Six foam concentrate transfer pumps for critical fire suppression system
EDITOR’ S CHOICE FOAM PUMPS THAT DELIVER
NORTHRIDGE PUMPS
Six foam concentrate transfer pumps for critical fire suppression system
Our latest case study will be diving into the world of fire suppression where we received a request from a client for a set of reliable, proven foam concentrate transfer pumps to be used in the heart of their fire suppression system.
Clearly, fire is a constant threat to the operation of any company, particularly those handling volatile substances, or working in hazardous environments.
But even with the highest levels of fire awareness and prevention throughout the business, fires can and do break out – often with catastrophic and fatal consequences.
Fire extinguishing systems are the last resort
Firefighting foam is perfectly designed to suppress fire. It’ s made of a pre-mixed solution of water and foam concentrate mixed with air.
This thick substance forms a stable foam blanket which spreads out across the fuel and sticks to surfaces. The firefighting foam concentrate prevents fuel coming into contact with oxygen, effectively sealing in flammable vapours and preventing re-ignition.
It also has a strong cooling effect which lowers the fire temperature to extinguish both Class A( solids) and Class B( liquid) fires. Four key mechanisms work in conjunction to smother the fire from fuel and air, suppress vapours and smoke, cool the liquid and finally contain the fire.
We designed the pumps to be long-coupled and baseplate mounted using a gearbox to reduce the pump head speed.
The synthetic firefighting foam concentrates are supplied from a tank to a proportioner where it’ s mixed with water. This mixture is then transferred through pipes to spray heads, foam generators, pourers or monitors that direct it straight to the source of fire extinguishing it rapidly.
Firefighting foams vary in viscosity by temperature. They are also shear-thinning meaning that the faster they’ re pumped the thinner they become. At around 30 rpm the viscosity can be around 500cps, but when increased to 60 rpm the viscosity halves to 250cps.
What was our solution for this client?
The six HGP external helical gear pumps we supplied will transfer the firefighting foam concentrate at rates from 10 to 35m ³/ h at 12 bar. As they are positive displacement pumps, the same pressure will always be delivered to nozzles regardless of the amount of foam needed.
We designed the pumps to be longcoupled and baseplate mounted using a gearbox to reduce the pump head speed. This ensures that the high viscosity foam concentrate has time to enter the pump head, and more importantly, that the teeth within the external gear can maintain the flow.
We coupled the foam concentrate transfer pumps to a 30Kw four pole 1500rpm motor with the gearbox further reducing the pump head speed to around 450rpm. The pump head has DN65mm flanged connections.
Made from corrosion-resistant stainless steel, the pumps will transfer the foam concentrate whatever its viscosity at the flow rate required.
If you have an application requiring the smooth and consistent transfer of foam concentrate, get in touch with North Ridge Pumps to see how we can help.
For further information, please visit www. northridgepumps. com / contact-us
12 PECM Issue 80