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Fully Equipped & On the Move

Hydro was called on to reverse engineer a large circulating water pump in the Caribbean to supply parts for refurbishment. The lead times for receiving parts from the original equipment manufacturer (OEM) were excessive. More concerning, the suction bell provided by the OEM had failed during service. All internal ribs were lost, and the bearing holder was found loose within the assembly.

When Hydro reviewed the design of the suction bell, it was clear that low manufacturing cost was prioritized over reliability. Instead of providing a cast component, the suction bell was fabricated and had an excessively thin wall thickness.

Hydro reverse engineered the suction bell and created a model for a cast component, establishing the rib design and bearing holder location based on design experience. Exterior ribs were added to strengthen the bell and the wall thickness at the suction bell skirt was increased from 3/8” to 2”. The part was scanned on-site within 1 day, with the engineering analysis, modified casting design, and quote for manufacture being
completed within about 3 weeks.


Optimum Flow – Expert Solutions When It’s Critical

A major county in California found itself in a crisis when its irrigation pumps could not produce the required performance, cutting off critical water supply to the reservoirs and aqueducts. These pumps suffered from high vibration and repeated failures characterized by extreme wear to the propellers, shafts, and bearings.

The OEM had extended their abilities as far as they could but were unable to resolve the problems. Hydro’s engineering team was called on to provide a failure analysis and design an effective solution. Hydro found that deflection induced by high radial forces, excitation of the rotor critical speed at running speed, and faulty protection from sediment all contributed to the failures.

Evans Hydro redesigned the bearing span to counteract the deflection and critical speed issues. The pump-out vanes were also redesigned to provide better lubricating flow to the guide bearings. Finally, the protection rings were redesigned to keep sediment from the propeller and provide better overall dynamic balance.

The solution provided by Hydro significantly increased the life of the pump. Not only were the changes effective, but they were executed efficiently. The modifications were completed in an expedited time frame, allowing the county to resume reliable water service to the agricultural industry that depends on it.


Circulating Water Pump Repair & Refurbishment

A major utility company had a Foster Wheeler 60 DF horizontal split case circulating water pump that required repair. They decided to complete the refurbishment during a 14-day unit outage by using the Hydro South service center. The plant had a spare impeller, shaft, and shaft sleeves in inventory. The availability of spare parts usually facilitates an efficient and trouble-free repair. Unfortunately, it was discovered that the parts available were not properly designed for use in the existing pump.

Before the pump was pulled for the outage, the spare parts were sent to the Hydro South facility for inspection. This is where the first problem was discovered- the threaded shaft and shaft sleeves were designed for the incorrect rotation. If they had been installed as-is, the rotation of the pump would have resulted in displacement of the sleeves. The plant elected to modify the parts to prevent the sleeves from backing off during operation. Hydro South accomplished this by drilling and tapping the sleeves for set screws and dimpling the shaft.

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Pump Testing Overcomes Challenging Suction Configuration

A municipal water treatment plant recently had one of their service water pumps refurbished. The refurbished pump is a single-stage, bottom suction BB1 (between bearing) pump with a double suction impeller. In order to validate the performance of the pump, the plant requested testing services from the Hydro Performance Test Lab. The testing services included a Hydraulic Institute certified performance test, a Net Positive Suction Head (NPSH) test, and a bearing housing vibration test.

The bottom suction design of the pump provided some challenges in the design of the test layout and in conducting the NPSH test. The bottom suction design of the pump did not allow for the typical piping layout design. Instead, the mounting feet of the pump needed to be elevated and supported at least 5 feet from the floor to correctly connect to the suction manifold. Changing the pump mounting elevation meant that the motor also needed to be elevated and supported at the same height. Continue reading

State of the Art Parts: Impeller with New Hydraulic Design

State of the Art Parts: Hydro Parts Solutions recently supplied a new impeller as part of a project to improve the operation of a pump that was not performing per the OEM curve. The first step in the process was reverse-engineering the used sample impellers. The reverse-engineered model was used by Hydro’s Global Engineering team to perform a computational fluid dynamics (CFD) analysis to determine the best possible hydraulic design for the plant’s expected operating range.

Once the impeller redesign was completed by the Hydro engineering team and accepted by the site, Hydro Parts Solutions cast 12 impellers out of ductile iron. After the casting was inspected and approved, the impellers were machined at the Hydro Parts Solutions machine shop in Tomball, TX.

Despite the extensive scope of work, Hydro’s Global Engineering and Parts Solutions teams were able to perform the reverse engineering, CFD, hydraulic redesign, and part manufacture within six and a half weeks. This work was completed as a routine delivery for our customer. This project highlights the extensive capabilities Hydro has in-house that streamline engineered projects and provide our customers with a superior product in a lead time that exceeds the industry standard.