COMBATING DIRTY FUEL

The fuel system is one of the most crucial and expensive systems in mobile equipment.

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Introduction

Essentially, it is the lifeblood of all construction and mining machines. Fuel costs today are about 80% of operating costs, as against 35% in the 1970s. This cost is the largest expense over the lifecycle of any engine.

Fuel injection system pressure in the 1970s and 1980s was 8700 psi. Today, fuel systems operate at 29000 psi. Even a single foreign particle inside such a high-pressure system can have a devastating effect on various parts and components. That's precisely why present fuel systems demand consistently clean, dry fuel.

The performance and durability of an engine are highly dependent on the fuel's cleanliness. In this article, I highlight a few salient points on how to consistently provide clean and dry fuel.

Clean, Dry Fuel

There are multiple potential sources of contaminants in any fuel system. Following is the extensive list:

• Supply

• Storage

• Handling

• Transfer or dispensing

• Service

• Operation

• Maintenance

Now, it's relatively easy to understand the necessity of providing clean, dry fuel.

Before proceeding further, let's clearly define what it means. The fuel that complies with particle & size distribution according to ISO 4406 is ISO 18/16/13 or less at storage and is considered clean & dry. The cleanliness level is more stringent at the high-pressure pump inlet, ISO 15/13/10. This also includes water contamination because water is detected as a contaminant by a particle counter. However, the Karl-Fischer method may be used separately to quantify water content in fuel. The maximum water content recommended is 500 ppm.