the tank to the exhaust check valve via the fluid passageway. The pressure relief valve, when opened on pressurization of the tank, exhausts tank fluid from the exhaust check valve.