Engineering Analysis Resolves Startup Issues at Middle Eastern Plant

During the commissioning and startup of an alumina processing plant in the Middle East, a significant recurring pump issue was causing delays to the commissioning of the facility. When de-energizing the equipment, the live steam condensate vertical can pumps experienced repeated failures of all installed units. These seizures occurred at both the design fluid temperature and when pumping cold water.

Because this was a new plant in the commissioning phase, the equipment was under warranty. However, negotiations with the OEM were lengthening the challenged startup schedule. There was little insight into the root cause of the equipment failure.

As the repeated failures were affecting the plant commissioning date, the large architect, engineering and construction (AEC) firm in charge of plant commissioning decided to contact an independent, aftermarket service provider located in Dubai, United Arab Emirates, to conduct an assessment to determine the root cause of the pump failures and provide solutions.

Read the full article at pumpsandsystems.com

Full Refurbishment for Island Refinery

After a refinery closed down its 50-year-old plant, most of the rotating equipment suffered damage from exposure to the tropical climate. To restart the plant, the new owners called upon Hydro, Inc. to reverse engineer, rebuild and perform testing on their critical jet pump.

The process of reopening the plant had uncovered more than 500 pumps that needed considerable refurbishment and repair. The most important of these was a critical jet pump used for hydraulic decoking.

It was badly damaged and sent to the original equipment manufacturer (OEM) for inspection. The OEM recommended that the refinery replace most of the pump parts, as well as a costly repair that would require 35 weeks to rebuild.

Instead, the refinery sent the pump to global aftermarket pump service provider, Hydro, Inc. in Chicago, where it was refurbished for just over half the cost of the OEM proposal.

Read the full article at worldpumps.com

The Dangers of Operating Pumps at Low Capacity

Operating at low flow places the machine under a great amount of duress. It is always wise to have a mental picture of what is happening within the passages of the machine to understand why this is the case.

The days have long passed where pump vibrations were viewed as a matter of mechanical balance. Now, we recognize that even if the pump had perfect mechanical balance, it would still exhibit vibrations.

The intensity of this remnant vibration turns out to be flow related with its minimum level being at or around best efficiency point (BEP).

Read the full column at pumpsandsystems.com

Wireless Condition Monitoring Optimizes MTBR

 

Alerts, advanced analysis, and automated reporting help to improve maintenance strategies and critical asset decision-making.

A power plant in Southeast Australia had recently experienced chronic high vibration amplitudes on a critical multistage boiler feed water pump. Given the criticality of the pump and the risks associated with catastrophic pump failure, the power plant contacted Hydro Australia for support.

In collaboration with Hydro, Inc.’s wireless condition monitoring team, Hydro Australia was able to provide the power plant with a significantly improved IIoT-based monitoring system. This would assist the plant by closely monitoring the status of its asset, making the best possible decisions for equipment maintenance, and ensuring equipment availability

Read the full column at pumpindustry.com.au

Engineering a Long-Term Solution

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.