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In this latest case study, North Ridge Pumps are
talking about a project they worked on recently with a construction and engineering services company.
They were planning to build a sewage lift station which would need four high volume sewage transfer pumps to move sewage & sludge water with a density of around 1400kg/m³. The pumps would be designed to fit within a dry well inside a large chamber fed from an adjacent tank.
This wasn’t a project taking place in a remote, inhospitable location, or a large-scale industrial environment packed with heavy machinery. The four new pumps they would supply and the sewage lift station they were going into would be a key element in a multi-million-pound luxury new-build development taking shape in Iraq.
The project would consist of a collection of high-rise towers covering an area of some 165,000 m² and incorporating 3,000 luxurious, ultra-modern two, three and four-bedroom apartments.
"On every project, we strive to deliver products that perform at the highest level. On this project, achieving that standard was especially critical."
What is a sewage water lifting station?
A sewage water lifting station, also known as a lift station or sewage pumping station, is a facility that moves wastewater to a higher elevation when gravity flow alone isn’t sufficient. The station collects sewage in an underground wet well, and when the wastewater reaches a designated level, pumps automatically activate to force flow through a pipe to a higher point in the network, often toward a treatment plant.
How does it work?
1. Collection – the wastewater from residential, commercial or industrial areas flows into an underground collection tank called a wet well
2. Monitoring – built-in sensors in the wet well constantly monitor the wastewater level. These can be Float switches containing a magnetic contact switch which activates at certain liquid levels, ultrasonic level controls or probes.
3. Pumping – when the wastewater reaches a certain height, pumps turn on automatically to reduce the level in the chamber
4. Discharge - the pumps force the wastewater into a pipe that carries it up to a higher level or other point within a sewage network
5. Gravity flow – at the higher elevation, the wastewater then flows thanks to gravity to its destination which is usually a wastewater treatment plant
What type of pump is most used to handle wastewater?
Wastewater comes in different forms, and the right pump depends on the type. Sewage comes from homes and communities and includes water from toilets, sinks, and washing machines.
Industrial wastewater comes from factories and may contain chemicals and other pollutants. Agricultural wastewater includes water contaminated with animal waste, fertilizers, and crop run-off. Stormwater is rainwater that runs off roads, roofs, and other surfaces, often carrying dirt and debris into the system.
Handling it safely requires robust, reliable pumps that can tackle everything from solids to corrosive fluids. When considering pump selection, it is paramount that any pump technology chosen ensures efficient, durable, and safe wastewater transfer, protecting both your infrastructure and the environment.
Choosing the right pump for this application can be complex, and requires weighing several important factors to identify the most appropriate solution
Pump Location & Type
When it comes to sewage & wastewater transfer there are usually 3 choices - to have the pumps Immersed or submerged within a pit, Surface Mount units and prime liquid from tanks or have the pumps below or adjacent to a tank, meaning they are flooded with fluid.
If pumps are surface mounted in such installations, they will need to be self-priming. This means they are designed to evacuate air from the suction line and prime fluid. There are a variety of pump designs which are self-priming as standard such as progressing cavity, peristaltic, and AODD pumps. Other designs such as centrifugal must be specified at design stage as such.
The installation type can affect the amount of civil work required. Having a pump which is surface mounted or installed adjacent or below a tank can involve a bigger initial outlay in pump installation, however long-term maintenance costs can be reduced. Similarly having a pump head submerged within a tank, but the motor located outside the fluid will reduce maintenance intervals but require a crane for removal adding to servicing costs...
Thought also needs to be given to space available which can eliminate surface mounted pumps as options in particular when wastewater from car parks or other areas requires pumping as often the only space available is the chamber itself.
Maintenance
Careful consideration also must be given to maintaining pumps over their lifespan as both installation type and the pump technology chosen will impact the time taken to maintain units and how easy they are to maintain.
Submersible pumps typically involve the lowest investment cost but are very difficult to maintain effectively. If the liquid being pump is particularly corrosive, they can be troublesome when attempting to reseal after maintenance work on either the motor or cable gland – both frequent sources of water ingress.
