HBEF (High Blend Ethanol Fuels)
Storage systems for inflamable liquids (e.g. petrol) have to be equipped with flame arresters at all openings.
A flame arrester is a device to stop a flame entering a pipe in case of ignition and is designed to protect the safety of workers, the public, property and the environment.
An “end of line flame arrester” is fitted with one pipe connection only e.g. at the end of a vent pipe.
An “in line flame arrester” is fitted with two pipe connections one on each side of the pipe and has to stop a flame propagation travelling along a pipeline.
Flame arrester is an autonomous protective system (Directive 94/9/EC). To be placed on the marked it needs
a third party (European notified body) approval. An autonomous protective system such as flame arrester
consists a housing, flame arrester elements and a third party approval (to EN ISO 16852).
A flame arrester element or mesh is a flame quenching device that is mounted into a flame arrester. The determination of capillary height and the number of flame arrester elements depend on what they are used for. Therefore a flame arrester element or mesh is not an approved device.
Approved flame arrester has to be marked at the flame arrester body among others with the valid ATEX no. issued from European notified body. Only flame arresters with valid ATEX no. should be placed on the marked (94/9/EC, Chapter I).
Safety characteristics of ethanol (bio alcohol) and petrol are significantly different.
As soon as ethanol is added to petrol (E5,E10...E85) the upper explosions point (UEP) will change.
This means that an explosive gas atmosphere in an storage tank with ethanol will exist across a wider temperature range than in a storage tank with pure petrol.
As there is likelihood that a flammable atmosphere will be present in an Ethanol Petrol Blend storage tank, flame arresters are required in most countries to prevent a flame travelling through pipework into the tank.
Therefore flame arresters are required at all open entries to the tank vapour space including the following positions:
- Liquid delivery line
- The stage 1B vapour recovery connection -
- The stage 2 vapour recovery connection between the dispenser and the vapour return line
- At the end of or in the vent pipe
For storage of petrol and ethanol petrol blends we are offering a wide range of different flame arresters approved in accordance with EN 12874 and EN ISO 16852:
The poppet valve and vapour recovery adaptor is approved as a flame arrestor in accordance
Flame arrester approved to EN 12874 and EN ISO 16852
(e.g. >E90, E100, ethanol diesel blends), IIB2 and IIB3
Ethanol diesel blends and Diesel petrol blends are in test around the globe.
For storage and handling of ethanol diesel blends and petrol diesel blends following has to be considered.
The flash point of diesel is >55°C . The flash point of ethanol is at 12°C and for petrol at < -20°C..
As the flash point of pure diesel is high it makes its ignition risks small.
But things change extremely if diesel contains small amount of alcohol or petrol.
Alcohol and petrol lowers the flash point of the blend sharply and makes it highly flammable under normal conditions.
Under this circumstance storage systems of diesel even with small amount of ethanol or petrol have to be equipped with flame arresters..
In most countries pressure vacuum valve (p/v valve) at the top of vents is required.
Such p/v valve avoids displacement of (VOC) vapours in to atmosphere and reduces contamination of ethanol petrol blends (E5, E10 ... E85) with air humidity.
To open a p/v valve pressure has to be created up to e.g. 30mbar. This 30 mbar pressure doesn’t sound like much, but in nearly empty 10.000 litre storage tank this pressure can create up to 300 litre benzene contained vapours.
Tanker driver, service engineer and forecourt employee are exposed to these vapours several times every day over years. This cannot be a healthy working environment.
For health and safety of workers at petrol station a pressure release valve is available.
Before opening the storage tank, the tanker driver or station manager can release the tank pressure manually through the bypass valve. After realising the pressure the valve is closing automatically and the pressure/ vacuum valve is in charge again.