🧯 Inline Foam Inductor
An Inline Foam Inductor is a portable proportioning device installed directly into a fire hose line to mix foam concentrate with water at a fixed ratio (commonly 1%, 3%, or 6%).
It is widely used in manual firefighting operations where a simple, reliable method of producing firefighting foam is required without pumps or external power.
⚙️ Working Principle
The inline foam inductor operates using the Venturi effect:
Pressurized water enters the inductor body.
The Venturi throat creates a pressure drop inside the unit.
This pressure differential draws foam concentrate through a pickup tube from a foam container.
The concentrate mixes with the water stream to create a premixed foam solution.
The foam solution is discharged through a foam nozzle to generate finished foam.
This method ensures accurate foam proportioning when operated within its rated flow and pressure.
🧩 Main Components
Inlet Coupling – Connects to water supply hose
Venturi Mixing Chamber – Creates suction for concentrate induction
Metering Orifice – Controls proportioning percentage
Pickup Tube with Strainer – Draws foam concentrate
Calibration / Metering Valve – Selects 1%, 3%, or 6% (model dependent)
Outlet Connection – Sends foam solution to discharge hose and nozzle
📐 Typical Technical Data
| Parameter | Description |
|---|---|
| Proportioning Ratio | Fixed or selectable (1%, 3%, 6%) |
| Flow Rating | Designed for specific flow (e.g., 200, 400, 800 LPM) |
| Operating Pressure | Typically 5–10 bar (70–145 psi) |
| Material | Brass / Aluminum Bronze / Stainless Steel |
| Induction Method | Inline Venturi |
| Accuracy | ±10% within rated conditions |
🚒 Typical Applications
Inline foam inductors are commonly used for mobile firefighting and rapid deployment, including:
Fire brigade hose-line foam operations
Fuel spill fires
Tank farm protection (manual response)
Aircraft rescue firefighting support
Chemical storage areas
Marine and offshore emergency response
Industrial plants requiring portable foam capability
🔍 Installation Method
The device is installed directly in the hose line, typically:
Water Source → Inline Foam Inductor → Foam Hose → Foam Nozzle
⚠️ A matching foam nozzle is required to maintain the correct back pressure for proper induction.
✅ Advantages
✔ Lightweight and portable - ideal for emergency use
✔ No electrical or mechanical drive required
✔ Quick setup with standard fire hoses
✔ Cost-effective solution for foam application
✔ Reliable and easy to maintain
⚠️ Important Limitations
Must operate at the exact rated flow and pressure to induct properly.
Excessive hose length or elevation after the inductor can stop foam pickup.
Not suitable for large fixed systems or variable-flow applications.
Requires flushing with clean water after each use to prevent residue buildup.
Foam container should not be positioned above the inductor inlet level.