Testing of Foam Systems

Foam systems are provided wherever there are large quantities of liquid hydrocarbons that pose a high risk. The primary concern with foam system performance is the proper production of foam and the time to provide adequate foam sealage coverage to the designated area. 

Foam systems are designed to proportion liquid foam concentrate in the foamwater distribution network at certain ratios usually expressed in percentages. The most common of these are 1%, 3%, and 6%. The foamwater can then be aspirated or non-aspirated to the appropriate liquid surface as the risk demands. The foam production should be verified it is being proportion in the ratio designed for the system otherwise foam consistency may be inadequate and foam supplies will be consumed at rates higher than expected. 

Coverage confirmation, time to provide full foam coverage, leaks, blockages, rupture disk function, age of foam, portioning calibration mechanisms, performance of delivery pumps or bladder tanks, foam drain times, etc. should be verified for each unique system. NFPA 11 provides guidance in the specific test requirements for several characterisitic foam systems. 

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