Bele High Expansion Generator – UL Variant

General description

Aspirated-type high expansion foam generators (HEGs) are designed to expand foam into a large volume of stable bubbles. Expansion rates up to 856:1 are possible due to jet streams of foam solution that aspirate a sufficient amount of air, which is then entrained onto perforated screens to produce high expansion foam. This high performance is achieved without any external power source or moving parts, which gives advantages for installation and reduces ongoing maintenance requirements.

High expansion generators are usually part of a fixed deluge or flow control system and shall be used in combination with a suitable foam proportioning system. Foam concentrates developed and tested to work in high expansion systems shall be used. It is critical to select a combination of generator and foam concentrate that have been developed and tested together to ensure critical parameters are achieved such as expansion, submergence height and fire performance.

High expansion foam systems are commonly used on hazards such as ordinary combustibles, flammable and combustible liquids or liquefied natural gas (LNG) for example. Such hazards are commonly found in applications such as aircraft hangars, warehouses, LNG facilities, cable tunnels, underground storage or recycling plants. High expansion foam systems should be brought into operation very quickly after the onset of fire so suitable detection and actuation systems should be provided.

This technical data is intended for trained experts. For further information, please contact Fomtec or refer to the technical documentation. The contents of this publication are subject to modifications without notice.

Listings and approvals

The high expansion generator is UL Listed (UL139) as part of a fire extinguishing system combining designated foam concentrate, proportioning devices and bladder tanks.

Listed system components can be found at


  • UL Listed GLHZ EX28465 – Generators, High expansion Foam


  • UL Listed GLKX EX27989 – Liquid Concentrates, High expansion Foam


Tested in accordance with EN13565-1

Standard materials, KGH 10000 - High expansion generator

Generator inlet connection KGH10000 - 3” (88.9 mm) Grooved (Single and Paired version)
Nozzle manifold Carbon steel ASME SA106 Gr.B or stainless steel ASME SA312 Tp.316
Nozzle manifold support arm SA516 Gr.70
Nozzle Brass EN CW614N
Body Stainless steel AISI-430
Support arm nuts, bolts & washers AISI-304
Finish – Nozzle manifold RAL3000 Flame red
Finish - Body Natural

Technical data,
Construction features


  • 2 size options for design flexibility
  • No moving parts and no external power requirements
  • Reduced/no generator maintenance which mitigates associated costs of testing
  • Listed with Fomtec LS xMAX 3% Synthetic Fluorine Free Foam (SFFF)
  • Vertical or horizontal installation



1 UL Listed parameters
2 Supply pipework can be a smaller diameter according to hydraulic calculation.
GPM = Gallons per minute, LPM = Litres per minute

Standard design specifications, model KGH10000 Single

Inlet size 3" 2
Working pressure, minimum, psi 40
Working pressure, minimum, bar 2,8
Working pressure, maximum, psi 103
Working pressure, maximum, bar 7,1
Flow range, minimum, GPM 77
Flow range, minimum, LPM 291
Flow range, maximum, GLM 118
Flow range, maximum, LPM 447
Nozzle qty 4
Weight, lbs 159
Weight, kg 72

Technical data,
Construction features

  • Stainless steel body with carbon steel or stainless steel flow manifold
  • Fixing points included
  • Heat and fire resistant to UL139
  • Foam expansion up to 856:1 (depending on model and supply conditions)
  • Grooved inlet connection
  • Suitable for the protection of Class A and Class B commodities according to recognised design and installation standards such asNFPA11, NFPA409, UFC 4_211 and EN13565-2
  • Innovative nozzle design to maximize performance and minimize clogging


1 UL Listed parameters
2 Supply pipework can be a smaller diameter according to hydraulic calculation.
GPM = Gallons per minute, LPM = Litres per minute

Standard design specifications, model KGH10000 Paired

Inlet size 3"
Working pressure, minimum, psi 40
Working pressure, minimum, bar 2,8
Working pressure, maximum, psi 103
Working pressure, maximum, bar 7,1
Flow range, minimum, GPM 154
Flow range, minimum, LPM 582
Flow range, maximum, GLM 236
Flow range, maximum, LPM 894
Nozzle qty 8
Weight, lbs 411
Weight, kg 186

Ordering information

1 ) Select the required generator model based on project requirements and performance data in Section 7.

2) The Paired generator consists of two single units combined with a fixing bracket and flow manifold.

3) Select the flow manifold pipe material

Scope of delivery

Ensure that all components are complete and in good condition. Note: Due to the size of the high expansion generator, logistics planning is recommended at initial order stage.


Unit is supplied with nozzles pre-installed into flow manifold pipework. Main body supplied with fixing bracket.To enable manageable handling and reduce logistics costs the flow manifold is shipped inverted inside the generator body. Site assembly of the body to the flow manifold is required. The paired version requires the 2 single generators to be site assembled to the centre bracket. Nuts, bolts and washers are supplied. For additional information, please refer to Operation & Maintenance Manual TM2.3.4.25.

Not Included

Fixing material, inlet connection coupling & optional strainer.


Please contact Fomtec for further information.

