Pumping untreated sewage presents a formidable challenge to sewage pumps, while operating within such an environment poses significant hazards for the involved operators. The process of choosing the optimal sewage pump mandates meticulous deliberation and analysis.
In the realm of Sewage pumps, an array of extraneous objects including cans, bottles, rags, saturated wipes, hair, and other entwining elements poses a formidable quandary. Within this operational context, numerous hazards loom for operators. These encompass laboring at elevated altitudes, performing tasks above water surfaces, handling substantial pendulous loads, and orchestrating intricate crane maneuvers, among a plethora of others.
When in the process of choosing an optimal sewage pump, there exist crucial considerations that demand your attention. These factors encompass vital aspects like the required gallons per minute, the total dynamic head, and the essential voltage specifications of the pump’s motor tailored to your specific application.
Within the confines of this article, we shall delve into the significance that high-head sewage pumps bring to the forefront.
High Head Sewage Pumps
There are several reasons a high head sewage pumps might be needed. Hilly terrains, long rising mains, small diameter rising mains, or an application could have a combination of these conditions.
Some of these “restrictions” may lead designers to consider using positive displacement pumps, adding a sewage pump station enroute to the treatment plant, or combining a submersible pump with a “pressure” sewage pump to deliver the required head. All of these options come with compromise. Positive displacement pumps are often not ideal for solids handling and running dry can be problematic, while putting pumps is series can add to capital costs to house the additional stages.
With these applications in mind, Gorman-Rupp developed the first 2-stage sewage pump they call the VS series, the high head version of their “Ultra V Series”. These pumps have a “regular” self-priming pump as their first stage, which pumps through a transition piece to the second stage, which is known as the “ultra-mate”. The result is so that sewage pumps can deliver heads to 95 metres and beyond.
The Ultra V and VS Series pumps deliver more than just pressure. They are packed with features that make them the easiest sewage pump to service and maintain:
- The self-priming “stage” can provide static suction lifts to 7.6 metres.
- Operators can adjust internal clearances of the sewage pump in minutes, without opening the pump and without disconnection the pump from the pipe system, allowing peak efficiencies to be maintained for the life of the pump.
- Seal and bearing oil levels and clarity can be inspected in seconds.
- Internal check valves can be inspected and/or replaced without having to drain pump casings and without having to disconnect the suction line.
- Major overhauls are even easy, because the complete rotating assembly can be removed as a cartridge by removing just four bolts.
- A lightweight inspection cover-plate on the sewage pumps allow operators to inspect pump internals or remove debris in minutes.
- The cover-plate and rotating assemblies are designed with “pusher-bolts” to enable operators to easily remove these components for inspection and/or service.
Solids Handling
The Ultra VS Series pumps can handle a 76mm spherical solid, but can also be fitted with Gorman-Rupp’s “Eradicator Solids Management System”, which enables the pumps to handle stringy materials such as rags, matted hair, gloves and wet wipes.
The eradicator system “attacks” stringy materials holistically:
- An aggressive self-cleaning wear plate incorporating a number of notches and grooves to help stop stringy solids from wrapping around the impeller, and to help break some of them up.
- A lacerating tooth on the wear plate protrudes into the eye of the impeller to continually scrape solids from impeller vanes before they can accumulate.
- A re-designed obstruction-free cover-plate won’t let stringy material gather.
Even Higher Heads
Because of the high-pressure rating of the “Ultra-Mate” [2nd stage of the VS pump], these can be used as 3rd or even 4th stages to reach heads as high as 160 metres. This feature gives designers the potential of cutting out the need for “half-way” pump stations, potentially delivering large capital cost savings.
Flow Rates
The “Ultra V Series” is available in three sizes. A 100 x 80, a 150 x 100 and a 200 x 150. The largest of these capable of delivering flows to 100 litres per second, and offers a hydraulic efficiency of 70%.
