Foam Water Sprinkler System

An automatic sprinkler system is designed to distribute water or foam solution to a specific hazard area. The application rate, commonly referred to as ‘‘ density,’’ is frequently expressed in units of gallons per minute per square foot ( gpm/ ft2) or liters per minute per square meter (Lpm/m2) of area.

The worst potential fire situation is generally used to determine the number of sprinkler heads discharging. This, in turn, determines the water supply demand; and in the case
of foam sprinkler systems, the required amount of foam liquid concentrate. Characteristics of some flammable products may require higher densities and special foam liquid

Areas protected by sprinkler systems are usually given a class of occupancy (light, ordinary, or high hazard). The class of occupancy relates to the probable number of sprinkler
heads that may operate in a particular fire situation and governs the maximum spacing allowed between sprinkler heads. The sprinkler head provides for a nearly uniform distribution of water or expanded foam over a given area. The solution strikes a deflector and is broken into a circular pattern of distribution. Spacing of sprinkler heads results in overlapping patterns to ensure uniform coverage and effective fire control.

Pipe sizing to the sprinkler heads is commonly determined by hydraulic calculations to assure an adequate supply of water and uniform distribution from the sprinkler heads. The standard addressing sprinkler system design is NFPA Standard 13 or BS EN12845. Additional guidance for foam systems design is contained within NFPA Standards 11, 16, and 30.

Types of Sprinkler Head

Conventional sprinkler heads

sprinklers Conventional sprinklers heads are available for either upright or pendent installation. A heat sensitive element, consisting of either a fusible link or frangible glass bulb, is rated for a specific operating temperature. A standard orifice sprinkler is 15mm; however, various small and large orifice sprinklers are available to achieve the desired density with the available water supply pressure.

Conventional open sprinkler heads, without the heat-sensitive element, are used for total area flooding “deluge” systems. In applications using AFFF concentrates, the conventional sprinkler is acceptable. The UL listing directory should be consulted to ensure the sprinkler head is listed with the manufacturer’s foam concentrate.
Acceptable foam quality is expected from conventional sprinkler heads of similar design to those listed. These sprinklers cannot be used with protein or fluoroprotein base foam concentrates which require air aspirated discharge devices.

Foam/water sprinkler heads

sprinklers Foam/water sprinkler heads are open type and generate air aspirated foam by drawing air into the foam solution stream. The sprinkler head is available for either
upright or pendent mounting and may be used with either foam or water. Patterns of coverage are similar to conventional sprinkler heads; however, only a 3/8 in. orifice is
available corresponding to a K-Factor of 3.0.




Types of Sprinkler Systems

Sprinkler systems can be either closed-head or open-head (deluge) systems using conventional sprinkler heads. Sprinkler systems using foam/water sprinkler heads can
only be open-head systems as these sprinklers are not available with heat-sensitive elements. Closed-head sprinkler systems can be of three different types: wet pipe, dry pipe, or preaction. An AFFF foam can be used in any closed-head sprinkler system as covered by NFPA Standard 16 – Foam/ Water Sprinkler Systems.

The following types of system are generally used

Wet Pipe System -  click here for further information

Dry Pipe System – click here for further information

Preaction System – click here for further information

Deluge System – click here for further information


Technical Datasheet Downloads

Approved Sprinkler Head list for Foam Concentrates

Type B1 Foam Water Sprinkler Datasheet

Type TF Foam Discharge Head

Tyco Acquires Chemguard

Chemguard Logo

Tyco International has announced that it has acquired Chemguard Inc. Including Chemguard’s subsidiary Williams Fire and Hazard Control Inc.  The acquisition was transacted through the Fire Protection Products business and will allow Tyco to broaden it’s product and services portfolio in specialty chemicals, foam and foam hardware and firefighting services.

Please see the Tyco Press Release for further information.


InControl Fire Protection is the Tyco Authorised Distributor for foam products in Ireland and can provide assistance etc in design and specification of fire protection systems using foam products.

You can find more information regarding Fire Fighting Foam Products and Systems on our website –

We would welcome the opportunity to assist you on any projects you are working on and can provide independent advise on the different options available.

The combination of Ansul and Skum products (both part of the Tyco Fire Suppression and Building Products) cover a wide range of approvals including F.M.,  U.L. Listing, B.V., ABS etc.

Please contact us know if you require any further information or assistance with budgets, specifications etc.

