02 Aug 2016

The fuel tank

Tank is called to petrol storage compartment in vehicles. This piece is in the lower part of the vehicle and is in the safety components family. This piece must have good mechanical resistance against impact and in the event of a disaster gasoline should not leak into the environment. Given the required performance, the fuel tank must have the following characteristics:

  • A secure compartment for storing petrol.
  • When filling petrol in this case it should not create sparks and flow.
  • The case should accommodate a certain amount of gasoline without any leakage.
  • Characteristics of tank volume than gasoline height should be considered.
  • Tap and vapors route for arrival and departure of gasoline from the tank in this equipment should be considered.
  • fueling the engine by a gas station is made from this compartment.
  • It should have high resistance to environmental conditions as well as a variety of possible fuel quality and additives at the entire life of the vehicle. In the automotive industry two types of tanks are used in the design and manufacture of fuel systems. The first group is metal tank that produces the metal fuel tanks using sheet metal forming. The collection is made of stainless steel and connection of components is done with electrode welding. The second group is plastic fuel tanks. The production technology of these fuel tanks is «Blow Molding» and has different production methods. Plastic tanks are usually made of heavy polyethylene and components of these fuel tanks are connected by plastic welding.

Regarding the use of plastic and metal fuel tanks in both Europe and America according to available benefits use of metal fuel tanks in modern automotive design is outdated and almost entire of plastic fuel tanks are being replaced as new and original technologies and only in some cases that circulation of producing a type of vehicle is very low by taking specific measures and accepting limits on design and materials metal fuel tanks are used.

The benefits of polymer tank than metal tank

  • Flexibility in design

By using polymer fuel tanks we can have optimized use of all available space in the car and empty spaces inside the body. Given that the production process of polymer is wind injection and can be produced in various forms, use of free spaces available in the car is created for manufacturer to increase tank volume break by the use of these spaces.

  • Polymer fuel tanks weigh less than metal fuel tanks

In the design of polymer fuel tanks, weight of the fuel tank can be reduced by 40 to 50%. Weight loss has two major influences on the car’s performance as following:

  1. Reduced fuel consumption: per 50 kg lower vehicle weight reduction, fuel consumption is reduced by 2%.
  2. Reducing emission of CO2: per 50 kg of lower vehicle weight, CO2 emission is decreased at a rate of 5 gr/km. According to the new and more stringent requirements of CO2 emission and reducing fuel consumption, increasing reduction of vehicle weight is as one of the main challenges and projects of all automakers in the world.
  • Higher productivity when producing

Polymer fuel tanks with less energy consumption are more efficient for production systems and finally the final consumer.

  • More strength against crash and impact Test

Due to the flexibility of polymers, in the event of severe impacts and crashes, polymer tank has temporary deformation and ward effect of impact off. But in metal tanks, applying similar impacts causes metal rupturing  and thus fuel leakage to the environment or crumpled fuel tank and increasing the fuel pressure and thus explosion. This case was compared in Sled test as Car Crash Stimulation when designing polymer tank by engineers of Irankhodro and according to tests performed at TUV SUD in Germany substantially increased resistance was observed in the polymer fuel tank.

High resistance to wear, corrosion and environmental changes are of the strengths of polymer fuel tanks, resistance to environmental conditions and gasoline, especially alcoholic fuels as well as a variety of additives for fuels is common. Using metal in combined alcohol and gasoline fuel systems or adjacent to water in the fuel, due to high corrosion of metals and internal corrosion is not recommended at all. Also in the external environment adjacent to the open air metal parts will corrode over time that this is exacerbated in salt environments. For example, salting roads when snowing as an undesirable factor would cause accelerated corrosion of the metal tank and extreme risk of leakage.

In addition to achieving the standard level, one of the reasons for removal of using metal tanks in Europe and USA is change in fuel quality to improve engine efficiency and reduce emissions. In standard fuels such as fuel euro, in fuel blends instead of the ring-shaped compounds, the alcohol is used. Due to the use of alcohol in fuel, gasoline acted as an electrolyte solution and has an electrochemical reaction with metal components. This reduces the lifespan of metal tanks, leading to leakage or decay in the fuel tank. This in Iran that car use period is much higher than the world average is more important.

Also, higher efficiency of production of polymer fuel tanks and their reduced energy consumption encourages automakers to use efficient use resources in the supply chain. As it was mentioned polymer fuel tanks because of weight loss and reduced permeability of gasoline reduces fuel consumption and emission of pollutants such as hydrocarbons and carbon dioxide to the environment. This amount for a car during the day may be not considerable but fuel consumption and emissions in Iranian society, with more than 15 million cars per year causes significant digits in savings. By assigning the economies of improving the quality as well as treatment budget cuts, in a preventive measure, government can give this budget to the automakers to achieve blue sky for metropolis of the country.

Social responsibility that is on the country’s automakers to improve the level of safety, quality and environmental of products, led the company to use necessary technological potentials to be commensurate with the strategic initiatives of these industrial groups. Identifying quality problems and social pathologies of vehicles produced in the country in the form of joint projects, new product design and technology transfer in project of X200 polymeric fuel tank assembly has been planned and implemented.