Case Studies

Headbox Feed Casing Refurbishment

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Application: Headbox Feed
Pump Details: Single-stage Sulzer ZPP 800
Pump Type: Double-suction Horizontal Split Case

After years of useful service, casings of many horizontal split case pumps are quite worn and no longer meet the original specifications. Hydro offers an alternative to purchasing a new OEM casing that offers a much lower cost and reduced turnaround time.

Due to their long-standing relationship with Hydro, a paper mill decided it was time to restore the casing of their headbox feed pump. Because this pump was in a critical application, the mill required a very short turnaround time.

To avoid a temporary shut down of the mill, Hydro was able to perform a line bore and insert upgrade within a period of three days. Utilizing around-the-clock shifts, Hydro completed the case inspection and developed machining fits and tolerances to restore the casing to its original specifications. Hydro then manufactured and mounted inserts to the casing.

Not only were the casing and wear components restored to their original fits, the upgraded materials will significantly improve mean-time-between-repair.

Learn more about Hydro’s targeted upgrades for the pulp and paper industry here.

State of the Art Parts- Rerated Impeller

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Hydro Parts Solutions recently manufactured three impellers for a rerate project being developed through Hydro’s Rocky Mountain service center in Denver, CO. Hydro Global Engineering determined the new hydraulic design for the rerated pump, which required modifications to the casing and new impellers.

 

The end user chose to have the new impellers manufactured out of CA6NM using investment casting, which provides a smoother surface finish to slightly increase the impeller efficiency. Hydro Parts Solutions drove the project from casting package design through final machining, with the impellers being cast and finish-machined within 6 weeks.

The new pump design was successfully tested at Hydro’s performance test lab, validating the new hydraulics. The custom performance will help the midstream end user achieve their desired system flow with maximum reliability and minimum energy usage.

Explore Hydro Parts Solutions’ design process in this video case study.

Hydraulic Rerate Proven in Performance Test Lab

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Custom Hydraulics for the Midstream Market

This summer, Hydro completed a hydraulic rerate project for a major US midstream pipeline. The project was completed through Hydro South, Hydro’s southeastern US service center in Alpharetta, Georgia. The project was completed with testing support from the Hydro Performance Test Lab, Hydro’s 5000 HP test facility located in Chicago, IL, with engineering direction from Hydro Global Engineering, based in Manchester, UK.

The pipeline originally used two booster pumps and the use of a Drag Reducing Agent (DRA) to achieve the desired flow rate. To increase the overall flow capacity of the line and remove the need for the DRA, the end user specified a pump to be added to the system downstream of the booster pumps.

The pump performance specifications were developed by system engineers and communicated to Hydro. The pump’s original design condition was modified to provide the necessary differential pressure required for the desired flow rate – for today and in the future. This will be achieved without the use of DRA or with little added to the system.

Hydro modified an existing pump casing provided by the pipeline and designed new impellers to meet the specific hydraulic performance requirements. Using computational fluid dynamics and advanced modeling, the new impellers were manufactured and installed by Hydro, then sent to Hydro’s test facility for hydraulic performance testing.

To provide an exact performance match, a larger impeller diameter size was selected for the first test and subsequently trimmed to meet performance within API 610 tolerances. Along with the hydraulic performance test, the mechanical integrity of the pump was measured with a vibration test, mechanical resonance test, and a bearing housing temperature stabilization test. All this information validates the quality of the rebuild and ensures a reliable machine.

The pipeline has a limited ‘budget’ of DRA concentration allowed pipeline wide. This concentration is measured in part per million (ppm). By adding the hydraulically rerated pump to the branch line, the DRA ppm budget can be allocated elsewhere in the pipeline. This will add efficiency and increase overall throughput.

Hydro is very fortunate to support critical industries like midstream pipelines in ensuring safe, reliable, and cost-effective pumps and rotating equipment.

Learn more about Hydro’s Performance Test Lab and Engineering Services

Challenging MTBF Expectations

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Improving Maintenance Intervals in Demanding Applications

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.  

It’s important that processes are built around historical run times to anticipate needs in the short term. However, it is equally important to take a step back and ask– “is this maintenance interval really acceptable or is there something that I can do to improve it?” An end user in the Canadian oil sands industry decided to take on that challenge when faced with a problematic bitumen froth transfer pump. This end user partnered with Hydro’s Scotford facility in Alberta to develop a series of upgrades that improved operating life while simultaneously reducing the cost of repair. 

Read the full case study in World Pumps July/August 2023 edition.

Learn more about our Hydro Scotford service center.

How do you measure axial thrust?

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Innovations in Thrust Measurement

Thrust is an important factor in vertical turbine pumps because it directly affects the performance and reliability of the pump. Excessive axial thrust can cause the motor thrust bearing to wear faster, run at a higher temperature, and/or fail if overloaded. This results in a higher total cost of ownership by reducing equipment operating life, forcing unexpected downtime, and requiring costly emergency work.

Historically, thrust has been a calculated value based on the impeller design and other pump parameters; this calculation is an approximation and has a margin of error. Axial thrust can be more accurately assessed through testing, but direct measurement of the thrust across the profile of a pump performance curve is not typically performed by OEMs.

In support of a customers’ request to better understand the repeated failure of a vertical turbine pump, Hydro’s Test Lab and S. Himmelstein and company developed a thrustmeter that provides users with an accurate and reliable measurement of thrust across the tested performance curve. This measurement was not only more accurate than the calculated thrust values, it provided insight beyond a single operating point.

By monitoring critical pump and motor data, the end user was empowered to make the best possible decision for their equipment and plant.

Read more about this innovation in our joint white paper, published with Pumps & Systems magazine.

Learn more about how Hydro’s Certified Performance Test Lab and how Hydro can support you in better understanding and optimizing the performance of your equipment.