Viking’s selection of commercial fire sprinklers covers a range of applications and features

It’s easy to get overwhelmed while shopping for fire sprinklers. The choices seem endless, yet the differences between individual models may appear minuscule. In truth, there are some clear choices for specific applications. In a series of blog posts, we’re taking a detailed look at the offerings of major sprinkler manufacturers, so that you can understand the features each of them offers. This piece explains Viking sprinkler heads, examining factors like:

  • Orientation
  • Thread Size
  • K-factor—the rate of water discharge
  • Response speed—standard response (SR) or quick response (QR)
  • Coverage area—standard coverage (SC) or extended coverage (EC)
  • Temperature rating
  • Finishes, both cosmetic and functional

Viking’s founder Emil Tyden entered the fire sprinkler business in 1920 when a fire destroyed the factory for his International Seal and Lock Company. One hundred years later, his company is a leader in the fire protection industry.

Viking has three core lines of commercial fire sprinklers that we’ll cover in this article:

  • Model M
  • XT1
  • Mirage

Note that Viking does make numerous other sprinklers beyond what we cover here. For instance, the company also manufactures a range of dry barrel, deluge, and preaction sprinkler heads, which are beyond the scope of this article.

Before we get into the details, here’s a quick summary of the Model M, XT1, and Mirage sprinkler heads:

The Model M line

  • A relatively small sprinkler
  • Two varieties: Micromatic and Microfast
  • Micromatic is standard response, Microfast is quick response
  • Standard coverage and extended coverage are available
  • Stainless steel construction is available in some models
  • Cosmetic and corrosion-resistant finishes are available

Next-generation XT1 sprinklers

  • Small—smaller even than the Model M line
  • Corrosion-resistant stainless steel construction comes standard
  • Standard and quick response options
  • Standard coverage only
  • Cosmetic and corrosion-resistant finishes available

Mirage concealed pendent sprinklers

  • Concealed pendent sprinklers paired with cosmetic cover plates
  • Standard and quick response are available
  • Standard and extended coverage are available
  • Corrosion-resistant finishes are available for the sprinkler assembly

Now, let’s take a closer look at each line:

Model M Viking fire sprinkler heads

The Model M line of sprinklers was, at its introduction, notable for its compact size. This is reflected in the names of its two varieties: the Micromatic and the Microfast.

Microfast sprinklers, fittingly, are quick response (QR) sprinklers—those with a primary mission of quickly activating to protect people by enabling them to escape during a fire. Micromatics are standard response (SR) sprinklers, which focus on containing the fire in its original location and suppressing its growth.

Learn more about standard vs. quick response sprinklers here.

Most Model M sprinklers use a temperature-sensitive glass bulb, but some feature a meltable fusible link.

Viking M sprinklers

Viking's Model M sprinklers feature a compact design and basically all of the features you might need—quick or standard response, extended or standard coverage, corrosion-resistant finishes, and more.

Model M K-factor and pipe thread size

Both the Micromatic and the Microfast varieties come in upright, pendent, and sidewall orientations. In any orientation, they are available with 1/2" and 3/4” National Pipe Thread (NPT).

The two most widely-available K-factors—the rate at which water discharges—for Model M sprinklers are the 5.6 and 8.0 industry mainstays. The only exceptions to this are some of the extended coverage sprinklers with extra-large orifices. These have a K-factor of 11.2 or more. And some of the high-pressure sprinklers have a low K of 2.8.

Model M sprinklers come in standard or extended coverage

Importantly, Model M sprinklers are the only non-concealed Viking sprinklers available with extended coverage. Extended coverage sprinklers, where they are feasible and allowed by National Fire Protection Association (NFPA) standards and local codes, offer some system cost savings over standard coverage sprinklers. But their use has become less common in the US, as some codes do not allow them, they require expert knowledge of minimum operating pressures, and they must be installed in a "smooth, flat ceiling."

The option for extended coverage gives the Model M line a unique feature, even though Viking has more modern sprinklers available.

