Submersible Sewer Pumps and HDPE Pipe Meet the Denver Sewer Bypass Challenge

In mid May 2005, Rain for Rent, Denver, was contacted to supply pumps for a bypass pumping project.  The contractor's initial concern was whether or not 12 inch diesel pumps and/or submersible sewage pumps were available.  Multiple 12 inch DV-300s and two 35 HP 8 inch submersible pumps were available at the Denver yard and more could be made available through networking with the other Rocky Mountain Rain for Rent branches.

After collecting all the necessary facts about the flow rate and job conditions, Rain for Rent personnel visited the project site to become more familiar with the location.  Rain for Rent met with several representatives of the contracting firm and their previous pump provider. 

Both the contractor and the pump provider were perplexed by the inability of the 12” pumps to handle the flow.  Rain for Rent personnel evaluated the situation, communicated with their engineering team and together they discovered multiple challenges. 

First, the elevation of the Mile High City makes lifting fluid 18 feet difficult for any centrifugal pump. 

Second, a single 12 inch line of SDR 17 was being used to transport the desired 9,000 plus gallons per minute.  To achieve this flow, the velocity would need to be around 20 ft/sec. 

Finally, the entire system had zero air vac/vent relief throughout. 

After a few days, the premature curing of the resin bag which was stored in a refrigerated truck for the sewer relining became a big concern.  Time was against all parties.  A Rain for Rent associate from the Bay Area assisted in air freighting an 88 HP 12 inch and a 35 HP 8 inch submersible pump from other Rain for Rent locations.  An 18 inch line was constructed and air/vac relief valves were strategically installed. 

The liner was saved and the contractor was convinced that Rain for Rent had the best expertise in designing a bypass system.  Four additional large bypasses were scheduled.

To date, Rain for Rent has supplied four DV-400 16 inch Power Prime™ pumps and numerous fittings, pipe and roadcrossings, bringing successful completion to two major bypasses.