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#61 - Fire Sprinkler Head Types: Pendents, Uprights, Sidewalls, and Concealed

Posted by Jason Hugo, Courtney Montanye and Anna Hartenbach on 12/29/2016 to Fire Sprinkler System Components

If you're considering installing fire sprinklers in a new building or need to replace existing sprinklers, it is very important to understand the different fire sprinkler types. The form and shape, as well as the use and purpose, differs among sprinkler head types. Sprinkler heads are available in four primary types including pendent, upright, sidewall, and concealed. 

Once you've selected a type, additional options become available including temperature, finish, and response type. While we will address the options throughout this article, it is important to know that each type of fire sprinkler meets a different need so therefore getting the right sprinkler is paramount. But don't worry, by the time you finish this article you'll know exactly which type you need!

If you already know the type of fire sprinkler you need, QRFS offers a full selection of Tyco, Victaulic, and Senju fire sprinklers.

How do fire sprinkler heads work?

Functionally, the way fire sprinkler heads work is fairly simple: the glass bulb is filled with a glycerin-based liquid which expands to break the bulb at a specified temperature. Once that happens, the flow of water held back by the bulb flows out towards the deflector which disperses it on to the fire.

While there are numerous options when it comes to a fire sprinkler head, they all perform the same basic function: containing and extinguishing fires. Additionally, nearly all fire sprinklers are composed of the same components: a sealing assembly or ‘plug’, a temperature-sensitive glass bulb, a deflector, and a frame. 

Common wet fire sprinklers are available in two primary sizes: 1/2" and 3/4". A 1/2" sprinkler is the most common for office buildings, hotels, and schools. 3/4", on the other hand, are larger and used when extended coverage is necessary. For the purpose of this article, we're only going to highlight 1/2" sprinklers but most manufacturers also offer 3/4" variants, too.  Call us or browse QRFS.com to see your options.

Fire sprinklers are offered in various finishes, as well. Each manufacturer offers different options but most common are chrome, white, and brass.

Components-Fire-Sprinkler-Head
Figure 1: Fire Sprinkler Head Components

Sprinkler bulb temperature ratings

The temperature rating determines the ceiling temperature at which the sprinkler will activate. Options range from 135 to 360 degrees Fahrenheit, which is easily recognizable by the bulb color. 

See the bulb in Figure 1? The diagram on the right side shows bulb colors with their corresponding temperatures. When selecting a fire sprinkler head, this is an important consideration you definitely do not want to gloss over!

NFPA-Table 
Figure 2: Table from NFPA 13 6.2.5.1 

Standard vs. Quick Response

Finally, there's the option of standard response or quick response, which determine reaction speed and, more importantly, the sprinkler's mission. 

The main physical difference between standard response and quick response fire sprinklers is the size of the bulb. Quick response sprinklers have a smaller bulb, leading to a slightly faster response time. If you want to learn more about the response types and their specific objectives, check out this blog. 

What is a fire sprinkler K-Factor? 

A fire sprinkler K-Factor is the designation assigned to a fire sprinkler head based upon its discharge rate from the nozzle.
 
A fire sprinkler head with a higher K factor has the ability to discharge more water at a given pressure. The most common K factors for fire sprinklers are 5.6k for one-half inch and 8.0K for three-quarter inch sprinklers. 

So with this quick background out of the way, let's move on to exploring the four primary types of fire sprinklers: pendent, upright, sidewall, and concealed.

Pendent Sprinkler Head

The most common type of fire sprinkler head is the pendent. A pendent fire sprinkler protrudes and hangs down from the ceiling, like a pendant necklace but spelled differently.
 
Pendent fire sprinklers commonly require an escutcheon to cover the cutout in the drywall or drop ceiling surrounding it. Once water is expelled onto a pendent fire sprinkler's deflector, it sprays in a circular pattern providing the most coverage of any fire sprinkler. The deflector is curved downward, which helps to direct the water out into a cone pattern. Commercial pendent fire sprinklers are bet used in offices, hotels, factories, etc. 

