Paul I. Lacey

Survey of Low Sulfur Diesel Fuels and Aviation Kerosenes from U.S. Military Installations

Abstract : In support of the Department of Defense goal to streamline procurements, the Army recently decided to discontinue use of VV-F-800D as the purchase specification for diesel fuel being supplied to continental United States military installations. The Army will instead issue a commercial item description for direct fuel deliveries under the Post/Camp/Station (PCS) contract bulletin program. In parallel, the Defense Fuel Supply Center (DFSC) and the U.S. Army Mobility Technology Center-Belvoir (MTCB at Ft Belvoir, VA) initiated a fuel survey to assess the general quality and lubricity characteristics of low sulfur diesel fuels being supplied to military installations under the PCS system. Under this project, diesel fuel delivery samples were obtained from selected military installations and analyzed according to a predetermined protocol. The results obtained from various tests show that the average, low-sulfur diesel fuel meets military requirements for DF-2 with the exception of lubricity performance. Proposed fuel lubricity requirements for military, ground-vehicle, diesel fuels are presented.

Tribological Properties of Fire-Resistant, Nonflammable, and Petroleum-Based Hydraulic Fluids

Petroleum-based hydraulic fluids qualified under MIL-H-6083 are highly flammable. As a result, a fire-resistant polyalphaolefin (PAO)-based fluid, qualified under MIL-H-46170 and developed in the 1970s, and more recently, a nonflammable chlorotrifluoroethylene (CTFE) hydraulic fluid, were developed as potential replacements. However, the chemical and physical properties of both fluids are significantly different from those of conventional fluids. This paper outlines a laboratory study to define the interrelated parameters of degradation and wear of contacts lubricated with various hydraulic fluids, with particular reference to CTFE. The results rank the likely wear, corrosiveness, and oxidation properties of CTFE in comparison to currently used silicone-, PAO-, and petroleum-based fluids. In general, the antiwear characteristics of the CTFE hydraulic fluid were found to be similar to those of petroleum-based fluids but marginally inferior to those of PAO-based fluids. However, CTE produced severe corrosion of brass at temperatures above approximately 135 C. As a result, it is believed that operation at very high temperatures is likely to cause unacceptable material removal from copper-based metals. Several surface treatment processes were identified to minimize potential side effects, evident under more severe operating conditions with CTFE.