Repair to HD vertical pumps [split]

[HVoilF]

Hello T/S colleagues,

we do need to repair HD vertical pumps(1200HP). The fluid being pumped is a salt water slurry mixed with heavy oil and sand so the abrasion is an important technical factor to be considered. The OEM pump has duplex(stainless) shafts and carbon bearing and obviously the pump must be serviced every 4 to 6 months to replace the weared bearing and the shafts. So our doubt is ,if in this working condition, being the bearing water cooled and lubricated ,could we manufacture stainless steel bearings and coat them in it I.D. with HVOF Wc Co Cr as well as the shaft in the bearing working area,resulting in a mating Wc/Wc pair bearing-shaft without any adhesion (galling) between the sprayed Wc coating. Would it work? Is it a good mating pair the Wc against Wc material? Any suggestion is welcome. Thanks

[Gordon]

Hi HVoilF

Looking back at some old data from Union carbide (Ucar) now Praxair. Dry rubbing test LW-1 vs LW-1 (WC/9Co) and LW-1N30 vs LW-1n30 (WC/13Co) D-Gun coatings were rated at good to excellent. So it may be worth a try, but as with all of these things it really needs testing within your specific application.