Product variants

Non-standard connections may be available on request

Strainer (see section 13)

Different packaging options according to project volume and location

Performance data

When planning, installing and commissioning high expansion foam systems it is extremely important to use system components that have been tested together. The link between the high expansion generator and foam concentrate is very important as the resulting data is essential in the design calculations of the system. Foam concentrate should also be compatible with the selected proportioning system and foam storage tank.

Notice: The following data is based on the high expansion generators referenced in this data page working together with specific foam concentrates at their tested flow rates and pressures. Actual site conditions may produce different results.

Submergence height

The height of the building and storage is an important factor to consider during design. The LS xMAX 3% foam concentrate has been tested at heights in excess of 25 metres. Consideration shall be given in the system design calculation that the higher the submergence height then the higher the correction factor for foam collapse might be. Test data obtained independently of the UL Listing.

Please contact your local Viking office for further information.

High expansion foam concentrate

The following foam concentrate is Listed and certificated with the KGH series of aspirated high expansion foam generators detailed in this data page.

(1) UL Listed as a system comprising foam concentrate, high expansion generator, proportioning devices and bladder tank
(2) Tested to the requirements of EN13565-1:2019 including Annex D (Heat and fire resistance test)
(3) Part 1 = Medium expansion foam concentrates for surface application to water-immiscible liquids (hydrocarbons)
(4) Part 2 = High expansion foam concentrates for surface application to water-immiscible liquids (hydrocarbons)
(5) Part 3 = Low expansion foam concentrates for surface application to water-immiscible liquids (hydrocarbons)
(6) Part 4 = Low expansion foam concentrates for surface application to water-immiscible liquids (polar solvents)
(7) Please refer to foam concentrate data page or product sheet for detailed technical information

High expansion foam concentrate

Foam concentrate (7) Fomtec LS xMAX 3%
Type Synthetic SFFF
UL(1) yes
EN13565-12-1 (2) yes
EN1568 Certification, Part 1 (3) yes
EN1568 Certification, Part 2 (4) yes
EN1568 Certification, Part 3 (5) yes
EN1568 Certification, Part 4 (6) no


Refer to appropriate installation standards (i.e. NFPA, EN13565-2 etc.) In addition, the “Authority Having Jurisdiction” (AHJ) may have additional installation requirements that must be followed. Some key system related requirements are detailed in this section. For detailed information on the high expansion generators installation, please refer to Operation & Maintenance Manual TM2.3.4.25.


The high expansion generator can be installed in the vertical or horizontal position with a comparable performance.


It is good practice to ensure the water foam solution fed into the nozzle manifold during operation is free of debris. For this reason, we recommend a main system or individual generator strainer with screen size of 4-5 mm.


High expansion foam systems should be activated quickly after the onset of fire, so suitable detection and release systems need to be provided, e.g. e.g. Viking UniVario Industrial Detectors and/or Viking control and release panels. Detection via heat activated bulbs or links such as sprinklers shall not be used due to the inherent delay of operation.

Proportioning equipment

The Listed high expansion generator and foam concentrate are approved and compatible with bladder tanks and ratio controllers detailed in the UL system Listing. Other listed and/or approved proportioning technologies such as pump skids with Listed ILBP’s or water driven pumps can also be used.

Single unit connection

Both the single and paired generators have a 3″ grooved connection. The single generator configuration can be fed with smaller diameter pipework according to hydraulic calculations.


High expansion foam generators are part of a fixed fire protection system incorporating a water supply, system pipework, foam concentrate, foam storage tank and proportioning / admixing system.

In a fire condition, the detection system will activate and sound the warning alarms. The deluge or flow control system(s) will then be opened via a releasing panel working in conjunction with the detection system. It is generally accepted that this delay will be around 30 seconds, giving time for activation before the discharge begins. Once the deluge or flow control valve is in operation, the incoming water supply is mixed with the foam concentrate using a proportioning / admixing system thereby creating foam solution. Once the system pipework has filled and is up to the required pressure – high expansion foam discharge will begin.

The protected area will be filled within a certain submergence time which is defined during the planning/design phase. The high volume of foam is design to suffocate the fire resulting in suppression or extinguishment. The submergence volume should be maintained as per the applicable design rules applied.

Once the fire is extinguished, the high expansion foam can be left to break down naturally or for a quicker cleanup, a fine hose spray can be employed to break down the bubbles. It is recommended to add an “Anti-Foam” compound to the resulting foam solution to assist with the collection and transfer of the foam solution to prevent agitation and re-foaming.


For details of warranty, contact Fomtec directly.

Inspection, tests and maintenance

Refer to respective requirements of NFPA and/or EN13565-2. In addition, the “Authority Having Jurisdiction” (AHJ) may have additional maintenance, testing and inspection requirements that must be followed.

For manufacturer’s additional recommendations and requirements, please refer to Operation & Maintenance Manual TM

Notice: The owner is responsible for maintaining the fire protection system and devices in proper operating condition.

Warning: Any system maintenance or testing that involves placing a control valve or detection system out of service may eliminate the fire protection capabilities of that system. Prior to proceeding, notify all Authorities Having Jurisdiction. Consideration should be given to employment of a fire patrol in the affected area.


At end of use the product described here should be disposed of via the national recycling system. Upon request the manufacturer can take back and properly dispose of the electrical equipment and electronic devices.

Declaration of confirmity

If required. Contact Fomtec for further information.