What is foam eductor?

An eductor is a device that uses the Venturi principle to introduce foam concentrate into the water stream. Water coming in the inlet of the eductor is directed through a tapered section and out through a small orifice (the Venturi) into a larger chamber thus creating a low pressure area within the chamber.

What do you pump foam eductor with?

Pump Pressures & Percentages Eductors are typically pumped with a 200-psi inlet pressure. This is due to the high friction loss, roughly 30 percent, through the small Venturi area. The pick-up tube can be placed in a foam bucket or attached to a foam tank supply.

What is a foam proportioner?

Firefighting foam proportioners are used to mix water and firefighting foam concentrate with air to produce low, medium or high expansion fire fighting foam. A foam proportioner can be used with all types of fire foam concentrates from 0.3% to 6%.

How far should a foam eductor be from the nozzle?

A 125 gpm eductor has a slightly larger smoothbore, and 350 gpm eductor has an inlet nozzle slightly less than one inch (0.90”). Using the 65% rule, distance from a 95 gpm eductor to a foam nozzle is a function of the back pressure. Fire ground hydraulics dictates that a 95 gpm foam stream will flow through 200 ft.

What is Afff made of?

Aqueous film forming foams (AFFF) are water-based and frequently contain hydrocarbon-based surfactant such as sodium alkyl sulfate, and fluorosurfactant, such as fluorotelomers, perfluorooctanoic acid (PFOA), or perfluorooctanesulfonic acid (PFOS).

What is an around the pump proportioner?

Around-The-Pump Proportioning Systems provide a simple and effective means to introduce a foam concentrate at the desired percentage to the water being discharged in a fire pump system. The number of different foam concentrates is only limited by available space as each concentrate requires a separate tank.

What is a proportioner?

Definition of proportioner : one that proportions : a device for securing proportions in a mixture pumping liquid foam through a proportioner and smothering the fire in the gasoline hatch— K. M. Dodson.

What is the correct operating pressure for an in line foam eductor?

The inlet pressure of the eductor varies with the manufacturer, but most operate at an inlet pressure of 200 PSI.

How does AFFF work?

When applied to a hazard, AFFF produces an aqueous film that spreads across the surface of the fire to extinguish the flame. This film is what gives AFFF its name, and it works by suppressing flammable liquid vapor, effectively suffocating the fire hazard.

Does AFFF foam expire?

When stored in the packaging supplied (polyethylene drums or pails) or in equipment recommended by the manufacturer as part of the foam system and within the temperature limits specified, the shelf life of ANSULITE ARC 3% or 6% AR-AFFF Concentrate is about 20-25 years.