Hyper Compressor Tungsten Carbide Plunger Repair

Solid Tungsten carbide plungers are the primary choice for hyper compressors for manufacturing Low Density Polyethylene (LDPE.) However, tungsten carbide plungers in this severe service is susceptible to premature failures and/or short runs due to gas leakage from the running combinations of lubrication, packing and plunger surface. Thermal fatigue (heat checking), fretting, corrosion and scoring are common problems found on the plunger surface resulting in premature leakage or even plunger breakage. This paper elaborates on these plunger problems, repairs and possible reasons for these surface defects.