Airend Rebuilding

CMS Airends include the installation of new bearing gaskets, seals, remetalizing and grinding of shafts and rotors, repair to the front and rear housings when necessary, and repair of the sealing strips and oil pump. On Ingersoll Rand, Sullair, Gardener Denver, and Compair encapsulated airends, we will provide new filters and separators. On direct drive units, we service the motor, clean winding, bakeout, and install new bearings and seals. Normal turnaround on our rebuilds is 3 - 5 working days for an average airend.

To see more of our finished work, please visit our gallery.

CMS rebuilds adhere to strict tolerances, use the highest standards to ensure quality, and are backed by a CMS warranty on equipment repaired and defects in materials replaced as well as workmanship for a period of twelve (12) months.

Rotory Screw Compressor Rebuilding Process

What Happens to Your Airend?

  • Your airend is off loaded and taken immediately to the disassembly area which contains mountingstand,overhead crane and oil pit for collecting waste oil.  All shipping documents are then forward to the office to be assigned a work order number, and a folder is generated for disassembly, teardown and spec sheets.  This folder follows the airend through the entire rebuilding process to ensure accurate documentation.
  • Once the airend is disassembled, damage and measurements are recorded, and pictures are taken identifying the problem areas.  A report is generated telling us the front and rear covers were damaged, the sealing strips are partially worn and the bearing journal on the rear is damaged.  The seal area on the unit has groves and a small area of the male rotor bore is out of round.
  • At this point a quote is written for the rebuild and submitted to the customer for approval.
  • The disassembled airend is then placed in one of the self-contained cleaning systems. 
  • Once we receive the OK and Purchase Order number from the customer, all parts that require work are brought to different areas of the shop and the repairs begin.  The front and rear covers will be metalized using the thermal ARC system, when finished depending on the size of the cover, its moved to either the 20” or 36” Blanchard grinder for finishing. 
  • The front male rotor bearing journal is mounted and turned on a lathe and will also be metalized and ground according to specs. 
  • The main bore area if damaged will be plated and bored on a vertical boring mill. 
  • Seal strips are built up and re-cut on a custom jig. 
  • Depending on the extent of the damage, the above work normally takes one to two days to complete. 
  • All components are then rewashed and taken to the assembly area, where all the bearings, seals, gaskets, and related materials needed to complete the assembly are pulled from inventory.
  • Before assemble takes place all the bearing pockets, bores, and alignments are rechecked.  The two rotors are then checked for proper balance and alignment
  • The bearings are removed from the boxes and re-measured for proper fit before installing.
  • To insure that the manufacturer’s specs are being met, the unit is continually measured and re-checked for accuracy 
  • Upon completion all open ports are plugged with plastic caps and the inlet taped.  The airend is now ready to be skid mounted and painted. 
  • As units enter the shipping area all necessary shipping documents and start-up procedures are attached to the unit, and trucking details are arranged. 
  • This whole process will normally take on the average 3 to 5 working days, depending on the MM size and degree of damage.  We have setup our shop so the work flows through on a orderly path to insure that all our inspection steps and quality controls are adhered too.

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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