Krampitz Safety Features Part 8: gasoline vapor recovery system

All Krampitz tanks and tank containers for highly flammable media have a Gasoline Vapor Recovery system.
Therefore, there are always two related connections for the filling process in the filling niches for highly flammable media: a connection for fuel filling and a connection for Vapor Recovery.
The Vapor Recovery prevents fuel gases from escaping during filling at our filling stations.
This is how the system works:
When filling from the tank truck, two hoses are connected: the filling hose to the filling connection and the vapor return hose to the Vapor Recovery connection.
When filling the tank, the fuel-air mixture that is above the fuel liquid is displaced. Instead of leading it out, however, the fuel-air mixture is returned to the tank truck via the vapor return line.
This prevents the dangerous gases that are harmful to health and the environment from escaping.
As an additional protective measure, a safety relief valve is also installed at our filling stations.
The safety relief valve equalizes pressure differences.
This is because overpressure or underpressure can occur in the tank.
Overpressure occurs when the tank is filled or when the tank heats up in warm outside temperatures.
Underpressure, on the other hand, occurs when fuel is removed - for example when refueling.
Without a safety relief valve, pressure equalization would have to take place via an open ventilation pipe. However, this would constantly cause uncontrolled fuel gases to escape.
This does not happen with the safety relief valve! And this is how it works:
The safety relief valve has a vacuum module and a overpressure module. In normal operation, both valves are closed by metal balls. Fuel gases cannot escape.
The overpressure valve only opens when overpressure occurs in the tank - for example when filling- and reaches the threshold of 22 millibars. Then the pressure is strong enough to lift the ball.
The pressure can escape and the ball then closes the valve again.
The vacuum module works in the same way. When fuel is removed, a vacuum is created, a suction. From minus 17 millibars of negative pressure, the suction is strong enough to lift the ball and thus open the valve. Air flows in from the outside, pressure equalization takes place and the vacuum is reduced. The ball then closes the valve again permanently.
Whether it is overpressure or underpressure, in real time pressure equalization takes place extremely quickly. The valve is open for half a second, but then permanently closed again. The tank is sealed. Gases can only escape when the pressure is equalized and contaminants stay outside.
The safety relief valve and Gasoline Vapor Recovery system protect people and the environment from harmful fuel gases and make Krampitz gas stations so safe.
Krampitz tank system - cubically good
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