Repsol YPF

Gas-oil tanks

The storage of petroleum derivatives for combustible use, such as gas oil or fuel oil, requires products with high resistance to the permeability of the most volatile compounds, in addition to high degree of stiffness since these storage tanks will have a large capacity, up to 5000 litres. Therefore, the raw material which composes the container should be homologated for this purpose, whether or not the already transformed body also needs to overcome certain tests prior to its approval.

The high density polyethylene used for this application must guarantee its prolonged exposition to the outdoors without deterioration of its colour nor its mechanical properties. Therefore, it should incorporate a stabilizing additive with regard to ultraviolet radiation.

The best resistance to the outdoors is achieved by adding carbon black. So, with a content of 2 - 3% of carbon black, evenly distributed in the polyethylene mould, this property is improved in a factor superior to 15.

White and chromatic pigments can improve the stabilization in regard to solar radiation in polyethylene, but they can, equally, harm it.

The following Hdpe grades are specially designed for this application, are homologated to remain in contact with oil products:

• Alcudia 49070-UV
• Alcudia 45060-UV