Explore key facets of centrifugal pump ownership, installation, operation, and troubleshooting

The Second Edition of Pump Wisdom: Essential Centrifugal Pump Knowledge for Operators and Specialists delivers a concise explanation of how pumps function, the design specifications that must be considered before purchasing a pump, and current best practices in lubrication and mechanical seals.

This new edition also contains new startup and surveillance tips for pump operators, as well as repair versus replacement or upgrade considerations for maintenance decision-makers, new condition monitoring guidance for centrifugal pumps, and expanded coverage of operator best practices.

Read Chapter 2: Pump Selection and Industry Standards here.

Epoxy pre-filled base plates

As of about 2000, Best Practices Companies (BPCs) have increasingly used “monolithic” (all-in-one, epoxy pre-filled) steel base plates in sizes approaching 1.5 m x 2.5 m (about 5 ft x 8 ft). Larger sizes become cumbersome due to heavy weight.

In the size range up to about 1.5 m x 2.5 m, conventional grouting procedures, although briefly mentioned earlier in this book, are being phased out in favor of base plates pre-filled with an epoxy resin or grout (Chapter 3, Ref. 3). These pre-filled steel base plates then represent a solid block (the “monolith”) that will never twist and never get out-of-alignment.

The process includes five successive stages, all done under controlled conditions before shipment to the site:

1. Base plate fabrication. (No pour holes are needed for pre-filled base plates)
2. Stress relieving
3. Pre-grouting (primer application) in preparation for pre-filling. (If there are large pour holes, the inverted base plate must be placed on a sheet of plywood.)
4. Fill with epoxy grout and allow it to bond and cure
5. Invert and machine the mounting pads to be flat; then verify flatness before shipment (Fig. 3.8). Protect and ship (Fig. 3.9)–possibly even with pump, coupling and driver mounted and final-aligned.

Fig. 3.8: Flatness and level measurements determine if the now machined pre-filled baseplate has been properly machined. It is then ready to be installed on a foundation at site (Source: Stay-Tru®, Houston, Texas)

Fig. 3.9: Epoxy pre-filled base plate fully manufactured by a specialty company, shown ready for shipment (Source: Stay-Tru® Company, Houston, TX)

The advantage of pre-filling is notable. Jobs with pumps in the 750 kW (1,000 hp) category and total assemblies weighing over 12,000 kg (24,600 lbs) have been done without difficulty on many occasions. A conventionally grouted base plate requires at least two pours, plus locating and repair-filling of voids after the grout has cured. Pre-filled or pre-grouted base plates travel better and arrive at the site flat and aligned, just as they left the factory. Their structural integrity is better because they do not require grout holes. Their installed cost is less and their long-term reliability is greatly improved.

Chapter 3, Reference 3: Bloch, Heinz P. and A. R. Budris; “Pump User’s Handbook: Life Extension,” 3rd Edition (Fairmont Press, ISBN 0-88173-627-9)