Diesel and biodiesel engine manufacturers are moving toward electroless nickel plated connectors as part of their fuel system specification. We’ll tell you why.
Meeting the needs of changing material requirements in diesel and biodiesel fuel systems
The transportation and mobile markets always keep performance at the forefront of their specifications, standards and recommendations for truck, bus and other heavy truck applications. As a leading supplier to this market, Parker is committed to responding to the needs of changing requirements.
An increased use of various diesel and biodiesel fuels in heavy-duty fuel systems creates the need to continually assess the compatibility of system materials and the fuels themselves. It has been known for quite some time that B100 (pure) biodiesel fuel can degrade some hoses, gaskets, seal elastomers, glues, plastics, rubber compounds, polypropylene, etc. and the list continues to grow as testing advances. PTFE, Fluorocarbon and Nylon have been known to perform well with B100 biodiesel. B20 biodiesel blends of 20 percent or less have fewer effects on these materials, but great caution in material selection is always important.
Oxidation process of diesel and biodiesel accelerated when using some materials
Recently, it has been noted through further testing that the oxidation process of diesel and biodiesel may be accelerated when using materials such as bronze, tin, lead and zinc. This can create insoluble fuel gels or salts, which can cause blockage in fuel system lines. Heavy-duty manufacturers are responding by eliminating these materials (commonly used throughout the truck for many different applications) as a part of the fuel system.
Brass is comprised of approximately 60 percent copper, 38 percent zinc and 2 percent lead, all materials that are noted to accelerate corrosion with diesel and biodiesel fuels. Copper acts as a catalyst, accelerating the aging of diesel fuel, which creates organic acids. This acid, in turn, corrodes the copper, releasing copper ions that become absorbed in the fuel stream and damage downstream components.
The zinc in brass is also cause for concern due to the fact that diesel fuel, when in contact with zinc or zinc compounds, will become contaminated with low levels of zinc, which can form zinc salts. These salts will tend to form insoluble gels in the fuel and can plug fuel filters, narrow orifices, fuel injector nozzle holes and other small diameter passages within the fuel system.
What is electroless nickel plating?
Parker's Fluid System Connectors Division has responded to the changing diesel and biodiesel fuel system needs. In order to improve performance in the fuel lines, manufacturers must switch to a material that does not oxidize in fuel systems. Stainless steel is an option, but an expensive one. In turn, Parker has electroless nickel (ENI) plated to the fuel wetted surface (the area of the fitting that comes in contact with the fuel) of their brass fuel fittings to accommodate the increasing need for improved performance in the fuel systems.
This provides a very cost effective solution to the problem. While only electroless nickel plating the components in contact with the fuel, the non-fuel wetted components of the fitting can remain brass. The electroless nickel plating prevents corrosion and wear, provides robust chemical compatibility and is approved by all current suppliers that have changed their specifications to accommodate the new requirements. In fact, Parker has the capability to add an electroless nickel plated coating to any brass component that we manufacture.
For more information about our vast offering of DOT transportation fittings, please visit our website or contact Parker Fluid System Connectors Division at (269) 694-9411.
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