Repair Standard for Vertical Pumps


Written by:
Dr. Lev Nelik, Pumping Machinery, LLC
Published:
January 20, 2012

Since the original publication of this draft standard in the January 2008 issue of Pumps & Systems, I have received feedback, encouragement, numerous questions and criticism. The draft listed three basic levels of repair:

Level 1: Basic repair

Level 2: Extended repair

Level 3: Complete overhaul

Each adds increasingly extensive machining work and cost. While most of the comments strongly encouraged a need for such a standard, many wondered how a specific level (1, 2 or 3) can be prescribed and quoted before the pump is pulled, reassembled and examined at the shop. 

Determine the Need for Repair

Commercial considerations and the logistics of the quotation process further complicate this issue. With vertical pumps, a need for a repair is usually determined by the plant operating and maintenance personnel and is based on increased vibrations. Most of the vertical pump body is below the soleplate, making assessing the pump’s condition difficult. 

Spectral vibration analysis can reveal some potential problems—a bent shaft, worn bushings, etc. However, practically speaking, the extent of the repair cannot be determined without the pump being removed and examined. The dilemma for a repair shop is what level of repair to quote?

Example

One example involves mid-size, single-stage vertical pump. Assume that a Level 1 repair costs $20,000, including pulling the pump, cleaning/blasting, replacing a few bushings, reassembling, painting and other standard maintenance and repair. A Level 2 repair might cost $50,000, and a Level 3 repair it might be $120,000. Obviously, the cost of each level will also depend on the pump length, metallurgy, number of stages and other factors. 

If the pump had already been removed and repair shops were asked to inspect it and provide competing quotes, then the quotation process would be simple and straightforward. The quoted numbers, provided by several (usually at least three) repair shops, would be relatively close: $20,000 (Shop A), $22,000 (Shop B) and $24,000 (Shop C). In this case, Shop A with the lowest quote would get the job (assuming that all three bidders are technically capable and qualified to handle the repairs). The problem is, however, that the pump had not been removed. This makes the quotation process more difficult. The repair shops are now faced with the dilemma of which level to quote? 

One Quote

Shop A assumes that the repair will be completed at a minimum extent and quotes $20,000 (Level 1). Shop B assumes an extended repair and quotes $50,000 (Level 2). To do things right, Shop C decides that a full restoration of fits, clearances, the replacement of worn rings and other measures will be needed and quotes $120,000 (Level 3). 

The purchasing department of the plant will likely award the job to the lowest bidder (Shop A). Once shop A pulls the pump, reassembles and examines it, its personnel may discover that the extent of damage is actually at a Level 2 requirement ($50,000). However, the committed quote of $20,000 prevents them from conducting that level of work. 

Presenting a new quote to the pump owner would seem reasonable, but with shops B and C by now out of the picture, such an approach may, in the long run, raise the eyebrows of purchasing.

Three Quotes

Requesting to prepare three different quotes based on each level also presents a dilemma. For example:

           Level 1   Level 2    Level 3

Shop A $20,000 $50,000 $120,000

Shop B $22,000 $52,000 $122,000

Shop C $10,000 $100,000 $300,000

What would be the basis for the purchasing decision? If awarding the job based on the Basic Level ($10,000) but afterward having to pay $300,000 for the full repair (by which time the award is made), then plant would end up paying almost three times more compared to what the other two shops would have charged.

Only Quote for Level Three

Because of such dilemma, there are two main approached taken by the plants when soliciting the quotations. The first is to specify the full blown overhaul (Level 3), which guarantees the pump will be done “perfectly” and, as rightly hoped, last a long time, - but knowingly paying more regardless if the inspection confirms the need to such full repair (repair shop making modest profit), or just a minor damage – in which case a repair shop makes very good profit. 

Only Quote Simple Work

The second strategy is to specify just a bare bone work (clean/blast, change bushings, reassemble and paint), with any additional work to be found during inspection to be quoted then – allowing the repair shop charge a very high premium, as it is usually not practical to shop the reassembled pump to another shop for a new quotation of the extended repair need.

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See also:

Upstream Pumping Solutions

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