The Hidden Costs of Cheap Repairs

Posted on April 23, 2025

Why Technical Expertise plays a Critical Role in Equipment Maintenance

As the industrial world becomes more competitive, reducing costs is key for maintaining an advantage in the marketplace. As such, many end users have become more cost-conscious when approaching equipment repair. In some services- where equipment is not complex and performance doesn’t affect process availability or quality- this strategy can provide some benefit. However, the short-term gain of a lower repair price often turns into long-term cost increases when a lack of engineering capability impacts equipment reliability and performance.

The importance of engaging with a facility that has strong engineering capabilities and subject matter expertise was proven during a series of boiler feed pump repairs for a Canadian biomass power plant. Like many biomass facilities, this plant had segmental ring boiler feed pumps, also commonly referred to as BB4 pumps. This is a complex design installed in a high energy, critical application, with numerous stacked and nested components that must be kept in alignment.

In this case, a small shop had completed several repairs that had resulted in high vibration and performance issues. These pumps were a legacy design that was no longer supported by the OEM and required engineering knowledge to properly refurbish and set the balance device. As such, it was important to find a repair partner that had a strong understanding of pump design. The plant worked with Hydro’s Scotford facility to bring these “bad actor” pumps back to optimal performance.

Read the full case study in World Pumps‘ March/April 2025 edition here.

Navigating Resonance Challenges

Posted on March 22, 2024

A Case Study in Diagnostic Testing and Innovative Solutions

Some services are inherently difficult due to factors such as fluid quality or multiple disparate operating points. These factors are an inherent part of the process and cannot be changed to improve reliability. Harsh applications can be a costly prospect, both in overhaul costs and in the time and labor required for frequent servicing. Many times we become caught in the perception that there is no improvement to be had for these services. A short mean-time-between-failures (MTBF) becomes routine and expected, and maintenance activities and parts procurement are built around this expectation.

When equipment is sent out for refurbishment, the expectation is that mechanical and hydraulic performance upon reinstallation will be better than what was experienced in the worn condition. This assumption holds true in most cases; however, sometimes unexpected behavior can occur after a pump is remanufactured and reinstalled. While it is easy to jump to the conclusion that these performance changes were caused by errors made during the repair or installation of the equipment, sometimes the problem is more complex and related to latent weaknesses in the design that had lain dormant until refurbishment.

This scenario was experienced by a power utility in the Southeastern US when they ran into significant vibration increases after one of their boiler feed pumps was refurbished by a local repair shop. Concerned by the level of vibration, the utility reached out to Hydro South, who have extensive experience in this application and model. From there, Hydro Reliability Services was called on to collect data on the problematic equipment and use advanced modeling tools to understand the nature of the vibration. The field testing and analysis revealed that pump had been operating with a very small margin between a structural resonance and one of the pump forcing frequencies. Armed with this information, solutions were developed to increase this margin and return to stable operation.

Read the full case study in Pumps & Systems March 2024 edition.

Learn more about Hydro Reliability Services and how they support field testing, vibration troubleshooting, and advanced system studies.

Engineering a Long-Term Solution

Posted on December 23, 2019

Figure 1. The pump as received

Many pumps in operation today were designed and manufactured decades ago. As plants require increased capacity, pump systems are expected to meet these higher process flow demands. Without an impeller rerate or change in speed, this increased capacity can be achieved in one of two ways. The individual pumps can supply more flow to the system, resulting in operation out on the pump curve. Alternatively, capacity can be increased by operating more pumps in parallel; in this case operation is pushed back on the curve, as operating another pump in parallel requires less flow from each individual pump to meet total system demand.

Either operational change results in a move away from the pump best efficiency point (BEP). As a result, the original designs and hydraulic characteristics no longer effectively meet plant requirements and detrimental effects from hydraulic instability can occur.

By way of example, this article will discuss a fertilizer plant in the Gulf of Mexico that had a boiler feedwater pump unit that was experiencing performance problems after a significant plant expansion project. Unfortunately, it was not the first time this particular unit had experienced a loss of capacity; the pump had been in operation only 18 months prior to the current issue.