Temperature, finish, and construction options for Model M sprinklers

Viking offers a wide range of temperature ratings for their Model M sprinklers, including 155F, 175F, 200F, 286F, and 360F. The highest of these ratings are not available in some finishes, namely, with a wax coating or Nickel PTFE (ENT).

Model M sprinklers are available in unfinished brass or with chrome, white polyester, black polyester, and nickel PTFE (ENT) finishes. Polyester paint and ENT finishes provide corrosion resistance. Wax coatings, which also confer corrosion resistance, are also sometimes available either over brass or over polyester paint.

And a few Model M sprinklers are available with solid stainless-steel construction instead of brass.

Find the Model M Micromatic sprinklers with the features you need from these tables:

Model M Micromatic Conventional and Upright Sprinklers

SINLink/bulbOrientationSC/ECSR/QRThread SizeK-factorNotes
VK100BulbUprightSCSR1/2"5.6Ultra-high-temp available
VK124BulbUprightSCSR1/2"5.6High-pressure 250PSI
VK130BulbUprightSCSR1/2"5.6Stainless steel construction
VK200BulbUprightSCSR3/4"8Ultra-high-temp available
VK200BulbUprightSCSR1/2"8Replacement only
VK204LinkUprightSCSR1/2"8Replacement only

Model M Micromatic Pendent Sprinklers

SINLink/bulbOrientationSC/ECSR/QRThread SizeK-factorNotes
VK102BulbPendentSCSR1/2"5.6Ultra-high-temp available
VK122BulbPendentSCSR1/2"5.6High-pressure 250PSI
VK132BulbPendentSCSR1/2"5.6Stainless steel construction
VK202BulbPendentSCSR3/4"8Ultra-high-temp available
VK202BulbPendentSCSR1/2"8Replacement only
VK206LinkPendentSCSR1/2"8Replacement only
VK368LinkPendentSCSR3/4"8Stainless steel construction

Model M Micromatic Sidewall Sprinklers

SINLink/bulbOrientationSC/ECSR/QRThread SizeK-factorNotes
VK104BulbHor. SidewallSCSR1/2"5.6
VK106BulbVert. SidewallSCSR1/2"5.6
Viking VK sprinklers

The VK104 sidewall Model M Micromatic features standard response and standard coverage with a horizontal sidewall deflector. Its nominal temperature ratings range from 135F to 360F. Besides the pictured finishes (from left to right, brass, chrome, and white polyester), it is also available in corrosion-resistant black polyester, black PTFE, and wax-over-brass and wax-over-polyester.

Find the Model M Microfast sprinklers you need with these tables:

Model M Microfast Conventional and Upright Sprinklers

SINLink/bulbOrientationSC/ECSR/QRThread SizeK-factorNotes
VK315BulbUprightSCQR1/2"5.6High Pressure
VK316LinkUprightSCQR1/2"5.6High Pressure
VK338BulbUprightSCQR1/2"5.6Stainless steel
VK350BulbUprightSCQR1/2"8Replacement only
VK352BulbUprightECSR/QR3/4"11.2Extra-large orifice

Model M Microfast Pendent Sprinklers

SINLink/bulbOrientationSC/ECSR/QRThread SizeK-factorNotes
vk339BulbPendentSCQR1/2"5.6Stainless steel
VK352BulbPendentSCQR1/2"8Replacement only
VK534BulbPendentECSR/QR3/4"11.2Extra-large orifice
VK610BulbPendentECSR/QR1/2"5.6High Pressure
VK611LinkPendentECQR1/2"5.6High Pressure

