Category Archives: Lomakin Effect

Save Money on Your Next BB3 Pump Overhaul

How to re-use the worn wear rings for better performance

Axially split, between bearings multi-stage pumps (API Type BB3) are used for some of the most important services in the hydrocarbon processing industry–charge pumps, boiler feed pumps, and product shipping/pipeline pumps.

The repair of these pumps is a great opportunity to upgrade with Vespel® CR-6100 or Boulden B-Series composite wear rings. In many situations, this will also be the most cost-effective way to rebuild the pump.

Cost of Repair
The reason these pumps offer a great value upgrade is because the case rings in axially split pumps can generally be re-used as holders for composite “inserts” as shown in figure 1.

This method of repair saves the cost of purchasing new case rings, or machining full rings with milled features. All of the work can be done on a lathe at the time of repair. First, you machine the inside bores of the existing case rings, throttle bushing, and center bushing. Then, you make the Vespel® CR-6100 inserts, press them in, and then final machine the parts to reduced clearance. This will increase the Lomakin Effect and efficiency of the pump.

Complete the remaining elements of the overhaul as you normally would. When the pump goes back into service, it should be easier to operate, more efficient, and more reliable.

Final Thoughts

If you have a BB3 pump coming through your shop for overhaul, consider upgrading to composite wear parts. Boulden can help you engineer the upgrade to Vespel® CR-6100 or Boulden B-Series and the patented Boulden PERF-Seal® design to ensure long-term reliable success. Contact us today. We have the material you need in stock.

Helpful Links:

Boulden Installation Guide for Vespel® CR-6100

Standard Stock Sizes of Vespel® CR-6100

Vespel® CR-6100 Product Data Sheet

Vespel® CR-6100 Machining Guide

2MW Boiler Feed Pump Case Study

Amine Stripping Pump Case Study

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