Relief valves with flame arrester
HSG176 – Emergency venting can be handled by a number of different methods:
Relief Vales c/w Flame Arrester
Pros: One vent to handle both normal & emergency conditions
Ultimate protection from external ignition sources
Sealed unit with no easy access to tank product
Product loss reduced by relief valve
Cons: Extra equipment increases maintenance costs
Capacity of relief valve may dramatically increase connection size
Weight of assembly must be taken into consideration
When a flame arrester with a PVRV is installed on a tank of 47 m3 (a small storage tank stored AV69%), the pure ethanol of more than 1 kg can be saved every week, that is, more than 2.5 bottles of 70 cl final products/per week can be saved based on the daily average ambient temperature of 16 °C.
If the daily average ambient temperature slightly increased, the product savings would significantly increase.
Emergency relief vents are fitted to storage tanks to allow emergency ﬂow due to the excessive venting requirement from a fire burning around a storage tank.
This eliminates a costly and dangerous tank rupture, providing emergency venting from abnormal internal pressure beyond the capability of the pressure relief vent.
In the event of a fire, the internal pressure will increase dramatically, lifting the pallet at a pre-determined pressure, thus supplying a large venting area.