UW Hospital Booster Stations

Project Highlights

In the fall of 2012, UW Health approached Municipal Well & Pump for repairs to one of their vertical turbine booster pumps, which boosts city pressure to the upper floors of the hospital. The damage to the pump was extensive, but we were able to repair it in under a week. Hospital staff had been told the repairs would take between 12 and 16 weeks by another supplier. The damage to the pump was considerable, and we had some concerns regarding the operation of the equipment. The hospital personnel indicated this was an ongoing problem that used up a lot of their manpower. The asked us to make a site visit to view the operation of the various pump skids to make recommendations for system improvements.

The existing pump skids were equipped with across-the-line starters and pressure reducing valves to limit the pressure produced by the pumps as they ran full speed. Each of the four pump skids had two pumps running continually to produce enough water for the intermittent draws on the system. The continuous pumping, at times against dead head, caused accelerated damage to the pumps and used excessive electricity at no real benefit compared to water needs. Additionally, the pressure reducing valves required constant repairs because they were in continuous use causing them to wear our prematurely. Furthermore, there were several different makes of equipment and pump designs, which meant they needed several spare pumps to assure continuous water to the facility.

Municipal Well & Pump determined the best approach would be to standardize the pumping equipment for the two cold water skids and the two hot water skids. The old across-the-line starters and pressure reducing valves were eliminated. New variable frequency drives (VFDs) were installed to operate the pumps based on pressure needs. In addition, the pumps were fitted with Vesconite bearings to prolong the pump service life. These bearings also made the equipment run much quieter. Once the new pump equipment was installed with the VFDs, we found that one pump per skid was all that was needed for nearly 90 percent of the operations. Rather than running two 20 HP pumps continuously to supply the lower cold water system, only one 15 HP pump was needed for a majority of the time, and most of the time it was running at half speed and consuming about 5 HP of power. These results were similar on each of the four pump skids. The electrical savings resulting from the new controls and pumping equipment is estimated at $7,500 per skid for an estimated total annual electrical savings of nearly $30,000 per year.

When the hospital decided to bring a new cold soft water line into the facility, the successful retrofitting of their existing pump skids led them to order a new three-pump skid with the same 15 HP pumping equipment as the other two cold water pump skids. The hot water skids are fitted with 10 HP pumping units, and the cold water skids are all fitted with 15 HP pumping units. Prior to the retrofits, there were 20 HP pumps, 10 HP pumps, 7 ½ HP pumps, and 5 HP pumps. This required an inordinate number of spare pumps and motors to keep on hand for spares. As it stands right now, the facility only needs a spare 15 HP pumping unit and a 10 HP pumping unit, which cleared their storage area and eliminated a substantial amount of money tied up in spare equipment.

Altogether the project dramatically reduced the electrical consumption for the water system, reduced spare equipment inventory, and freed up considerable hours that hospital personnel spent working on the pressure reducing valves and failed pumping equipment.

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