Exclusive: The benefits of hydraulically driven submersible pumps


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Leaning on 33 years’ experience in mobile water transport, Hytrans Systems explains the benefits of hydraulically driven submersible pumps

Hytrans® has developed, manufactured and supplied mobile water transport units with hydraulically driven submersible pumps (HydroSub®) since 1988. During these 33 years Hytrans has supplied almost 1200 HydroSub® units across the globe. Quality, proven performance and innovation are the keywords that contributed to the success of the mobile water transport equipment of Hytrans®.

The biggest advantages of using the hydraulically driven submersible pumps versus the conventional suction pump is the vertical pump lift without draft loss and the deployment time. With a conventional system there is a suction line in place, and the needed priming consumes valuable time, especially when time is at a premium. In addition, when drafting from 7 meters down the pump capacity reduces by 70%. 


By using the Hytrans® hydraulically driven submersible pumps, this is not a problem anymore because the hydraulically driven pump is floating, priming is not needed and as a major advantage there is no draft loss. This means pumping water from 60 meters vertically down to any (open) water source can be achieved easily.  

As Hytrans® strives to supply their customers with mobile and easy to handle water transport systems, they have chosen to build these systems onto containerised modules. With this, each container can be handled by means of a truck with a hook arm lift off system. In case of a large-scale incident, systems can be combined as complementary modules to increase capacity and pumping distance with a minimum time and manpower. When all this is combined, it makes for the perfect tool for situations where water is a key commodity. 

A versatile solution 

Hytrans® supplies complete mobile water transport solutions over long distances for municipal Fire and Rescue services as well as for the Industrial Fire Service and Nuclear Power Plants. The HydroSub® high volume pump units have a capacity from 1.500 lpm @ 10 bar (approx. 400 GPM @ 150 psi) up to 45.000 lpm @ 12 bar (approx. 12.000 GPM @ 175 psi) and are part of the standard products range. 

The HydroSub® units are not only deployed to provide fire water for large scale incidents but also to reduce the aftermath of large-scale floods and supplying cooling water in emergency situations for nuclear power plants. For example, in 2012 Hurricane Sandy ripped through the city of New York, resulting in floods. HydroSub® units were used to pump the flood water from the Holland tunnel. 

Hytrans® equipment also had a significant role during the Fukushima incident in 2011, and even more recently HydroSub® units have been deployed all over Australia to supply firefighters with water in difficult circumstances to fight the ongoing bushfires that are becoming more common every year in the region. 

The FloodModule 

Because of climate change, flooding is becoming more prevalent all over the world. In anticipation of this, Hytrans® developed an add-on system for flood fighting for the HydroSub® 150 unit, called the FloodModule. This module is equipped with specially designed flood pumps which can replace the standard submersible pump. With this add-on system the capacity of the HydroSub® unit is multiplied by 6 to achieve a capacity of 50.000 lpm (13.200 GPM). Based on this success other models of the HydroSub® range can be equipped with flood pumps and new development has made the pump lighter and therefore even more easy to deploy.  

The HydroSub® high volume pump units are an important part of the system but it is not the only item that needs attention when considering a complete mobile water transport solution. The Hytrans® Hose Layer Containers including Hose Recovery Units are designed to deploy and recover hoses including the coupling up to 12”-diameter. 


These large diameter hoses will have a recovery time of only 45 minutes for a length of 1.000 metre (12”). Recently, Hytrans® introduced a fully automatic hose recovery system called the AutoFlaker. With this system one can recover up to 12”-diameter hoses without the need of manpower. The only manpower needed is the truck driver, who can control the system from his or her cabin. Making the system easy to deploy and recover will encourage people to use it and train with it, so they will be prepared when it really matters. 

Fast deployment  

Fast deployment is key in emergency situations. For the deployment of large diameter hoses, it is important that couplings can withstand ground impact. A low weight on the coupling reduces the force of the impact but also increases the length of hose that can be stored inside the Hose Layer Container, because of the decrease in size of the coupling. Therefore Hytrans® supplies HFS/AWG Multi Lug couplings as a standard for the hoses, these are PN16 rated but also low weight and have a high impact resistance.  

To make the connections within the mobile water transport as well as the connection to fire trucks or monitors, Hytrans® has a range of light weight portable water supply equipment. It gives you the ability to make the connections to set-up a complete temporary above ground hydrant network in minutes. Die casted aluminium Y-Pieces that can be manhandled, non-return valves, gate valves etc. are available as a standard up to 12” in diameter, but Hytrans® is also able to manufacture special hardware.  

An important element for a high-volume water transport system remains the choice of material for large diameter hoses, with the basic options being rubber or polyurethane. The main difference between these two materials is heat resistance. PU is not recommended for firefighting because it is unable to withstand the effect of a burning object, as per BS 6391 (Hot Cube Test). Therefore, the hoses that Hytrans® supplies are made of through the weave extruded rubber. Several factors should be considered when equipping your water transport system with the right large diameter hoses. These include working pressure, burst pressure, wear resistance, weight, elongation/expansion ratio, and hose recovery. 

When having to use large diameter hoses, one needs to make sure that the hoses are flexible, heat resistant and have limited elongation. Due to the use of special fibres, the elongation of the Hytrans® hoses are less than 1,5% at working pressure. Tests have proven that hoses with more than 1,5% elongation will move a lot or even “jump” when pressurised.   

The importance of accuracy 

As the benefits of a complete mobile water transport solution become recognised, the systems become widely used for firefighting. Because of this it was necessary to develop a foam injection unit that is very accurate and can deal with high flows that are needed to extinguish the largest (petro-chemicals) fires. This resulted in the Hytrans® PowerFoam option which can either be integrated in the larger HydroSub® units or supplied as a standalone unit.

The latter can be placed at any point in the water line. Due to the hydraulic driven foam gear pump and the accurate monitored water flow, the exact amount of foam concentrate is added to the water flow. Foam setting can be done from 0-6% with increments of 0,1%. The system works in such a way that it is fully independent from pressure and water flow and adapts automatically if there is fluctuation. Accurate foam mixing is the result. It also features a return line which allows you to return the foam concentrate back to the container during training sessions. The whole foam setting on the unit as well as the foam logistics can be trained without using precious foam. 

The system works in such a way that it is fully independent from pressure and water flow and adapts automatically if there is fluctuation.

To complement the mobile water transport systems, Hytrans® has a range of trailer mounted monitors up to a capacity of 60.000 lpm. These monitors can be equipped with a nozzle that has a variable flow adjustment which allows you to change the flow setting at work pressure and without interruption of operation. The trailers are designed in such a way that there is no need for a water ballast tank.

Monitors above the 20.000 lpm are mounted on a trailer that has an extremely reduced overall height so the wheel axle can be lowered by means of an integrated mechanical operated hydraulic pump. The gears that move the monitor are self-arresting and completely covered, sealed and greased for complete lifecycle. The monitor bodies are made of an aluminium alloy and the inside is optimised to get superior performance. For every specific need Hytrans® can supply the right type of nozzle, such as jet, jet/spray and nozzles with foam attachments. 

The mobile systems made by Hytrans Systems are a complete solution and designed to be used in extreme circumstances. In these circumstances the system must be deployed in minutes using minimum manpower. Therefore the engineers at Hytrans® are constantly working on making things easier, lighter and with a higher performance without affecting performance. Mobile high-volume pumping will always be a constant development to get bigger, better, faster and lighter equipment to help fire fighters to fulfil their job. We are using our 33-years of experience to make the best system worldwide available.  

This article was originally published in the latest edition of International Fire and Safety Journal

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