InControl Limited
Zion Court
Zion Road
Dublin 6
Ph: +353 1 494 1429
Fax: + 353 1 492 6622

Deluge Sprinkler System

In the deluge system, all sprinklers are open and normally there is no water in the piping. When fire occurs, a supplementary detection system senses the fire and automatically
opens a water control valve. This allows water to flow through the piping system to all sprinklers.


Deluge System

Preaction Sprinkler System

In a preaction system, all sprinklers are closed and normally there is no water in the piping. A preaction system is used when faster response is desired (versus a dry pipe system). When fire occurs, a supplementary detection system (more sensitive than the sprinkler elements) senses the fire and automatically opens a water control valve which
allows water to flow into the piping system. Subsequent water discharge occurs from individual sprinklers as they respond to the heat of the fire. The system shown below uses HAD’s (Heat Actuated Detectors) and a dropweight release to open the preaction valve. Alternate detection systems can also be used. Pre-priming foam solution is not needed as foam will be proportioned into the piping during operation.

PreAction System

Dry Pipe Sprinkler System

Dry pipe systems use automatic sprinklers that are attached to a piping system containing air under pressure. When the air is released from the opening of the sprinklers, the water pressure overcomes the lessened air pressure and opens the dry pipe valve. The dry pipe valve is designed so that a moderate air pressure prevents a higher water pressure from opening the valve.

Once the valve is opened, the water flows into the piping system and out the opened sprinklers. This system provides protection in areas subject to below freezing temperatures. Piping must be drained of water or foam solution following operation to prevent freezing.

Typically, upright sprinklers are used to allow drainage.  Otherwise, approved dry pendent sprinklers must be used to prevent freezing. Dry pipe systems are inherently slower in operating and should be considered less desirable for applications using AFFF.


Dry Pipe System

Wet Pipe Sprinkler System

This system uses automatic closed-head sprinklers that are attached to a piping system containing water. Water discharges immediately from those sprinklers opened by a fire. A flow of water through the valve sounds an alarm.

Wet pipe systems should not be used where freezing conditions are likely to damage piping. In systems using AFFF concentrate, the piping to the sprinkler heads can be pre-primed with foam solution to enable immediate effective foam discharge. AFFF solution in contact with steel pipe may gradually lose its fire effectiveness. Samples of this solution should be checked on an annual basis and replenished as needed. A test discharge connection is recommended downstream from the proportioner and should be located to fill a maximum portion of the sprinkler system piping. The test connection should be of sufficient size to meet the minimum flow rate for the particular proportioner. This type of system is the most reliable, simplest, and fastest responding of all closed-head sprinkler systems. Conversions of water systems to foam can usually be accomplished easily. (Local codes and regulations should be investigated prior to conversion.)

Wet Sprinkler System

Technical Services

Contact us on +353 1 494 1429 for further information

New Developments in Bladder Tanks

VertBladTnkInstalIn the past there have been two problems associated with bladder tanks – the possibility of the bladder rupturing and also the inability to refill the unit during operation because it is pressurised.

Both of these problems have now been tackled and resolved by SKUM.

Unique fixing and support methods now employed by SKUM now ensure the integrity of the bladder while still maintaining the ease of bladder installation and operation.

The problem of refilling during operation has also been overcome by providing a pressurised source of foam concentrate from a mobile unit as an optional extra to the basic tank supply.  The optional mobile unit also provides a simple means of refilling after operation.

The list of advantages for bladder tank usage has now been re-written as follows:-

  • Few moving parts
  • Low Pressure Drop
  • Variable Flow capability
  • Can be used with all types of foam concentrate
  • No external power source required
  • Can be refilled during operation
  • Can easily be used in automatic systems
  • Can meet the requirements of all internationally recognised design codes

Please contact us for more information on +353 1 494 1429

Download product datasheet

Foam Vs Combustion

In order to understand how foam suppresses fire, it is first necessary to understand the process of combustion.

Combustion is a process where fuel undergoes a rapid exothermic chemical reaction (release of heat) with an oxidizing agent, usually air, resulting in the formation of products of combustion and energy (fire).


A fuel is any material that can be oxidized; it can be a solid, liquid, or gas and is generally organic in nature, i.e., composed mostly of carbon, hydrogen, or oxygen. The products of combustion of an organic fuel (assuming complete combustion) are carbon dioxide and water. The energy released may be in the form of heat or light, or the combination of heat and light (fire).

The chemical reaction is not a simple one-step reaction, but is a chain reaction resulting in a number of interdependent chemical reactions. Figure 1-1 depicts the four requirements for combustion using the “fire tetrahedron.”


