Compressor Lubrication Tips - Cylinder Oils PDF Print E-mail
Written by Maintenance Technology International inc.   
Saturday, 12 June 2010 10:55
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Compressor Lubrication Tips
Cylinder Oils
Guide to Rotary Compressor Lubrication
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Cylinder Oils

Cylinders used in single and two stage crosshead or trunk type compressors processing air or inert gases, are usually lubricated using the same oil found in the crankcase. When these compressors are used in processing hydrocarbon gases such as methane or butane, or where the compressors are processing "wet" gas containing condensed hydrocarbons or moisture, it is recommended that viscosity grades 320 or 460 be used where discharge pressures are 14,000 kpa (2,000 psi), 21,000 kpa (3,000 psi) and 28,000 kpa (4,000 psi) respectively.

Many sour gas or wet hydrocarbon applications may recommend the use of viscosity grade 460 or 680 oils compounded with 3 to 6% fatty oil to ensure cylinder lubrication. Ensure that cylinders receive the correct oil drop feed rate.

Another factor that determines cylinder oil selection is the operating temperature. Thin films of compressor cylinder oil will inevitably reach the discharge valves. The hot metal surfaces create severe oxidizing conditions and the formation of carbon deposits. These deposits restrict the discharge passages, further increasing discharge temperatures contributing to more deposits. Eventually a hot spot will develop which may result in a fire or explosion.

Lubricant selection and condition monitoring are critical considerations in reciprocating compressor operation and not enough attention is paid to these requirements for safety and insurance reasons.

Last Updated on Saturday, 12 June 2010 11:07