Lubrication, compressors

Injection gas pressures are usually much higher than lift-gas or gas pipeline pressures and special care has to be taken to select compressor lubricants that will not dissolve in high pressure gas. Such a situation could lead to inadequate lubrication and may impair well injectivity. 

Alkylated aromatics are used as the base fluid ia engine oils, gear oils, hydrauHc fluids, and greases ia sub2ero appHcations. They also are used as the base fluid ia power transmission fluids and gas turbine, air compressor, and refrigeration compressor lubricants. 

Halogenated hydrocarbons that are inexpensive sometimes are used alone or in blends with phosphate esters as fire-resistant hydrauHc fluids. Other halogenated fluids are used for oxygen-compressor lubricants, lubricants for vacuum pumps that are in contact with corrosive materials, solvent-resistant lubricants, and other lubricant appHcations where highly corrosive or reactive materials are being handled. 

Miscellaneous Commercial Applications. Dimer acids are components of "downweU" corrosion inhibitors for oil-drilling equipment (see Petroleum Corrosion and corrosion inhibitors). This may account for 10% of current dimer acid use (71). The acids, alkyl esters, and polyoxyalkylene dimer esters are used commercially as components of metal-working lubricants (see Lubrication). Dimer esters have achieved some use in specialty lubricant appHcations such as gear oils and compressor lubricants. The dimer esters, compared to dibasic acid esters, polyol esters and poly(a-olefin)s, are higher in cost and of higher viscosity. The higher viscosity, however, is an advantage in some specialties, and the dimer esters are very stable thermally and can be made quite oxidatively stable by choice of proper additives. 

Industrial lubrication Machine tools and metal cutting Lubricants for heavy industry Gear lubrication Hydraulic fluids Machine shop lubricants Cutting fluids Compressor lubrication Greases... 

Another example would be the use of naphthenic oils in the formulation of compressor lubricants, textile processing oils, and other industrial lubricants. In these formulations, solubilizing and dispersing compounds within an oil is quite important. 

Fig. 4.1-29. Power range of various compressor types for high-pressure [24], D, Diaphragm compressor PI, Piston compressor, dry running (piston ring, labyrinth) P2, Piston compressor, lubricated (piston ring) P3, Ultra-high-pressure compressor, lubricated (plunger piston) TR, Radial turbo-compressor TA, Axial turbo-compressor S, Screw compressor.

Compressed air is one of the utilities that may have direct or incidental product contact and therefore requires qualification. The types of contaminants found in compressed air, not surprisingly, are the same as those found in the ambient environment. These may include micro-organisms (e.g., bacteria, molds, and viruses), moisture, particulate matter, and possibly pyrogens. Undesirable levels of hydrocarbons from compressor lubricants may be found if the compressor is not of the oil-free type. 

Use High-temperature lubricants, low-temperature fluids, compressor lubricants, hydraulic brake fluids, quenchant fluid, heat-transfer fluids, textile lubricants, rock drill lubricants, leather and papertreating compounds, rubber lubricants, plasticizers and solvents, chemical intermediate, stationary phase in gas chromatography. 

Compressor oils This market sector covers a wide range of compressor types used for a number of different gases. Diesters and phthalates have found their major application in air compressor lubricants and are also used in natural gas compressors. In reciprocating compressors, where oils of rather higher viscosity are preferred, trimellitate esters can be used. Diesters and polyol esters may also be blended with PAOs for use in various compressor types. 

Typical application areas are industrial gear oils and greases, compressor lubricants, metalworking fluids, aqueous quenching fluids, fire-resistant hydraulic fluids, textile lubricants and heat transfer liquids. Section 2.7.5 gives a detailed account of these applications. 

Compressor lubricants Lubrication in the pressurised area of a compressor presents many problems. Lubricants must not only seal, cool and reduce friction and wear but also cope with the presence of compressed aggressive or oxidising gases. 

To simplify industrial lubricant classification, the names of lubricants such as bearing lubricants, compressor lubricants, hydraulic lubricants, gear lubricants, metalworking lubricants, etc., derive from their application. These classifications are consistent with other lubricant categories, i.e. lubricants for internal combustion engines, aviation lubricants and marine lubricants. 

The three main groups of compressor lubricants are for (i) gases, (ii) refrigerators and (iii) vacuum pumps. Depending on the application, various classes of lubricating oils are used, including mineral oils of various levels of refinement, semi-synthetic and/or synthetic oils. Some lubricants for gas compressors may contain a wide variety of additives. 

For long-term hydrolytic stability and exceptional water separation, polyalphaolefins are the preferred rotary compressor lubricants. The energy cost savings... 

Table 8.4 Compressor lubricant product selection variations [48]...

Voitalrf. [Atochem N. Ant Afochem UK] ChlototrifluoroethyleK oils lubricant EP additive used ftur compressor lubricants, hydraulic fluids, pump fhtids, danqung fluids, heat transfer fluids. 

Ethylflo. [Ethyl] Pdyalphaolefins synthetic lubricants for automotive crankcase oils, hydraulic fluids, gear and transmission fluids, compressor lubricants, metalwtaldng fluids, personal care items. 

ZeroL [ShrieveQiem. Prods.] Refrigeration compressor lubricant... 

Uses Corrosion Inhibitor for copper, aiuminum, and steei in hydrocarbon systems, lubricants, metatwor1[Pg.201]

Chem. Descrip. Linear polymer of all oxypropylene groups Uses Component of adhesives used in articles intend for food confacf component of surf, lubricanfs in mfg. of mefallic arfides in confacf wifh food base fluid for formulafed compressor lubricants rubber lubricant coating for hydraulic brake parfs and similar equip. reaefive infermedi-ate in preparation of resins, plasticizers, modifiers, and surfaefants antifoam... 

Compressed air lines are often fitted with filters, regulators, and lubricators. These are usually installed as a set. The filter may be of standard design, to remove moisture and solids, or a coalescing filter, to remove aerosols of compressor lubricating oil. The purpose of the regulator is to adjust the pressure of the air. The lubricator injects a small amount of oil, which provides downstream lubrication. The regulator is mounted between the other two appliances so that it wUl handle only clean air. 

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