Airend Installation Procedure

Proper Installation is critical to airend life.

  1. Motor Bearings: install new motor bearings, and inspect covers for wear. If the bearings are loose in the pockets, vibration will be transmitted to the front airend bearings and this will lead to premature failure. 
  2. Drain oil from the system and remove all oil piping, filter housings, sumps, and whatever else holds oil. Clean thoroughly all the components to remove all the old oil and particles. It is important to remove all the metal particles in the system. Most reinstalled airends fail because metal particles left in the machine clog the orifices.
  3. Steam clean oil coolers inside and out.
  4. Replace all filters in system and pre charge the oil lines and oil filter with fresh oil. This can be done with supplying outside air pressure to the sump and flowing through the coolers, oil filters and stop valves. Units with a stop valve will have to be pressurized to keep the valve open. Use a five ( 5 ) gallon container to capture any overflow. At this time you can also check how clean the system is. If any questions, please call.
  5. IMPORTANT: Coupling alignment and placement is critical to airend performance and longer life. Install the new coupling per the manufacturer's installation instructions. There should be a gap on insert type couplings and bolt-on couplings. Make sure that you are not forcing the coupling cushion in place. This will add additional load on the pilot and motor bearings which will cause premature failure. The coupling should be aligned to within .005 both ways.
  6. When installing the airend, cover the inlet to prevent any foreign material from entering the chamber.
  7. Before installing the inlet control, pour fresh oil down the inlet and turn by hand. This will prevent the airend from starting dry. On some units, they may seem stiff, this most likely is caused by the sealer getting on the rotors, it will clear once the unit starts. NOTE: it takes five to ten seconds for the unit to build pressure and force oil through the airend.
  8. Start unit and check for oil leaks and vibration. Let the unit run for about 15 minutes, shutdown and recheck all the oil ports and orifices to make sure there is no blockage.
  9. Restart and change oil filters after the first 50 HRS and then every 500 HRS there after.
  10. Use a good quality synthetic oil for longer life and a cleaner system.
  11. When the airend comes from the factory, they are designed to run within 100 degrees of ambient. If it is eighty degrees outside, the unit should be running at 180 degrees. If you are experiencing high temp., check the coolers, thermal bypass, and oil filter housing. Sometimes the bypass valve breaks apart and blocks the oil flow.
  12. Follow the manufacturers recommendations for all other related services.

If you own a rotary screw compressor and have been faced with the high cost of a factory Airend, you now have a better choice. CMS Airends is one of the largest aftermarket airend rebuilders in the world and has been servicing and rebuilding rotary screw compressor airends since 1977. Our 20,000 square foot facility houses the latest equipment for compressor screw rebuilds. We maintain a complete airend machine shop, fabrication shop, welding shop, and metalizing shop.

Energy costs are rising, and air is a big consumer of energy. If an airend losses efficiency it directly translates into higher energy consumption and thousands of dollars. Your airend is a critical component of your compressed air system.

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