TY323 Pendent Fire Sprinkler TY325 Pendent Fire Sprinkler

Upright Sprinkler Head

Upright fire sprinklers stand upright...imagine that! An upright sprinkler sprays water upwards and the deflector, which is curved, deflects the water back down to produce a hemispherical spray pattern. 

Don't they look like upside down pendent sprinklers?


TY313 Upright Fire SprinklerTY315 Upright Fire Sprinkler

Upright fire sprinklers are suited for areas that are difficult to access, like around beams, ducts, and other ceiling obstructions, or in ceilings without a finish (eg., no drop ceiling or drywall). These sprinklers are commonly found in buildings with exposed ceilings, like many chic restaurants or mechanical rooms. It may be useful to think of an upright fire sprinkler like an upside down pendent fire sprinkler, only with a concave deflector.

Sidewall Sprinkler

It's probably easy to figure out where a sidewall fire sprinkler is meant to be installed. They protrude through the wall and basically only have half of a deflector, which sprays water in a half circle or crescent shape. 

They're designed to protect small rooms, hallways, and other areas where sprinkler pipes are running up walls but not in the ceiling. You've probably seen one in a hotel room, where they are most commonly found. They are designed to be installed on the wall, instead of in the ceiling, along or under a beam. However, sidewall sprinklers perform the same basic functions as other fire sprinklers.

TY3331 Sidewall Fire SprinklerTY3351 Sidewall Fire Sprinkler

Concealed Sprinkler Head

Concealed fire sprinklers are somewhat like pendent fire sprinklers; however, they're located within the ceiling and they're hidden by a cover plate. Once the cover plate is installed, you can't see the concealed fire sprinkler at all. The cover plate will fall off at a temperature about 20 degrees lower than the fire sprinkler, allowing the deflector of the concealed sprinkler to drop and be exposed to the heat from the fire.

While the finish of the cover plate might concern you more than the finish of the concealed fire sprinkler itself, these fire sprinklers are available in brass and are available in quick response and standard response. The cover plates are available in white, chrome, and black, with special colors available upon request. Word to the wise: whatever you do, do not paint fire sprinkler cover plates.

TY3531 Concealed Fire SprinklerTyco Concealed Pendent with Cover Plate RFII


So now that we've reviewed the primary fire sprinkler types it is important to point out that these are far from the only types and options available. Over the years, fire sprinkler manufacturers like Tyco have developed many specialty sprinkler heads for very specific applications. Extended Coverage Light Hazard (ECLH), Extra Large Orifice (XLO), vertical sidewalls, and even mist systems are all different types of fire sprinklers. However, those are a topic for another day.

Fire Sprinkler Types

In conclusion, there are four primary types of basic fire sprinklers: pendent, upright, sidewall, and concealed. They are all available in a variety of temperatures, finishes, and size. 

There is no "best" fire sprinkler, there is only the right fire sprinkler for your specific application. That is why, when considering adding fire sprinklers to a new building, it is critical that you hire a licensed fire sprinkler designer to make sure the sprinkler type, location, and temperature meet the room size requirements necessary to effectively protect the room. 

If you're considering replacing fire sprinklers, note that the system must be drained in advance.

So now that you are an expert in the four most common fire sprinkler types, click the link below to explore QRFS' selection of commercial and residential fire sprinklers. We stock the four types from Tyco, Victaulic, and Senju Sprinkler. We pride ourselves on outstanding customer service, so if you have questions or concerns just give us a call at 888-361-6662. Otherwise, click the link, order your sprinklers, and we'll deliver them to you promptly!

BROWSE ALL COMMERCIAL FIRE SPRINKLER HEADS

This blog was originally posted by Jason Hugo and Courtney Montanye at QRFS.com/blog on December 29, 2016 and updated by Anna Hartenbach on July 30, 2017. If this article helped you find the right fire sprinkler head type to meet your needs, let others know on Facebook.com/QuickResponseFireSupply or on Twitter @QuickResponseFS.

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