Comparison of a bladder tank installation vs. a FireDos proportioning solution

For many fire threats companies worldwide are relying on foam as extinguishing media. For the past decades companies have been using conventional foam proportioning systems such as bladder tanks with a wide range proportioner or driven gear pumps with wide range proportioners, where excess foam agent is returned to the foam agent tank. In 1994 the company of FireDos developed and introduced the first proportioning system based on the concept consisting of a water motor, driven by the fire-fighting water, and a coupled piston pump.

The main advantages of using a water motor driven piston pump proportioner are: 

• The system is purely mechanical – no electric power is required
• The proportioning rate does not have to be calibrated as there is a fixed mechanical correlation between water flow and foam concentrate flow
• The proportioning rate is constant over a wide range of flows and back pressures and not effected by turning various output devices on and off intermittently – there are no electronics that must adjust to new parameters
• The FireDos GEN III water motor driven proportioning systems exclusively use in house designed piston pumps that are engineered and tested for use with both low viscous Newtonian and high viscous pseudoplastic foam agents – no recalibration is necessary when switching concentrates 
• All systems are equipped with foam agent return lines for cost-effective and eco-friendly testing of the proportioning rate without having to produce premix or foam
• As the separate foam agent tank is unpressurised and can therefore be refilled whenever necessary, users benefit from unlimited fire-fighting time 
• Thanks to the wide operating range, the proportioning systems are qualified for all types of fire extinguishing systems like sprinkler, deluge, foam chambers, fire monitors, wet and dry extinguishing systems
• The system offers a compact and versatile installation

No matter the industry or fire brigade, to date more than 15 000 FireDos proportioners are installed successfully worldwide.

Several years ago, our exclusive Egyptian partner SBS Projects and Technology participated in an upgrade project for the storage facility of a local oil company. In consistence with its business plan, HSE commitment and social responsibility, the operator started a project to upgrade its fire & gas detection and fire-fighting systems based on the latest PSM (Process Safety Management) standards & guidelines. The scope of work was to include a new fire & gas detection and fire-fighting system including fire water pumps, foam proportioning systems and remote operated monitors. Offered Solutions are fully integrated detection and fire-fighting systems with highest industry safety level SIL 3 control systems to manage automatic detection and fire-fighting using FireDos’ proportioners and remote operated monitors.

To date the operator had been using ILBPP (In-Line-Balanced-Pressure-Proportioning) Systems for foam generation and distribution. Due to the size of the installation this system was complex with numerous pipes running to the various parts of the facility. In Egypt SBS Projects and Technology is recognized as a value differentiator. This means that they approach projects with a focus on new design techniques, mainly for EPC’s who have a vision and full control over the project CAPEX & OPEX budget, preferably using FM approved components. These shall be engineered and designed to optimize the performance of the system while considering a setup that will have the lowest possible total cost of operation in mind. Hereby the SBS scope will include a detailed engineering design, the supply of all components as well as the installation of the system, ending with the transfer of a guaranteed working system that can be maintained by the reliable SBS service team.

The foam proportioning solution offered by SBS, that was installed in 2022 and 2023, to safely upgrade the old systems, used the new and reliable water motor driven piston pumps, designed and built by FireDos. 

The project required a total of 20 foam discharge points, that had to be independently fed with premix. Even though the proportioning rate was the same for all discharge points, the flow volumes, and distances from the proportioners, which are equivalent to differing pressure drops, varied. Using the former ILBPP technology, a total of 20 In-Line-Balanced-Pressure-Proportioners, each equipped with an own control valve, were needed. The ILBPP’s were fed with foam concentrate by a diesel-electric foam proportioning pump. In this project the total cost would have amounted to approx. USD 1,400,000. The FireDos solution using three skid-mounted FD10000 proportioning systems of the latest generation, GEN III, resulted in a total cost of approx. USD 970,000. Apart from the reduction in cost the two additional advantages that were seen was the reduction in necessary ground space as well as the considerable reduction in maintenance cost. With the FireDos proportioner you have the ability to test the proportioning rate of the foam, without having to create foam or premix, by using a return line. This way you do not have to consume any foam concentrate or refill your atmospheric foam storage tanks. In addition you do not have to dispose of any foam or premix, which helps in your ecological balance sheet.

Beside the savings in the foam proportioning and valve systems, the significant reduction in pipework resulted in a cost saving of approx. USD 555,000. In addition, the project construction time could be reduced by six months. A comparison of images 2 and 3 makes this difference very obvious.

In addition to having used FireDos proportioning systems, SBS re-evaluated the fire monitor extinguishing concept for the two storage tanks and dyke areas. To date 8 monitors witj a maximum water flow of 2,000 lpm with mechanical self-oscillating devices were used, each with their own local foam concentrate tank, proportioning system and deluge valve skid. SBS changed the system to a more innovative design, using only 2 slightly bigger FM approved FireDos M5 monitors. These fire monitors were equipped with remote controlled volume adjustment nozzles (AMPN-nozzle). They have a longer throwing range compared to competitor products. This is due to the innovative octagonal design that was engineered using hydrodynamic computer-modelling, that resulted in a lower pressure drop. This reduction in pressure drop allows for a bigger throwing distance that can cover the complete area to be protected with a maximum water flow of 12,000 lpm at 8 bar pressure at the inlet of the monitor base. By moving to this concept, an additional approx. USD 400,000 could be saved. 

As a last recommendation the move to a new flame-detections system, designed by the company of FGD, using IR3 and optionally HD cameras was integrated. The system is programmed by SBS to allow the fire monitors to either automatically extinguish in a predefined area, using remote controls with FM approved programmable SIL 3  logic controllers, or manually. 

Overall, by using innovative approaches and out of the box solution recommendations, SBS, could help the operator save about 15% on the complete project budget, compared to the original design. Beside saving on cost, the operator can now rely on state-of-the-art technology.

FireDos specializes in the development and production of innovative and reliable proportioning systems and extinguishing monitors for fire-fighting. FireDos provides its customers security – through risk reduction, lower operating costs and compliance with legal regulations. Every single FireDos product is designed, built, and tested to meet the most challenging conditions. The proportioning systems and extinguishing monitors fulfill an elementary task: they protect people, buildings, plants and equipment.

All foam agent types, even those of high viscosity, can be mixed. A constant proportioning rate across a wide operating range guarantees automatic adaptation to variable firefighting scenarios. Another advantage: The cost-effective and eco-friendly proportioning rate testing method works completely without producing foam or premix. 

This article has originally been published in Gulf Fire, April 2024.