Six Foam Transfer Pumps Delivering Reliability in Critical Fire Suppression

In this latest case study, we explore the vital role of foam transfer pumps within fire suppression systems, following a client request for a set of reliable and proven foam concentrate transfer pumps to operate at the core of their fire protection infrastructure.

Fire remains a constant risk to industrial operations, particularly across sectors handling volatile substances or operating in hazardous environments. Facilities within oil and gas, chemical processing and manufacturing must manage this risk daily, where even a minor ignition event can escalate rapidly.

Despite stringent safety procedures and robust fire prevention strategies, incidents can still occur. When they do, the consequences can be catastrophic, with the potential for severe asset damage, operational downtime and risk to life.

Fire extinguishing systems as a critical safeguard

When primary fire prevention measures fail, automated fire suppression systems become the last line of defence. These systems are essential in containing and extinguishing fires quickly, limiting escalation and protecting both personnel and infrastructure.

Firefighting foam plays a central role in this process. It is formed from a premixed solution of water and foam concentrate combined with air to create a dense and stable blanket.

Once deployed, this foam spreads across the fuel surface and adheres effectively, creating a barrier between the fuel and oxygen. By sealing flammable vapours, it prevents reignition and suppresses the fire at its source.

In addition to smothering the fire, foam provides a cooling effect that reduces the temperature of the burning material. This dual action enables it to tackle both Class A fires involving solid materials and Class B fires involving flammable liquids.

Four key mechanisms work together during foam application. These include separating fuel from oxygen, suppressing vapours and smoke, cooling the fuel surface and containing the fire to prevent further spread.

How firefighting foam systems operate

Synthetic firefighting foam concentrates are typically stored in dedicated tanks before being delivered to a proportioner. At this stage, the concentrate is accurately mixed with water to achieve the correct ratio for effective fire suppression.

The foam solution is then transported through a network of pipework to discharge points such as spray heads, foam generators, pourers or monitors. These components direct the foam precisely to the hazard area, ensuring rapid and controlled extinguishing performance.

An important consideration in system design is the rheological behaviour of foam concentrates. Their viscosity varies depending on temperature and they exhibit shear-thinning characteristics. This means that as pump speed increases, the fluid becomes less viscous.

For example, at approximately 30 rpm the viscosity may reach around 500 cps, while increasing the speed to 60 rpm can reduce viscosity to approximately 250 cps. This behaviour must be accounted for when selecting pumps to ensure consistent and reliable flow.

To accommodate different fire risks, foam systems may use low, medium or high-expansion foam. Each requires tailored pump solutions to ensure optimal performance under varying operating conditions.

The pump solution for this application

To meet the client’s requirements, six HGP external helical gear pumps were specified. These pumps are widely used for handling viscous fluids at controlled speeds, making them well suited to foam concentrate transfer.

The design incorporates two interlocking gears positioned within the pump head. One gear is driven by the motor while the other rotates in response, enabling the smooth displacement of fluid through the system.

With only two primary rotating components, this simple yet robust construction delivers high efficiency and exceptional reliability. This is particularly important in fire suppression applications where system failure is not an option.

As an additional safety measure, the pumps were supplied with ATEX explosion-proof motors. ATEX refers to European Union regulations governing equipment used in potentially explosive atmospheres. Compliance ensures safe operation in environments such as oil refineries, chemical plants and other hazardous industrial settings.

Detailed pump specification and performance

The six HGP external helical gear pumps were engineered to transfer foam concentrate at flow rates ranging from 10 to 35 cubic metres per hour at a pressure of 12 bar.

As positive displacement pumps, they deliver a consistent flow regardless of system demand, ensuring that pressure at the discharge points remains stable. This is critical for maintaining effective foam distribution during a fire event.

Each pump was designed as a long-coupled and baseplate-mounted unit, incorporating a gearbox to reduce pump head speed. This configuration allows sufficient time for high-viscosity fluids to enter the pump and ensures the gear teeth can maintain consistent flow without cavitation or performance loss.

The pumps were paired with a 30 kW four-pole 1500 rpm motor, with the gearbox reducing operating speed at the pump head to approximately 450 rpm. This careful speed control is essential for handling shear-sensitive fluids such as foam concentrates.

Featuring DN65 flanged connections, the pumps integrate seamlessly into industrial pipework systems. Their stainless steel construction provides excellent corrosion resistance, ensuring long-term durability even when handling aggressive or variable-viscosity fluids.

Supporting reliable fire protection in UK industry

For UK industries operating in high-risk environments, investing in reliable fire suppression infrastructure is essential. Foam transfer pumps play a critical role in ensuring that firefighting systems respond instantly and effectively when needed.

By combining robust pump design, precise flow control and compliance with ATEX safety standards, this solution delivers dependable performance in demanding conditions.

For applications requiring smooth and consistent foam concentrate transfer, North Ridge Pumps can provide tailored solutions designed to meet specific operational and safety requirements.