Fluid, petroleum contacts

Microorganisms may be present in hydraulic fluids as a result of contamination during formulation or by inoculation with organisms carried by the air or present on equipment used in handling the fluids. Petroleum hydrocarbons are frequently contaminated by fungal spores which can germinate and generate particulate matter on contact with water. 

The most dominant catalytic process in the United States is the fluid catalytic cracking process. In this process, partially vaporized medium-cut petroleum fractions called gas oils are brought in contact with a hot, moving, freshly regenerated catalyst stream for a short period of time at process conditions noted above. Spent catalyst moves continuously into a regenerator where deposited coke on the catalyst is burnt off. The hot, freshly regenerated catalyst moves back to the reactor to contact the hot gas oil (see Catalysts, regeneration). 

Both the dipolymers and terpolymers have excellent resistance to hydrocarbons found m petroleum-based fuels and lubricants The 69 5% F terpolymer resists swellmg m blended fuels that contain metlianol and can be used in contact with certain phosphate ester-based hydraulic fluids Terpolymers are preferred for contact with aromatic solvents, although either type performs well in higher alcohols VDF-based elastomers dissolve m polar aprotic solvents such as ketones, esters, amides, and certam ethers These elastomers are therefore not suitable for contact with fluids that contain substantial amounts of these solvents because of excessive swell and consequent loss of mechanical properties... 

Mineral Oil Hydraulic Fluids. Studies regarding cancer in humans or animals after inhalation exposure to mineral oil hydraulic fluids were limited to a single case-control study that examined associations between subjectively reported occupational exposure to petroleum-derived liquids and cancer at particular sites among 3,726 male cancer patients (Siemiatycki et al. 1987a). The study found no convincing associations between occupational exposure to hydraulic fluids and cancer at any site. This study is discussed in more detail in Section 2.2.3.8, because, while inhalation exposure was probable for the subject occupations, the authors reported that the exposure route was more often dermal contact. 

Mineral Oil Hydraulic Fluids. Mineral oil and water-in-oil emulsion hydraulic fluids are used extensively in virtually all heavy industries as well as in construction equipment, automobiles, tractors, trucks, and material handling equipment. Potentially exposed populations include workers in heavy and allied industries and the general population due to the use of hydraulic fluids in automobiles however, this profile does not focus on automotive fluids. The most common route of exposure is dermal contact with the neat fluid, although inhalation of oil mists and vapors may also occur. The components of mineral oil hydraulic fluids are present in many other petroleum-derived products including lubricating oils, so exposure to the major components of mineral oil hydraulic fluids is not limited to hydraulic fluid exposures. 

The apparatus used to contact the heavy petroleum liquids with supercritical fluid and for contacting the vaporized materials with molecular sieves is shown in Figure 2. The high pressure chamber is a one-gallon autoclave with a packless magnetically-driven stirrer, manufactured by Autoclave Engineers, Inc. 

The so-called pore pressure transmission-chemical potential test is used in the petroleum industry to assess the osmotic membrane efficiency of a shale in contact with a drilling fluid ([6, 7, 12-1]). It is motivated by the need to assess the capacity of improving the stability of a borehole in a chemically active shale by increasing the salt concentration of the drilling fluid. In this test, a saturated cylindrical sample of shale is subjected sequentially to a hydraulic... 

Poly(a-olefins) or PAOs, polyol esters and diesters are now used in automotive and marine engine oils. To understand how an ester lubricates, it is important to consider its behavior in the different lubrication regimes, especially boundary lubrication when the properties of the bulk lubricant (e.g. viscosity) are of minor importance. The chemical properties of the lubricant responses under extreme conditions will become increasingly important. The polar ester will preferentially stick to the surface of metal when a small amount of ester is added to a low viscosity nonpolar fluid (PAO), (Randles, 1999 Spikes, 1999). When the two metal surfaces come closer together, the polar ester molecules stay in the contact zone. The use of fully synthetic engine oil formulations has produced some improvement in viscosity control and engine cleanliness in the piston and valve train areas over petroleum-based oils (Boehringer, 1975 Frame et ah, 1989 Kennedy, 1995 Lohuis and Harlow, 1985). 

Synthetic oils are somewhat safer than petroleum-based lubricants and do not cause any significant effects to the eyes, skin, or respiratory tract. Continuous exposure has been shown to cause cancer in laboratory animals. Brief or intermittent contact is not expected to pose any significant health problems in humans. Synthetic oils are related to petroleum-based lubricants with one significant difference. Whereas petroleum lubricants contain a variety of carbon chain lengths, synthetic lubricants contain specific compounds and polymers that help them adhere to the moving metal parts to combat friction. Other synthetic oils are used as hydraulic fluids, brake fluids, and antifreeze in automobiles. 

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