888.361.6662 | Welcome, Guest Login | View Cart
Thoughts on Fire Blog Header

Together we'll make the world a safer place
Our opinion, news, and commentary on everything pertinent to the fire industry
Go to QRFS.com
+Jason Hugo

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

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

If you're considering fire sprinklers in a new building or need to replace existing sprinklers, it is very important to understand the different fire sprinkler 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?

While there are numerous options when it comes to a fire sprinkler head, they all perform the same basic function: containing and extinguishing fires. Most sprinklers are composed of a plug, a temperature-sensitive glass bulb, a deflector, and a frame. Functionally, it 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.

There's a range of options to consider for each sprinkler type. Arguably, the single most important is temperature, which determines at which ceiling temperature the sprinkler will activate. Options range from 135 to 360 degrees Fahrenheit, which is easily recognizable by the bulb color.

Thermal Sensitivity Ratings

The finish is also something to consider. Each manufacturer offers different options but most common are chrome, white, and brass. Finally, there's the option of standard response or quick response, which determine reaction speed and, more importantly, the sprinkler's mission. If you want to learn more about the response types and their specific objectives, check out this blog. 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.

Finally, 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 all the types listed below are available in 3/4" variants, too.

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.

Sprinkler Type 1: Pendent

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 pictures below show two different Tyco pendent fire sprinklers. The sprinkler on the left is the TY323 quick response in chrome. The sprinkler on the right is the TY325 standard response in brass. Notice the size difference in the bulbs - the TY323 is quick response, so the bulb is 3 millimeter, compared to the TY325's 5mm bulb. See how the deflector is curved downward? That is what helps direct the water out in a cone pattern.

TY323 Pendent Fire Sprinkler TY325 Pendent Fire Sprinkler

The Tyco pendent fire sprinklers used in this example are available in a range of temperatures from 135 to 360 degrees Fahrenheit and three standard finishes: chrome, white, and brass. Other finishes are available upon request.

Sprinkler Type 2: Upright

Upright fire sprinklers stand upright...imagine that! An upright sprinkler sprays water upwards and the deflector deflects the water back down. 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.

Take a peek at the two upright fire sprinklers below. The left is the TY313, which is quick response and the right is the TY315, which is standard response, both of which are shown in brass. Just like the pendent fire sprinklers, you can see the size difference in the bulbs, which, as you should know by now, correlates to the response type. If you look at the deflector, it's curved so that the water will deflect downward. Don't they look like upside down pendent sprinklers?

TY313 Upright Fire SprinklerTY315 Upright Fire Sprinkler

Just like pendent fire sprinklers, upright fire sprinklers are available in the temperature range of 135 to 360 degrees Fahrenheit. While they are available in chrome and white, the most common finish for an upright fire sprinkler is simply brass.

Sprinkler Type 3: Sidewall

It's probably easy to figure out where a sidewall fire sprinkler is meant to be installed. They protrude through the wall and spray water in a half circle. 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. Although they're designed to be installed on the wall instead of in the ceiling, they perform the same basic functions as other fire sprinklers.

If you look at the chrome sidewall fire sprinklers below, the left is the TY3331 and the right is TY3351. Can you guess which one is the quick response? The TY3331's bulb is noticeably smaller. The deflector on these is very obviously different than the previous sprinklers we've talked about. It's basically half of a deflector - but that's the point.

TY3331 Sidewall Fire SprinklerTY3351 Sidewall Fire Sprinkler

What about available temperatures? You can get them in the same 135 to 360 degree Fahrenheit range in either chrome, white, or brass.

Sprinkler Type 4: Concealed

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.

Below is a picture of the Tyco TY3531 concealed fire sprinkler. The bulb isn't as easy to see but this is a quick response sprinkler. Once a cover plate is installed, the deflector will be hidden, as shown in the next picture. Once the cover plate falls off at the specified temperature, the deflector is exposed and operates just like a pendent fire sprinkler would.

TY3531 Concealed Fire SprinklerTyco Concealed Pendent with Cover Plate RFII

Common temperatures associated with concealed fire sprinklers are 155 and 200 degrees Fahrenheit, though some higher temperatures are available. 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. Whatever you do, do not paint fire sprinkler cover plates.

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!

Add Comment