The basic principle of stage 1B vapour recovery is to control the vapour released from the filling station storage tanks during the unloading procedure from the road tanker. This is achieved by diverting the vapour displaced through the tank vent back to the road tanker for removal from the site and subsequent recovery at the distribution terminal.
The vapour recovery system will have one tanker connection point which can be below or above ground which will come complete with a poppet self-sealing adaptor and a flame arrester approved to EN ISO 16852.
The petrol vent lines will then be manifolded together. This can take place above or below ground allowing vapour to be returned from all the petroleum product tanks to the road tanker upon delivery. A pressure/vacuum vent valve will be fitted to the vent stack to allow vapours to be retained in the petrol tank system. This valve will operate at a blow-off pressure of + 35 mbar and – 2 mbar vacuum to allow air to be drawn in as fuel is being dispensed.