Reconditioning of hypercompressor carbide plungers

Hyper compressor carbide plungers are the most critical parts in the LDPE production. A catastrophic plunger failure leads to unplanned compressor shut-down. This will not only entail enormous production losses, but also extensive repair costs of other compressor parts and in the worst case this can lead to severe personnel injuries caused by an explosion.

Hyper compressor plunger defect analysis

In order to avoid catastrophic failures the carbide plungers have to be inspected and reconditioned on a regular basis. The primary goal of our reconditioning service is to prevent plunger fracture during production.

Therefore CTD does more than just grinding and polishing! Based on our knowledge about hyper compressor cylinders and our know-how of plunger defects and their causes, we can inform our customers about possible compressor problems by analysing the plunger surface. With a average of more than 150 plungers every year, we have seen all possible defects!

Used techniques

  • microscopic inspection (>120 x)
  • fluorescent dye penetrant
  • eddy current
  • ultrasonic inspection

Carbide plunger grinding

CTD has invested in a state of the art high precision CNC grinding machine for grinding of solid carbide plungers. With this machine we are able to grind your plungers up to 1500 mm length within 2-3 µm diameter difference over the complete length. Grinding is necessary to remove wear, corrosion and to restore dimensional accuracy. This will reduce wear on your packing rings and reduce bronze deposition on the plunger. Another advantage of grinding is that it induces compressive residual stresses in the surface layer which will reduce crack initiation and thus the risk of plunger failure. Read more about plunger grinding: ASME PVP2013-97854: Cemented Carbide Plungers for Hyper Compressors: Properties, Defects and Reconditioning

Carbide plunger superfinishing

After grinding the carbide plungers are superfinished to a roughness lower than Ra 0.005 µm in order to avoid any unwanted friction between plunger, packing rings and guide bush. A highly polished surface makes it also possible to detect every defect during microscopic inspection.

Experienced operators

Our skilled operators have many years of experience in plunger reconditioning. No company refurbishes more plungers than CTD! That is why we know how to handle your plungers correctly throughout the entire reconditioning process from cleaning, inspection, grinding, polishing to packing and shipping. Your plungers are in good hands.