It follows that any method for extinguishing fire must involve one or more of the following techniques:

  1. Remove heat at a faster rate than it is released.
  2. Separate the fuel from the oxidizing agent.
  3. Dilute the vapour-phase concentration of the fuel and/or oxidizing agent below that necessary for combustion.
  4. Terminate the chemical chain-reaction sequence.

Fire fighting foam is an aggregate of gas-filled bubbles (Figure 1-2) formed from aqueous solutions of specially formulated, liquid agent concentrates. The gas used is usually air, but certain applications use an inert gas.

Since foam is lighter than flammable and combustible liquids, it floats on the fuel surface producing a continuous blanket that suppresses fire by separating flammable vapours and oxygen as shown in Figure 1-2. Because foam is a water-bearing material, it also cools the fuel surface.


Designing a Foam System

In today’s society oil and its petrochemical derivatives play an ever-increasing role in our day to day life. New materials and chemicals are constantly being developed to meet the needs of an expanding and developing market place. Global economies are affected by the supply and demand of these commodities. In recent years, one major refinery fire incident in America had a massive impact, overnight, on oil prices internationally. With this back­ground it has become even more vital for Loss Prevention Engineers to ensure that flammable liquid assets are protected to the best degree possible.

Indeed, the protection philosophy applied must not only consider the consequences of an incident within a facility but also the effects on the environment and society outside.

In many cases the only effective solution to a major flammable liquid fire or unignited spill incidents is the use of foam – correctly selected and applied. Often, especially with decreasing plant manpower levels, this requires a fixed system. Nowadays there is a greater choice of foam agents and hardware available for this purpose, thus making the task of optimum system design much more complex.

In Control Fire Protection now have access to the most comprehensive range of foam equipment available from both Ansul and Skum, can assist and advise in the design process and make the task easier.

What is the risk protected

Before any system design can be carried out, it is obviously necessary to define the risk to be protected. This does not just mean finding out the dimensions of the hazard. The fuel type, availability of power supplies, area classifications, ambient conditions, water supply and site valve/pipework specifications may all have some bearing on final system design.

The most important point to remember is that the hazard to be protected should not be looked at in isolation. Even when the risk appears to be remote from others, a system designer should consider all relevant outside factors such as the local availability of compatible back-up foam stocks from neighbouring facilities. When several risks are present on one site it is particularly important to look at the worst possible fire scenario and make sure resources are available to tackle it.

All recognised international standards make it very clear that sufficient foam concentrate and application equipment must be available for the largest incident so the fire protection engineer must decide whether a fire in one hazard could escalate to others – or more importantly, can good system design with fast detection and rapid actuation prevent this happening?

Also, of course, it is often possible to provide more cost effective fire protection by serving several hazards from one central proportioning unit and foam concentrate supply. It is in these areas, with their wide range of experience of risk assessment and system design in all industry sectors that In Control Fire Protection can provide the most cost­ effective solutions to fire protection problems.

Although foam systems can be used for protection of combustible solids such as paper, by far the most com­mon use of foam is for the protection of flammable liquids. The type of liquid and its physical properties affect the type of foam to be used and the system running time required to assure extinguishment.

What foam should be used

In recent years there have been many new foams developed and introduced. Different generic types are available such as "protein" and "synthetic" based foams.

Undoubtedly the general trend is towards multipurpose foam concentrates that can be used on all types of fuel, but these may not be the most cost-effective in all cases.

Foam liquid manufacturers have increased the confusion by continuing the debate on what generic type is best. The truth of the matter is that the important thing is not what raw material a foam is made from but how the end product performs!

To perform effectively, several properties are needed from a foam. These depend on the accuracy of proportioning and method of application as well as on the foam concentrate.

The most important properties that a foam requires for effective fire extinguishing are:

  • Cohesion – to form a stable blanket on the fuel surface
  • Heat resistance
  • Burnback resistance – to prevent remaining fire burning off the foam blanket
  • Adhesion – to give sealing against hot objects in the fire
  • Vapour suppression – to prevent vapours rising through the foam blanket
  • Stability – to provide security against re-ignition. Stability is often measured in terms of "25% drainage time" which is the time taken for 25% of the foam solution required to make a given foam sample to drain from that foam. Longer drainage times mean greater stability
  • Flowability – to move rapidly across a fuel surface and around any obstacles in its path
  • Flame knockdown – to quickly control the fire
  • Fuel tolerance – to ensure that the foam is not broken down by contamination with the fuel. This is particularly important in the case of water soluble fuels such as alcohols, gasohols, ketones etc. as they break down standard types of foam.