Pierce HUSKY 12 GPM, Operation & Maintenance Manual

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OPERATION
3-8 / Husky 12 Foam System
© 2017 Pierce Manufacturing Inc. All Rights Reserved.
3-4. Filling Foam Tank
NOTE: For the purposes of this manual, it is assumed that Class A foam is the most commonly used agent
and that the system will be stored wet with Class A foam concentrate. If Class A foam is not the
primary agent, adjust procedures to accommodate the primary foam concentrate.
3-4.1 Fill Dome Method
NOTE: Locate and close all foam tank and manifold drains. They may be found on and behind both the
driver and passenger side pump panels.
When filling the foam concentrate during a non-fire situation, the following procedure is recommended:
1. The vehicle should be parked on a level surface or with the expansion dome of the tank slightly inclined.
2. If filling from a pressurized source through the expansion dome hatch, the hose should be extended to the
bottom of the tank to minimize frothing of the foam concentrate.
3. If foam concentrate must be added by pouring through the expansion dome hatch, it must be done slowly to
prevent aeration. If aeration occurs inside the tank, stop pouring until the foam concentrate bubbles dissolve.
Take care not to allow dirt or debris to enter the tank. Pour the foam concentrate down the center of the round
tube when filling the tank. This tube goes into the tank and allows the foam concentrate to enter under the
surface of foam currently in the tank to reduce aeration of the foam per NFPA.
Do not mix different types or manufacturer’s brands of foam concentrate in the foam cells or piping.
Mixing of different foam concentrates (either type or manufacturer) may cause deterioration of the
foam concentrate, improper proportioning, and poor performance in a fire situation. Mixing of Class A
and Class B foam concentrates may result in a chemical reaction that can create globules, which can
clog orifices and cause system failure.
Do not mix different types or manufacturers brands of foam concentrate in the foam cells or piping.
Mixing of different foam concentrates (either type or manufacturer) may cause deterioration of the
foam concentrate, improper proportioning and poor performance in a fire situation. Mixing of Class A
and Class B foam concentrates may result in a chemical reaction that can create globules, which can
clog orifices and cause system failure.