Construction Site Best Practices

  • Editorial Team
  • News
  • 25 October 2022

Diesel Exhaust Fluid

Nowadays, it has become necessary to have diesel exhaust fluid present on a worksite. The fluid formulation helps in reducing vehicle emissions. Once exhaust gases have left the engine, the DEF reduces emissions by treating them. Although diesel exhaust fluid has already become a necessity on worksites, it is expected that its importance will increase even more with time. Therefore, you need to learn how to properly use it in order to get maximum performance from your equipment. 

What is Diesel Exhaust Fluid

The composition of diesel exhaust fluid contains a mixture of purified water and urea. The fluid has a stable formula with no toxicity or color, and its pH is similar to that of baking soda. DEF does not serve the purpose of a fuel but rather is used for reducing nitrogen peroxide levels in the exhaust. This helps in ensuring that emission control standards are met. The fluid works by converting NO2 into nitrogen gas and water vapors once it is injected into the exhaust of the selective catalytic reduction system.

How to Store Diesel Exhaust Fluid

On average, the shelf life of diesel exhaust fluid is three years, and it should ideally be stored in a temperature range of 32 Fahrenheit to 86 Fahrenheit. Make sure that the fluid is never exposed to direct sunlight or stored in temperatures below 32 degrees Fahrenheit. Since the diesel exhaust fluid is alkaline, it needs to be stored in plastic or stainless-steel containers. If it is not, it can cause oxidization.

Filling Up the DEF Tank

Standard diesel fuel nozzles would not be able to fit into the diesel exhaust fluid tank opening. DEF tanks are specifically designed in a way to only accommodate DEF fill nozzles. This way, no other fluid can be pumped into the DEF tank. The tank has the capacity to hold between 15 and 50 gallons of fluid depending on your machine’s size and horsepower. If the DEF tank of your heavy equipment is dry, it will stop working, so make sure that you have sufficient diesel exhaust fluid reserves. 

Refilling the Tank 

The latest heavy equipment models and machines are equipped with a DEF gauge that allows the operator to see fluid levels and indicates when it is time to refill the tank. The operator gets a series of warning alerts if the diesel exhaust fluid level is below 10%. If the fluid in the tank is at less than 5% capacity, the engine’s power rating will go down, but there will still be enough power for you to travel a short distance to refill the tank. You only need to refill the diesel exhaust fluid tank once for every three to four times that you refuel your equipment with diesel fuel. However, depending on the operating conditions of your equipment, the frequency with which you need to refill the tank may vary.