types of fire sprinkler heads

Fire sprinkler heads are one of the most important parts of fire protection system. There are so many types of fire sprinkler heads available in market. But among all, there are four main types.

Before going to discuss about types of fire sprinkler heads, let us have a look on

  1. Components of Fire sprinkler Head
  2. How Fire sprinkler Head works

What are the components of Fire Sprinkler Head?

In the following figure of fire sprinkler you can observe several components which are assembled together and finally forms into Fire sprinkler head.

The Fire Sprinkler Head is a combination of various components as mentioned below. They are:

  • Frame
  • Deflector
  • Heat Sensitive Element (Bulb / Metal Fuse)
  • Sealing Assembly (Plug)
  • Escutcheon
sprinkler components


The frame is a metal structure that holds all the remaining components. Such as Deflector, Bulb, Sealing assembly are fixed with it.


The Deflector is circular type metal structure. We can observe it in the above picture. It is fitted at the end side of the sprinkler. The function of deflector is to make the water spread in surrounding area.

Heat Sensitive Element

This part is the one which plays an important role in the function of fire sprinkler head. In some sprinklers it is made of glass bulb and in some other it is fusible metal link. Both glass bulb and metal link function is same. When surrounding temperatures reaches to specified level such as 57˚C (135 F) to 182˚C (360 F) they are activated and makes the water to flow from the pipes through the sprinkler head.

NOTE: Please read the article to know about “Temperature Ratings of Fire Sprinklers and their Color Codes

Glass Bulb

As shown in above image, the glass bulb is present between inside the frame.

  • The glass bulb consists of glyceiriene-based liquid.
  • In addition, when temperature around the sprinkler reaches to specified limit such as 57˚C (135 F) to 182˚C (360 F) the liquid inside the bulb expands and makes the glass bulb to be broken.
  • After the glass bulb broken the plug at the other end of bulb will release the water from the pipe.
  • The water then discharge from the pipe and hits the deflector.
  • Then it sprays water in conical shape to the area covered by sprinkler.
  • Glass Bulb is available in 3 mm and 5 mm thickness

Fusible Link

In some sprinklers instead of glass bulb there will be fusible metal link used.

Now you may be confused why and where fusible metal link sprinklers used instead of glass bulb.

Let us discuss why and where they are used

  • The areas in buildings, warehouses, cold storages where there are cold temperatures, this type of sprinklers are used.
Fusible Link Sprinkler
  • Moreover, the reason is, in cold temperature areas, the liquid in glass bulb is unable to expand when the temperature rises to certain specified limit such as 57˚C (135 F) to 182˚C (360 F).
  • However, the metal link is designed and made with special alloys, which is melted when the surrounding temperature reaches to specified limit such as 57˚C (135 F) to 182˚C (360 F).
  • Then the fusible metal link melts and makes the plug to release and spray the water from pipes towards deflector.

Sealing Assembly

Sealing Assembly is also known as Plug. The function of plug is to act as a seal to prevent escaping of water from pipes.We can observe the plug in the above picture.


Escutcheon is a cylindrical cap like component. Although not almost all sprinklers uses it, they used to cover the hole made around the sprinkler in the ceiling. Where aesthetic looks comes into consideration there this escutcheons are used.

Types of Fire Sprinkler Heads

Have you visited any commercial Buildings, Hospitals, Industrial ware houses?

If yes, then you can observe fire sprinklers fitted above in some required ceiling areas of these buildings.

You can also observe some fire sprinklers in corridors, side wall of stairs and also in basement. However all these fire sprinklers looks like same. But these all are different types of fire sprinkler heads used in different areas based upon their applications.

For example, in rooms the sprinkler heads are different and in corridors double height areas, basement floors are different.

Based on areas of application, the sprinkler heads are classified into four major types.

  • Upright Sprinkler Heads
  • Pendent Sprinkler Heads
  • Side Wall Sprinkler Heads
  • Concealed Sprinkler Heads

Now let us discuss one by one of the types of sprinkler heads by covering its area of application and how it looks like.

Pendent Sprinkler Head

These are most common standard types of sprinkler heads used in almost areas. This type of sprinkler head will have following features

  • This sprinkler will be fitted in downward direction
  • The deflector will be at bottom side.
  • The water is sprayed to downside in cone shape
  • It covers 3 to 4 sq. meters surrounding sprinkler area

Where Pendent type Fire Sprinkler Heads used?

  • Used in ceiling areas
  • Rooms, Corridors, where ceiling is available

Concealed Sprinkler Head

This sprinkler head is almost similar to pendant type. However, the variation between pendent and concealed pendent is it fitted inside the ceiling, which concealed with a cover plate.

When the temperature of surroundings reaches to 20% of the sprinkler temperature limit the cap will fall down and the sprinkler is exposed.

These concealed fire sprinkler heads are used where aesthetic look comes into priority level.


Upright Sprinkler Head

In its name only it is described the nature of its sprinkler.

  • These sprinklers are fitted quite opposite to pendant type
  • These are fitted in upward direction whose facing is upwards
  • The deflector in this sprinkler is in upside like umbrella as shown in figure
  • Here in this sprinkler the water moves in upward direction and hits the deflector plate
  • And sprays the water in hemispherical pattern covering the area
upright fire sprinkler head

Where upright type Fire Sprinkler Heads used?

upright sprinkler heads are used in

  • Where no false ceiling is available
  • In open area inside buildings
  • In parking areas
  • In Basement areas
  • In Industrial areas where it is double height

Sidewall Sprinkler Head

This type of sprinklers have the half-circled deflector plate as shown in figure.

  • These sprinklers fitted where pipe runs in no ceiling
  • They are fitted in sides of walls
  • The water is sprayed downwards to the sides of walls
Sidewall fire sprinkler head

Where sidewall type Fire Sprinkler Heads used?

  • These are used in side walls of stairs
  • Hallways, Double height reception area in side walls


As we discussed all about fire sprinkler heads, their working principle and its types, now you have an idea about Fire sprinkler heads.

Now based upon above content you can select which type of sprinkler is used for your building.

If you have any comments regarding the fire sprinkler heads, mention in the comment section below.

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By Naseer Shaik

Hi, I am Naseer Shaik, Mechanical Engineer. Present working as Plumbing and Firefighting Engineer in Kuwait. And also I am a Blogger, YouTuber.

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