Beware the Cheap Fix: You May Get What You Pay For

Fossil plant required an emergency rebuild when poor quality repair caused a holiday shutdown. 

Written by: Dr. Gary Dyson & Mohamed Mohamed
Published by: Pumps & Systems

The consequences of poor quality repairs can result in premature failure, unplanned outages and higher repair costs because follow up after the initial attempt is considered an emergency repair. That was the situation when a major fossil plant experienced an emergency failure of a six-stage, boiler feed pump element. It was a quiet holiday night when the pump had to be pulled due to lack of flow, causing a plant shutdown. Unfortunately, when the plant tried to set the spare element up on bearings, employees were unable to turn the rotor. In this case, the emergency occurred when the repaired spare element had to be used immediately after initial failure. Thus, the problems with the previous repairs were uncovered.

Because it was the holiday season, the plant’s usual service provider could not respond in the required time. Another Hydro was called in to assess the problem, engineer a solution and save the plant thousands of dollars in downtime.

Field service was mobilized to provide labor in two 24-hour shifts.

Worthington element

Image 1. Worthington element set on precision v-blocks, checking vertical and horizontal clearances at the suction end and discharge end. These checks are used to see if element is concentric.

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Emergency Nuclear Pump Rebuild

Faisal Salman and Nick Dagres of Hydro, Inc report how performing new design modifications on two critical safety-related charging pumps have extended their lifespan and reduced maintenance.

Written by: Faisal Salman & Nick Dagres
Published by: World Pumps

Certified Test Lab

Setting up the pump at Hydro’s Hydraulic Institute Certified Test Lab.

A Western European nuclear power plant was having difficulty meeting the necessary hydraulic performance at runout for two centrifugal charging pumps. The system needed 30 ft of Net Positive Suction Head required (NPSHr).

The pumps are safety-related pumps, which pump bore-rated water (water mixed with boric acid) into the reactor to kill nuclear fission. What water is to fire, bore-rated water is to nuclear fission. Bore-rated water kills nuclear reaction.

The two pumps are each about 15 ins in diameter and about 100 ins in length. They were shipped from the Western European site to Hydro, Inc.’s Chicago, IL facility to conduct analysis, redesign, manufacturing, and testing.

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