Courtesy Fire Chief Magazine.
Eductor Education
The most common tech support questions concern setting up for foam-eductor operations. For those who are having trouble making foam with the industry’s default proportioning device, there is help available.
First, alcohol-resistant foam is supposed to be gel-like in appearance. The thicker it is, the more alcohol resistant it is. Eductors will work fine with AR-AFFFs. Most UL-listed AR foams use foam eductors.
Let’s bust another myth: AFFF and AR-AFFF have no specific shelf life. Twenty-year-old foam is fine as long as the foam has been stored according to package instructions on its package. The secret is keeping containers airtight. Foam concentrate will evaporate if containers are left open or with lids ajar.
Placing an eductor somewhere in a hose-line is a pain in the neck. Try to keep the eductor attached to a pump discharge. The eductor is much better off at the pump, where the operator has light, communications, pressure gauges and a ready foam supply. A 1I-inch hose will handle 3% (97 parts water and 3 parts foam concentrate) or 6% 200 feet from the engine. Two-inch hose on a 95-gpm eductor will work 400 feet from the engine. (See “Foam-Eductor Distance in Feet at Level Ground” on page 80.)
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