OH2 Bearing seal & frame upgrade

[Woodlands]

many of the pump OEM's advertise upgrades to OH2 pumps in refinery and chemical applications to improve MTBR and as a way to install a low emmsions mechnical seal. They say that MTBR improves becasuse of lower shaft deflection (stiffer shaft) and maybe larger bearings, but I am wondering if anyone has seen or experienced using these upgrades and getting positive (or negative) results?

 

[JJPellin]

We have been installing back pull-out assemblies on older pumps for many years. We typically do this because the older pump has a seal chamber that cannot accomodate the seal design we need to install. Many of these old pumps were bell-housing designs which did not allow for the installation of a cartridge seal. In general, our reliability after these conversions was much, much better. The stiffer shaft and upgraded bearing designs probably have something to do with it. But mechanical seal reliability was the driving justification in most cases and the seal reliability improvement is the most dramatic effect.