4 Types of Fire Sprinkler Systems and Their Uses

4 Types of Fire Sprinkler Systems and Their Uses

4 Types of Fire Sprinkler Systems and Their Uses

4 Types of Fire Sprinkler Systems and Their Uses

Buildings should be equipped with automatic fire sprinkler systems because it help to control and reduce the risk to life and property from fire damage. According to the paper “NFPA 13, Standard for the Installation of Sprinkler Systems,” there are four different types of fire sprinkler systems, as specified by the NFPA. These systems are:

  • Wet pipe sprinkler system
  • Dry sprinkler system
  • Pre-action sprinkler system
  • Deluge sprinkler system overview

The term “other type of system refers to such as water mist systems and gas/clean agents, which are regulated by other standards such as NFPA 750, Standard on Water Mist Fire Protection Systems, and NFPA 2001, Standard on Clean Agent Fire Extinguishing Systems.

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    What is a sprinkler system?

    Sprinkler systems are made to start upon the detection of heat/fire in the area, then spraying water in that area where it is happening, this removes the fire from the start, suppressing and maintaining the fire within a building.

    Simple systems’ components include:

    • Individual sprinkler heads / multiple sprinkler heads
    • Pipework
    • Automatic control valve
    • Alarm system
    • Permanent water supply
    • Water tank
    • Sprinkler pumps

    Automatic sprinkler systems help detect fire, operate and deliver water to suppress and control, and extinguish the fire.

    Why install a sprinkler system?

    Automatic sprinkler systems will form part of the overall strategy to meet the local, national, and insurance needs of the building, space, and client. Here are some common reasons to install Fire sprinkler system which are:

    • To meet local building codes
    • To comply with national safety standards
    • To reduce insurance costs
    • To protect lives and property
    • To limit fire damage
    • To increase building safety
    • Business continuation
    • Concern about environmental impacts if a fire happens

    Fire Sprinklers will usually be integrated overall building with a life safety strategy. 

    Where are sprinkler systems installed?

    Sprinklers are installed in different types of buildings to provide protection based on the type of structure, space usage, and hazard being controlled. They can be divided into ‘Commercial, Industrial & Residential’.

    • Commercial buildings
      • Offices
      • High rise buildings
      • Shops
      • Hotels
      • Data centers
      • Parking garages
    • Public Buildings
      • Hospitals
      • Libraries
      • Sports halls
      • Schools
      • Museums
      • Historic buildings
    • Industrial
      • Factories
      • Laboratories
      • Warehouses
      • Storage facilities
      • Aircraft Hangar [uses foam water]
    • Residential Sprinklers
      • Houses
      • Flats
      • Apartments
      • Care Homes

    List Of 4 Types of Fire Sprinkler Systems

    There are four types of Sprinkler systems:

    1. Wet pipe sprinkler system
    2. Dry sprinkler system
    3. Pre-action sprinkler system
    4. Deluge sprinkler system overview

    1. Wet pipe sprinkler system 

    The most popular kind of sprinkler system is a wet pipe sprinkler system because it is easy to use and reliable. The pipework/system is always filled and charged with water, with the water release from the system occurring when heat is produced at a high level from the fire, finally breaking a glass bulb within a ‘sprinkler head’, allowing water to flow from the sprinkler pipe into the area.

    Depending upon the size of the fire, the number of sprinkler heads began will run. If the fire is small, then only one head sprinkler system will be required. The water pressure and release speed at the head are held with sprinkler system pumps (jockey/main) that will automatically switch on when there is an overall drop in system pressure.

    A valve is usually installed on the branch, and this will keep the system and send an alarm to the fire control system if a problem within the pipework is noticed.

    Wet sprinkler system procedure

    Here is a very high level of the wet sprinkler procedure:

    • Pipework is fully wet
    • Fire begins in space
    • Ambient temperature near the sprinkler head
    • Ambient temperature near sprinkler head over sprinkler head bulb temperature
    • The sprinkler head system breaks
    • Immediately water was released locally to fire
    • Pumps start when the system detects a pressure drop.

    2. Dry sprinkler system

    The most common type of system is a wet pipe sprinkler system because it is reliable and easy to use. They are mainly used within unconditioned areas when there is a risk of freezing temperatures, which would cause problems if the pipework was charged with water and frozen when required to start.

    To ensure the system only responds when there is a pressure drop, the control valve opens, allowing water to flow, and the empty pipework is filled/charged with pressurized air or nitrogen. Activation occurs in a similar way to the wet system: a sprinkler head starts, allowing air to pass through to the area, decreasing the pressure in the pipework, and starting the control valve and system pumps.

    They should not be noticed as a ‘pre-action’ system, as they work on a single interlock (air pressure drop), while a pre-action system performs on a double interlock.

    Dry sprinkler system Procedure

    Here is a very high-level dry sprinkler system procedure:

    • Pipework is dry (no water contained)
    • Fire starts in space
    • Ambient temperature builds up around the sprinkler head
    • Ambient temperature around the sprinkler head exceeds the
    • Sprinkler head bulb temperature
    • Sprinkler head breaks
    • Drop in pressure noticed by the system
    • Control valve opens
    • Water fills pipework
    • When the system notices a pressure drop, pumps turn on.
    • Water locally released through the head to ignite

    3. Pre-action sprinkler system

    A pre-action sprinkler system is more complex but generally used where accidental water release would be catastrophic, such as in data centers or museums.

    There are 3 sub-types:

    A non-interlock system starts the pre-action valve upon operation of a detection device (heat detector, smoke head, infrared sensor) or sprinkler head (pressure drop). This type provides little protection from accidental activation.

    A single interlock system starts the pre-action valve upon activation of any detection device (heat detector, smoke head, infrared sensor), allowing water to flow into the pipework and system.

    A double interlock system, the most common type, starts the pre-action valve upon operation of both a detection device (heat detector, smoke head, infrared sensor) and a sprinkler head (pressure drop).

    4. Deluge sprinkler system overview

    Deluge sprinkler systems are similar to pre-action systems, using a single interlock (the detector) to control water release. Deluge sprinkler heads are installed in dangerous areas and are ‘open.’ Once the overflow valve is started and water is in the pipework, the heads will instantly release water into the area, not depending on a bulb in the sprinkler head to break, allowing for a very fast response time. They will release water into the whole space from every head, not just local to the fire as with systems that use sprinkler heads with bulbs.


    Buildings benefit from automatic fire sprinkler systems to mitigate risks to life and property. NFPA identifies four main types: wet pipe, dry pipe, pre-action, and deluge systems. Each serves specific purposes and is crucial for meeting building codes, safety standards, and insurance requirements. Sprinkler systems are essential components for safeguarding various structures, including commercial, industrial, and residential buildings. The most common type is the wet pipe system, utilizing water as the primary extinguishing agent. Overall, these systems play a vital role in fire protection and ensuring the safety of occupants and assets.


    The Wet Pipe Sprinkler System.
    Water is the liquid used and released onto the fire. It is usually supplied from a water storage tank that is connected to the utility supply.

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