Reduce the risk of boil-over during bitumen loading
Condensed water can build up inside a tank that has been inactive for a prolonged period and cause an incident when it comes into contact with hot bitumen. Similarly, water can get into a tank if a dome cover is left open overnight and this could also lead to a serious incident.
Within just a few seconds of coming into contact with 160oC bitumen, 10 litres of water in the bottom of a tank will transform and expand into almost 20 m3 of steam. This steam will rise up and form hot bitumen foam as it passes through the liquid bitumen under pressure and try to escape from the tank through the restricted section of the manhole.
To avoid this potentially explosive scenario, before loading it is the tanker driver’s responsibility to ensure their tank is free of water or aqueous products, such as bitumen emulsion. If there is any trace of water in the tank, the driver must not use the tank and should immediately notify his operator. Never should bitumen be loaded into a tank containing traces of water.
To help tanker drivers, Eurobitume – in collaboration with the professional association of dangerous goods hauliers in France – has developed an easy-to-follow, four-step plan summarised below and detailed in a handy, two-page document, ‘Recommendations to reduce the risk of boil-over during loading of bitumen’, that can be downloaded from the Eurobitume website here.
The four steps relate to:
- Uncoupling an empty tank on the haulier’s parking area
- After coupling to a tractor unit
- After a test carried out with water, or following prolonged inactivity
- During loading
These recommendations are complemented by the haulier guidelines detailed within Eurobitume’s ‘Loading Compatibility Matrix’, which most drivers will have a copy of in their cab and can be downloaded from the Eurobitume website here.