New FM certificate for higher viscosity values of foam proportioners

Recently, the FireDos foam proportioners with high-viscosity foam concentrates were again subjected to FM tests – with convincing results: The optimized proportioning systems have shown that they can also admix foam agents with even higher viscosities than the previous models. They therefore achieve FM-approved viscosity values for so called ‘Variable Viscosity Foam Proportioners’ that are unique on the market.

A proportioner classified as a “Variable Viscosity Foam Proportioner” is a device that can be used to accurately admix foam concentrate to water for any viscosity below the tested viscosity values. In practice, this means that the proportioner can handle both low viscosity (Newtonian) and high viscosity, pseudoplastic foam agents within the tested flow rates and back pressures to produce premix at a constant proportioning rate.

According to the latest FM test results, the viscosity values of the FireDos foam proportioners not only significantly exceed those of the previous models, but also those of the FM-certified competitor products within the “Variable Viscosity Foam Proportioner” group. On average, the certified viscosity is 12% higher. (as of December 2024)

When using high-viscosity foam concentrates, the pressure loss of many proportioning technologies is significantly higher than with low-viscosity foam concentrates. It is therefore all the more remarkable that, according to the FM test results, FireDos proportioners have only a low pressure loss at maximum extinguishing water flow. 

The electromagnetic flow meter for measuring the foam agent volume flow is also FM-certified. Installed on the return line, it reliably measures the extinguishing agent flow and enables the proportioning rate to be determined. According to FM, a general estimate of the extinguishing water volume flow in the range of 20 % to 100 % of the maximum flow rate can be made with the optional, calibrated tachometer.