Many factors, including design and terrain, affect the efficiency and lifespan of any pumping system.
For the West Coast of the United States, most residents face issues from catastrophic heat waves and droughts that plague one of the region’s biggest industries: agriculture.
It is said that California accounts for almost half of the country’s fresh produce and crops, with approximately 50 billion in products per year through the state and another 50 billion in ancillary products, according to the Orange County Register and The Washington Post. California clearly depends on agriculture, which means the risks and consequences that come with being in a semi-arid desert environment only grow greater.
When Water Is Scarce
Farmland is decimated at every turn. Fruit groves turn into dry, brittle wood piles while farmers abandon their land as once fertile soil becomes acres of desert. In cities, the fear of biohazards inch ever closer with the water supply dwindling. Public service announcements encouraged citizens daily to work harder to conserve.
Still, about 30 dams and reservoirs have been emptied or drained, reaching almost 100 billion gallons of water lost, per www.Archive.org. Add in the additional losses to economic movement from wasted potential labor, livelihood and the estimated losses in the industry at minimum is within hundreds of millions, with the predicted worst-case scenario one in the billions, says the Los Angeles Times.
Though occasional rainfall helps, the state is still lacking water resources. State officials estimate that 80 percent of all water resources are used for agriculture, per The Washington Post. So, groundwater inevitably plays an important role. Devising ways to bring water to the community from rivers, valleys and reservoirs becomes tantamount to survival.
Agricultural pumps are also seldom considered as one of the main runners of the pump industry. California’s industry means that counties’ pumps posed a special exception to the norm when it came to management, repair and replacement.
How the Pumps Failed
In fact, a major county in central California found itself in a crisis when its irrigation pumps were not even producing a foot of head, cutting off the critical water supply to the reservoirs and aqueducts. During this time, the county had to borrow water from the adjacent municipality. Between high vibrations during startups, metal on metal grinding and repeated failures, the entire pumping station was down.
The county reached out to the original equipment manufacturer (OEM) who extended their abilities as far as they could. However, the station operators noticed the same problems occurring repeatedly. A county inspector who had a strong background in pump engineering, Kent Kreeger, came out to inspect the issue. After a thorough inspection, he decided the pumps needed a full engineering study.
One aftermarket pump rebuilder has experience with similar issues previously and was able to analyze, deduce and quickly find a working solution. Knowing how critical the role would be, a field service team was mobilized with the full knowledge that time was of the essence, but quality and a meticulous analysis was to be the forefront of their work. The team soon realized after careful consideration and strict observation of how the pumps and the system worked that the issues started from one end, only to result in almost catastrophic effects on the others.
Vibrations, Systems & the Damage
Vibration is considered to be one of the main factors that play a role in how pump efficiency works. Depending on the frequency of the vibration and how it works in tandem with other factors (which may include pump design, environment of the system itself, the metal used, etc.), it is common for end users to see a decline in efficiency and reliability of the pump. It is also likely that end users see an increase in costs due to repairs and energy needed to continue wielding problems. As such, vibration is one of the many banes of the pump industry.
The county in California was one of the many whose pumps fell into the category of needing repair due to vibration issues. An aftermarket pump rebuilder’s analysis and study of the pumps showed that there was a great amount of vibration that led to overall damage.
The bearings were destroyed during operation, which severely damaged the shaft, bushings, vanes and propellers—meaning that the county’s longest lasting pump ran only to about 1,400 hours.
The components had been severely damaged due to friction. There was an alarming clearance of 1 inch between the propeller’s vanes and the column interior.
In addition, engineers found the rotor parts were “whipping” due to deflection at its own internal pressure, which was off center. The overhung rotor had resonance with the running speed, causing the additional damage.
All of these issues affected one another, from the damage to the pump’s parts to the sediments gathering at the nose from faulty protection to create the issues in efficiency.
The Plan of Action: Implementing Engineering & Repair
With these factors in mind, the aftermarket pump rebuilder’s team of engineers worked together to find a solution that would not only meet the requirements and expectations of the end user but also go above and beyond it.
Due to the pump’s sheer size, deflection was one of the larger issues. After sketches and analysis were done, the first solution proposed focused on supporting the pump properly. This was done through splitting the central column in half, creating two sides. The two sides were then inverted, and a new retainer bearing in the center was added.
Another action that was taken was to take away the channel ring and redesign the pump out vanes. Doing so would mean the pump would have better lubrication and flow to the bushings. The final set of solutions were designed to fix the issue of foreign objects entering the pumps, which would later cause damages to the rotor parts, including bent propeller vanes. Since the county was mostly relying on open suction pumps that used the intake of the bay, the aftermarket pump rebuilder recommended a combination of strainers and suppressors.
However, knowing that cleaning and deepening of the pumps might be scheduled, this recommendation was put to the side for a different solution. The team of engineers instead recommended redesigning the protection rings, which would help keep sediments out of the propeller and aids in keeping overall dynamic balance.
The solutions were reliable, effective and most importantly efficient for the end user. While the issues were due to a variety of factors—discharge deflection, the pump’s shaft experiencing whipping effects and extreme damage to parts that lead to self-destruction—the solutions employed took into consideration any possible concerns the end user had, such as future scheduling of pump cleaning, and worked with them to ensure the lifespan of the pumps could potentially be pushed further than ever before.