- Case Study Summaries
- UAN Solution Pumps
- Horizontal Mulistage Pump (BB3)
The Root of Reliability
The Hydro Companies provide a range of pump repair, engineering, and support services to the Fertilizer Industry. Through engineering expertise, Hydro keeps pumps operating at maximum efficiency for better performance and longer life.
Click on any of the links to the left to learn more about our experience in improving the performance and reliability of your critical pumps.
New Pumps with Vibration Issues are Redesigned for Reliable Operation
A recently constructed fertilizer plant was experiencing significant vibration problems on their brand new UAN Solution pumps. This vibration forced the plant to take the equipment out of service. The site was unable to diagnose the root cause of this problem on their own and the unreliability and resulting unavailability of this critical equipment was causing significant stress on the new plant. The pump was shipped to one of Hydro’s repair shops. The following were completed:
- A thorough disassembly, cleaning, and inspection (DCI).
- A review of the original pump design and historical vibration information provided by the plant.
- A Root Cause Analysis (RCA) that explained the aberrant behavior of the problem pumps such as incorrect designs on the motor coupling, bores running against the lineshaft couplings, and excessive manufacturing tolerances and clearances.
- Re-engineering of the pumps to eliminate the diagnosed problem and provide the plant with reliable operation.
The redesign required modifications to approximately 70% of the pump. With one pump removed for service, the site was forced to operate with only one pump. As such, these modifications needed to be completed on an emergency schedule. Fortunately, Hydro had the resources to perform this repair on the required schedule of 2-3 weeks, allowing this piece of critical equipment to return to service. The new pump design has resulted in successful operation since installation and start-up in late 2017.
Re-Engineering System Reliability
A US fertilizer plant was experiencing recurring reliability problems and failures with their horizontal multistage boiler feed pumps.
They completed the following:
- A Failure Modes and Effects Analysis (FMEA) that placed into consideration the historical failure information and included an independent engineering analysis of the operating conditions.
- A disassembly and inspection on the next degraded pump to validate the probable root cause.
- A modification to the impellers which allowed the plant to meet the system demand using one pump while also providing other significant benefits to the plant.
A review of the system history uncovered that the fertilizer plant had originally been designed with two 100% pumps. When the system was uprated, increased output requirements necessitated that both pumps operate in parallel to meet the new demand. Based on this information, the FMEA determined that the most probable failure mechanism was discharge recirculation caused by low flow operation.
The final modification (underfiling) to the impellers resulted in only requiring the operation of one pump to meet system needs; this allows the site to have an installed spare. Another benefit of optimizing pump operation for the single pump is a reduction in the horsepower required to provide the system flow. This optimization fits into the drive to improve energy efficiency and reduce the overall cost of operating the plant.