Part 10 – Air Compressor Operations
Maintenance
A maintenance program is developed for each piece of equipment using recommendations from equipment vendors, experience, and consideration of local operating and environmental factors.
Let’s take a closer look at monitoring and preventative maintenance requirements of certain pieces of equipment.
Click on the accordion tabs to learn about monitoring and preventative maintenance.
Compressor Cooling System
A compressor cooling system is necessary to ensure that the temperature of compression is not high enough to decompose or carbonize the lubricating oil. It doesn’t allow the air discharge temperature to rise above 150°C. If untreated water is used, scale in the water jackets, intercooler pipes and other water-cooled parts, may accumulate leading to issues.
High discharge temperatures are often the result of failure of one or more of the discharge valves. If one valve fails, all the valves should be inspected when the repairs are made.
Screw Compressors
Screw compressors require less maintenance than reciprocating compressors because there are only a few moving parts – the screw elements. In an oil free screw compressors the elements do not make contact and therefore there is little wear. With lubricated screw compressors regular oil and filter changes are required.
Dryers
Dryers require an instrument air dew point of a least -40°C is necessary at all times. Dew point analyzers are installed downstream of the air driers.
Things to check when the driers are not functioning properly are:
- Timers or sequence
- Purge air flow
- Drier prefilter and afterfilters
- Temperatures during regeneration
- Total air flow
- Inlet dewpoint can be checked in case upstream coolers are leaking.
Protective Devices
Screw type instrument air compressor:
- Air pressure switches (interstage and discharge)
- Low oil pressure switch
- Low lube oil level
- Low inlet pressure (indicates inlet filter plugged)
- High air temperatures (intercooler and discharge)