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.

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Throwback: Expedited Vertical Pump Repair & Engineered Upgrade

A critical vertical pump for a 750 MW unit was sent to Hydro South in mid-December 2012 for inspection and repair. The massive pump weighed more than 66,000 lbs. and was 32 feet long and 12 feet tall. When the pump was disassembled, Hydro South’s engineers discovered that a large 42” x 68” section of the discharge elbow was broken, allowing direct flow to bypass the turning section and flow directly into the stuffing box area.

The discharge elbow was made of casted cast iron and could not be welded. A replacement of this size would take around eight months to order and receive. Continue reading

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State of the Art Parts: Expedited Impeller

The destroyed sample used for reverse engineering

State of the Art Parts: A Gulf Coast refinery had the primary pump for a critical system at the HydroTex Golden Triangle facility for refurbishment. While the primary pump was in the shop, the backup pump operating on-site began to show signs of failure. The impeller of the pump being repaired had extreme wear and was unable to be reused. The shop needed to source an impeller in an expedited timeframe to complete the repair ahead of schedule and get the primary pump back in service before the backup pump failed. Continue reading