The Impact of Journal Bearing Wear on an Electric Submersible Pump in Two-Phase and Three-Phase Flow

Electric submersible pumps (ESPs) provide artificial lift within oil wells. ESPs commonly fail from mechanical vibrations that increase as bearing clearances increase from debris, gas, and liquid pumped through the ESP. In order to understand journal bearing wear within an ESP, three stages of a mixed flow electric submersible pump were subjected to hydraulic fracture sand slurry in water. One hundred seventeen hours were conducted with sand and water, followed by 68 h with air added at 15% inlet gas volume fraction. The journal bearings were severely worn by the end of testing, and pump vibrations increased with increased bearing clearances. Bearing vibrations and clearances became significantly larger than the impeller labyrinth seal vibrations and clearances, indicating that the labyrinth seals became the dominant rotor support once the bearings were worn. Adding air increased the wear and rotor vibration orbit variability. Rotor vibration orbits were entirely independent of gas void fraction by the end of testing, indicating that the lubricant composition no longer directly impacted vibrations. Fine axial cracks from heat checking were observed on the journal of the bearings. Results indicate that controlling journal bearing wear is a critical factor for increasing operating lifetimes. Alternative bearing geometry and materials should be investigated to prevent the occurrence of three-body abrasion, limit the resultant wear rate from three-body abrasion, and limit the damage from heat checking.

BÖHLER W303 ISODISC

Böhler (or Boehler) W303 ISODISC is a hot work tool steel with outstanding hot tensile properties, high retention of hardness, good toughness, and resistance to heat checking. W303 ISODISC is a special grade with improved homogeneity and increased toughness. This datasheet provides information on composition, physical properties, and elasticity. It also includes information on forming and heat treating. Filing Code: TS-724. Producer or source: Böhler Edelstahl GmbH.

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.

An Investigation of the Melt-Out and Heat Checking Phenomena in Surface Modified Hot Die Steel for Aluminum Die Casting

For hot die steel, failure is mostly caused by heat checking and melt-out on its surfaces which are in contact with molten metals. In the present research, resistances to melt-out and heat checking of surface modified H13 hot die steels, such as gas nitriding(GN) and micro-blasting(MB), were investigated. The evaluation of melt-out behavior was carried out by measuring the mean depth from the original surface after immersion. To examine the thermal fatigue resistance, a cyclic thermal shock system consisting of induction heating and water spray quenching was constructed. The value of Lm is proposed as the index representing the susceptibility to crack initiation and propagation. The melt-out depth was the lowest for the GN treated surface. MB-GN and MB-GN-MB treated specimens also showed good resistance to melt-out. In the case of GN treatment, while the white layer was completely melted out, the diffusion layer still existed even after immersion for 43 hours. This implies that nitriding significantly reduced the rate of melt-out. From the total crack number, it is seen that crack initiation was reduced to the extent of half after surface treatment. This result means that the residual compressive stress and nitrided layer were beneficial to crack initiation resistance.

Development of Multi-Layered and Graded Die Coatings for Materials Processing Applications

The paper will present the methodology used to design optimized die coatings employed in material forming processes in an effort to extend the life and effect efficient operation of the dies. An optimized die coating 'architecture' requires that the coating system be essentially non-wetting with the material (metal, glass, polymer) being formed in the die, coupled with good wear and oxidation resistance Other factors, such as delaying the onset of thermal fatigue cracking (heat checking), and an acceptably low coefficient of friction. And, possibly, self-lubricating, also need to be considered based on the processing and forming conditions that include both liquid and solid materials. Many different die coatings have and are being used with different levels of success. This paper presents the current understanding that has been gained in laboratory testing, in-plant trials, and modeling in an effort to generate a fundamental understanding of how such optimized die coating systems may be designed for specific forming operations and conditions, with examples based on dies used in aluminum pressure die casting, glass molding, and metal forming operations.