Urea – More Things to Consider

Urea - More Things to Consider

I recently heard a new concern for those of you who will be storing and dispensing Urea for the 2010 diesel trucks. Urea is a very corrosive product that can quickly damage metal tanks, some types of seals, even dispensing nozzles.

Most fuel dispensing nozzles are made from nickel plated aluminum. When Urea is dispensed through such a nozzle, the nickel plating will react changing the Diesel Emission Fluid (DEF) to where it can cause damage to the SCR (Catalytic Converter) system.

The longer the Urea is in contact with the nozzle the more potentially damaging the fluid will become. What this means is that in high volume situations, the fluid will have limited contact with the nozzle and the likelihood of fluid being contaminated is significantly reduced. In lower volume situations where there may be extended periods of time between use, there is a higher likelihood of contaminating the fluid.

It may be desirable to go to a nozzle made of unplated metal or possibly even a composite material to prevent this contamination.

It is considered vital that a non-fuel nozzle be used to prevent the possibility of accidentally adding diesel to the DEF or DEF to the Diesel Fuel. Either mistake will likely cause rapid and catastrophic failure of the engine and or the SCR System.

In Europe a company called ElaFlex provides the defacto standard for AdBlue (Urea) nozzles that have a unique feature that prevents the AdBlue (Urea) from being added to the fuel tank.

ElaFlex has recently signed an agreement with OPW to provide these nozzles to the US and Canadian markets.

We will be providing a comprehensive list of suggestions on how to safely and cost effectively dispense Urea for your fleet operation.

Diesel Doctor

Copyright 2009 – William Richards

UREA use in 2009 and 2010 Diesel Vehicles

Urea Use in 2009 Light Duty and 2010 Medium and Heavy Duty Diesels

Hold on, here comes the next big change in diesel engines. Starting with the automotive market in 2009 and then with virtually all of the medium and heavy duty diesel vehicles in the 2010 model year, diesel engined vehicles will require an additional fluid to operate.

These vehicles will require an “aqueous urea solution” as defined by ISO 22241-1 using test methods described in ISO 22241-2:2006. This is a solution of 32.5% Urea in deionized water.

This Urea solution is used as part of a Selective Catalytic Reduction (SCR) system to reduce the NOx emissions of diesel fueled engines.

These systems require that a tank of the Urea solution be installed on the vehicle. The Urea is meter injected into the exhaust stream after the turbocharger where the exhaust heat will convert it to ammonia which is then used by a special type of catalytic converter to significantly reduce the formation of NOx. This system will function as long as there is Urea available.

This is a complicated system with maintenance requirements, cold weather operability issues (Urea freezes), and quality concerns.

There is a wide ranging debate on what type of driver information systems are to be required, what will happen if the system runs out of the Urea solution, and where Urea will be available.