Foam Proportioning Systems & Tanks
Fixed system Proportioning
Vertical bladder tank
The Bladder Tank is a core component of a Foam Bladder Tank Proportioning System and operates using only a pressurized water supply. A complete bladder tank system consists of the tank, internal bladder, proportioner, and associated hardware.
When the system is activated, water enters the bladder tank and compresses the internal bladder, forcing the foam concentrate through the proportioner and into the foam solution stream. The bladder tank automatically proportions foam concentrate across a wide range of flows and pressures and discharges concentrate at nearly the same pressure as the incoming water supply.
National Foam Bladder Tanks are steel, pressure‑rated vessels designed for long service life and reliable proportioning performance.Horizontal bladder tank
Horizontal Bladder Tanks function identically to vertical bladder tanks and are used where space or installation constraints require a horizontal configuration.
The system injects foam concentrate into the water stream of a fire protection system and automatically proportions it across a wide range of flows and pressures. Upon activation, water compresses the bladder and displaces the foam concentrate through the proportioner until the concentrate supply is depleted.
Bladder tank accessories
Bladder tank accessories support the operation and integration of Foam Bladder Tank Proportioning Systems. As with all bladder tank systems, operation relies solely on a pressurized water supply to proportion foam concentrate accurately and reliably.
Proportioners and controllers
Field proportioning test kits
Field Proportioning Test Kits (also referred to as Foam Test Kits) allow operators to quickly and reliably verify the solution percentage of foam concentrate while in the field.
Stationary diaphragm proportioners (SDP)
Stationary Diaphragm Proportioner units are self‑contained, dependable, high‑quality mini‑proportioners designed for single‑person operation. Each unit is equipped with a discharge hose, foam nozzle, and mounting support saddles for fixed installation.
In‑line proportioners
In‑line proportioners harness water flow to create a venturi effect that draws foam concentrate into the water stream at a calibrated rate. With no moving parts, these devices are cost‑effective, low‑maintenance, and reliable when sufficient water pressure is available.
Line proportioners
Line proportioners, also known as inductors or eductors, are venturi‑based devices that introduce foam concentrate into flowing water at a controlled rate. Their simplicity and lack of moving parts make them suitable for a wide range of foam applications.
Ratio controllers
Ratio Controllers are advanced in‑line venturi‑based proportioning devices designed to inject foam concentrate into the fire water stream without manual adjustment. They can proportion most foam concentrates across their applicable flow range regardless of pressure fluctuations.
Ratio Controllers are available in threaded (RCT), flanged (RCF), or wafer (RCW) configurations.Valves and balanced pressure systems
Water‑powered ball valves
Water‑powered ball valves are used in foam proportioning systems that require automatic foam concentrate discharge. These valves are actuated by the pressurized water supply and do not require external power or control signals.
Activation water may be supplied from a ratio controller sensing port, deluge alarm line, or alarm check valve. After system operation, the valve must be manually closed. Manual override capability is included, and in continuously pressurized systems, a solenoid valve may be integrated for positive shutoff.In‑line balanced pressure (ilbp) proportioning systems
In‑Line Balanced Pressure Proportioning Systems allow foam or water selection at each discharge device within a foam system without affecting accurate proportioning at other outlets.
ILBP systems consist of:
- Proportioning modules that control foam concentrate injection
- A pump system that supplies foam concentrate under pressure
ILBP modules are available in wafer, threaded, or flanged styles and may include integral check valves.
Supporting components include:
- Pressure Sustaining Valves to maintain preset foam discharge pressure
- Pressure Reducing Diaphragm Valves to balance foam and water pressures
- Foam Concentrate Jockey Pumps to maintain pressure in long or underground piping runs and meet NFPA requirements
Balanced pressure proportioning systems
Balanced Pressure Proportioning Systems use a foam concentrate pump and diaphragm‑operated pressure balancing valve to inject a calibrated percentage of concentrate into the foam‑water stream.
Balanced pressure proportioners
These fixed, skid‑mounted systems are widely used due to their accuracy and versatility. The skid‑mounted design allows the entire proportioning system to be pre‑assembled for straightforward integration into the onsite water supply.