Furthermore, if corrosion is present on sealing faces, sometimes the only way to obtain a good seal is to machine or replace the corroded parts to guarantee the seal will perform – potentially adding to maintenance woes. Confined space training and access control can also be required in certain installations meaning the number of people required to undertake maintenance quickly multiplies.
Immersed pumps can require removal via a crane for maintenance to be performed, and often the easiest types of pumps to maintain and service are those which are surface mounted.
Vertical inline and Long coupled means maintenance can be undertaken whilst pumps are in situ without removal of motor. It also means that should the chamber become flooded the pump motor is located high and as far out of reach as possible from the fluid. Over time potentially leaks can occur on valves, or seals making this a worthwhile consideration for pump protection. We recommended adding a liquid detector and small submersible pump as a safeguard in case the chamber floods.
Pump Control
Pumps in such applications can be controlled in a variety of ways. Operation can be automatic via float switches, level probes, ultrasonic switches, or manually which is only suitable for intermittent use.
Submersible pumps are often supplied with an integrated float switch for control, but other pump technologies can be operated via float switch for automatic operation if wired back into a control panel. Utilising a separate panel for pump control allows other functions to be incorporated into operations such as pump protection against dry running, or alarms for warning of pump blockage or stoppage.
Flow and pressure can then be regulated using pressure transducers in the discharge pipework, ensuring the pump empties the chamber as designed. Dry-run protection is provided through current monitoring or temperature probes to prevent damage.
Overall using a pump with a control panel is a far more industrial option for a process.
Our Solution
For this prestigious but demanding overseas residential application, we specified four of our XVIL high flow vertical inline centrifugal pumps.
Fitted with a spacer coupling for easy maintenance, this pump can be used for a wide range of applications in the industrial and marine sectors.
Engineered for endurance and continuous use, the heavy-duty bearing bracket absorbs radial forces through dual bearings - one in the pump head and one in the motor - ensuring reliable, long-term performance.
The centrifugal pump and motor have independent shafts. This means that only the pump shaft needs to be replaced if it breaks.
Each of these four heavy-duty vertical inline pumps is designed to transfer 180 L/s (650 m³/h), giving a combined capacity of 720 L/s (2,600 m³/h) of sewage. Featuring 10″ (250 mm) ports and AISI-316 stainless steel impeller, each pump is powered by a 132-kW motor, maintaining pressures between 3 and 4 bar.
Delivered as a completely new installation, we supplied the units with three non-invasive electromagnetic flowmeters ensuring accuracy of 99% across the pumps’ flow range.
We also incorporated a 162kw control panel with 5 multi-contact float switches with high level alarm. These would automatically start additional pumps as demanded by the sewage level but also stop the pumps at low levels.The customer installed these four high flow vertical inline centrifugal pumps on a concrete plinth for several important engineering and maintenance reason
Stable, level surface
The plinth provides a flat, steady surface for proper pump installation and alignment. This enables it to operate correctly and efficiently, preventing strain on the suction and discharge lines that might be caused by an uneven base.
Improved maintenance and access
The plinth raises the pumps up to a more accessible height for maintenance and inspection. It also gives plenty of room for lifting equipment such as a davit, to remove the pumps safely and easily when needed.
Vibration and noise reduction
The concrete plinth is a sturdy base that absorbs the torque and vibrations generated by the pumps’ operation. This limits excessive vibration and noise, optimising the pumps’ performance and preventing any damage to the surrounding structure or pipework.
Protection from debris and sediment
Moving the pumps higher means that the intake isn’t at the bottom of the wet well, where heavy
grit, sediment and general waste can build up. These can easily clog the pump impellers and intakes, which must be kept clear in critical wastewater applications.
At North Ridge Pumps we have over 25 years of experience, we’re not limited to just one type of pump either. We use our specialist knowledge and in-depth experience to develop the right solution for every client.
If you have a project which requires dewatering or simply want a high volume transfer pump in an easy to maintain, low maintenance, reliable unit, speak to North Ridge Pumps to see how we can help.
For more information on High Volume Sewage Transfer Pumps for Sewage Lifting Station talk to North Ridge Pumps Ltd