Back Pressure Regulating Diaphragm Valves equalize foam and water pressures at the ratio controller inlet by recirculating a portion of foam concentrate back to the storage tank.
Foam pump systems (pump skids)
Injection‑type Balanced Pressure Pump Proportioning Systems accurately proportion foam concentrate over a wide range of flows and pressures without manual adjustment. These systems maintain equal pressure at the foam and water inlets to the proportioner and are typically installed with atmospheric foam concentrate storage tanks as an alternative to bladder tank systems.
Helijector foam proportioning system
The Helijector is a self‑contained, skid‑mounted foam proportioning system consisting of a foam storage tank, water turbine, foam pump, and interconnecting pipework. Built from materials approved for offshore use, all components are mounted within a durable steel‑framed skid.
Designed primarily for offshore helideck fire protection, the Helijector is available for constant flow rates of 900, 1800, or 2700 L/min at 7 bar using National Foam oscillating monitors. It is also suitable for fixed foam systems with known constant flow requirements.
The system operates without external power, relying solely on fire main water. Initial foam supply provides 10–30 minutes of operation, with the atmospheric storage tank replenishable during use for continuous operation.
The Helijector delivers:
- Fixed 1% foam solution (3% optional on 900 L/min systems)
- Automatic adjustment to water flow variations
- Consistent proportioning despite minor pressure fluctuations
Bladder tank foam proportioning systems
Bladder Tank Foam Proportioning Systems are widely used in fixed foam fire protection applications due to their simplicity, reliability, and ability to operate using only a pressurized water supply. A complete system consists of a bladder tank, internal bladder, proportioner, and associated hardware.
National Foam Bladder Tanks are steel, pressure‑rated vessels fitted with an internal elastomer bladder that stores foam concentrate. Upon system activation, water enters the tank and compresses the bladder, displacing foam concentrate through the proportioner and into the foam‑water solution stream. Foam concentrate is discharged at nearly the same pressure as the incoming water supply, allowing accurate proportioning across a wide range of flows and pressures.
Bladder tank systems are suitable for use with a variety of foam concentrates and are commonly applied in industrial, aviation, and flammable liquid hazard protection systems.
Balanced pressure proportioners
Balanced Pressure Proportioning Systems are widely used due to their versatility and precision. These fixed, skid-mounted units offer reliable foam protection for a variety of flammable hazards. The skid-mounted design enables the entire proportioning system to be pre-assembled on a single base, providing easy integration to the onsite water supply.
Back Pressure Regulating Diaphragm Valves are essential components of Balanced Pressure Proportioning Systems. They are designed to equalize the pressures between the foam concentrate and water supply at the inlet of the ratio controller by regulating the foam concentrate pressure at the valve inlet. The pressure balance is achieved by recirculating a portion of the foam concentrate back to the storage tank.
Foam pump proportioning systems (pump skids)
Injection-type Balanced Pressure Proportioning Systems—commonly referred to as pump skids—accurately proportion foam concentrate over a wide range of flows and pressures without manual adjustment.
By maintaining equal pressure at the proportioner inlets, these self-contained systems allow consistent foam delivery regardless of system conditions. Pump skids are typically installed with atmospheric foam concentrate storage tanks and are often selected as an alternative to bladder tank systems.
Polyethylene storage tank
Polyethylene Atmospheric Tanks for foam Concentrate storage come in a variety of sizes, ranging from 55 gallons to 11,900 gallons. Standard tanks are constructed and installed in a vertical configuration and are compatible with all National Foam concentrates.
Fixed system nozzles and sprinklers
Fixed system foam nozzles and sprinklers distribute foam over designated hazard areas. These air-aspirating discharge devices introduce air into the water-concentrate stream prior to discharge, producing expanded foam for effective fire suppression.
Foam makers and chambers are used to protect open- or floating-roof fuel storage tanks as well as diked spill areas. These devices are side-mounted on the tank interior and apply expanded foam directly onto the flammable liquid surface, suppressing fire and fuel vapors.
Fixed system foam nozzles and sprinklers spray foam over a designated hazard area. These air-aspirating devices are designed to create foam expansion by introducing air into the water/concentrate stream prior to discharge.