Model M Microfast Sidewall Sprinklers

SINLink/bulbOrientationSC/ECSR/QRThread SizeK-factorNotes
VK305BulbHor. SidewallSCQR1/2"5.6
VK306BulbVert. SidewallSCQR1/2"5.6
VK307LinkHor. SidewallSCQR1/2"5.6
VK309LinkVert. SidewallSCQR1/2"5.6
VK319BulbHor. SidewallSCQR1/2"5.6High-pressure
VK320LinkHor. SidewallSCQR1/2"5.6High-pressure
VK333BulbHor. SidewallSCQR1/2"2.8
VK334LinkHor. SidewallSCQR1/2"2.8
VK344BulbHor. SidewallSCQR1/2"2.8High-pressure
VK346LinkHor. SidewallSCQR1/2"2.8High-pressure
VK360BulbHor. SidewallSCQR3/4"8
VK605BulbHor. SidewallECSR/QR1/2"5.6
VK609LinkHor. SidewallECQR1/2"5.6
VK612BulbHor. SidewallECSR/QR1/2"5.6High-pressure
VK613LinkHor. SidewallECQR1/2"5.6High-pressure
Viking VK305 Sprinkler

The horizontal sidewall VK305, a Model M Microfast sprinkler, features a quick-response bulb (note how thin the bulb is) and standard coverage. Besides the pictured chrome finish, it also comes in corrosion-resistant black polyester, white polyester, and electroless nickel (ENT) finishes.

Viking’s XT1—the next generation of fire sprinkler heads

While they provide some unique, useful features, the Model M is somewhat of a legacy line. They are superseded by the XT1 line of sprinklers, hailed by Viking as the “next generation of fire sprinklers.”

XT1 sprinklers are small—smaller than the “micro” Model M’s. For example, the VK102 Micromatic sprinkler has an overall length of 2-1/4”, while the XT1 that follows it, VK1021, is only 1-15/16” long. They are easy to install, and they all resist corrosion, coming standard with stainless steel deflectors and arms.

XT1 sprinklers are available in all orientations—pendent, upright, and sidewall—and in quick response and standard response varieties. All XT1 sprinklers feature a temperature-sensitive glass bulb.

Viking XT1 Sprinklers

Viking’s XT1 sprinklers, the next generation of fire sprinklers, are compact and feature standard stainless-steel construction for corrosion resistance.

XT1 K-factor and pipe thread size

Viking manufactures XT1 fire sprinklers in 1/2" and 3/4" NPT sizes and with a K-factor of 5.6 or 8.0. Almost without fail, 1/2" NPT sprinklers have K=5.6, and 3/4" NPT sprinklers have K=8.0. The only exceptions are VK2002 and VK2022, replacement-only parts with 1/2" NPT and K=8.0. Note that this thread size and flow rate combination is not approved for new installations, only replacements.

XT1 sprinklers offer standard coverage

XT1 sprinklers are not available with extended coverage—only standard coverage. Again, this is due to the less-common use of extended coverage sprinklers in modern systems (especially in the US), and the fact that some local codes do not permit their use.

Temperature and finish options for Model M sprinklers

Viking offers a wide range of nominal temperature ratings for its XT1 sprinklers, including 155F, 175F, 200F, 286F, and 360F. The highest of these ratings is not available for nickel PTFE (ENT)-coated models.

XT1 sprinklers can be ordered with a range of cosmetic and functional finishes, including brass, chrome, white polyester, black polyester, and nickel PTFE (ENT). White and black paint and nickel PTFE provide corrosion resistance.

Viking’s XT1 sprinklers are the next generation of fire sprinkler heads. Shop for upright and pendent XT1 sprinklers plus accessories on our website. Don’t see what you need? Contact us, and we'll get it for you.

Choose the right XT1 sprinkler head for your needs by using these tables:

XT1 Pendent Sprinklers

SINLink/bulbOrientationSC/ECSR/QRThread SizeK-factorNotes
VK1021BulbPendentSCSR1/2"5.6High-pressure 250PSI
VK2022BulbPendentSCSR1/2"8Replacement only
VK3021BulbPendentSCQR1/2"5.6High-pressure 250PSI
VK3522BulbPendentSCQR1/2"8Replacement only

XT1 Upright Sprinklers

SINLink/bulbOrientationSC/ECSR/QRThread SizeK-factorNotes
VK1001BulbUprightSCSR1/2"5.6High-pressure 250PSI
VK2002BulbUprightSCSR1/2"8Replacement only
VK3001BulbUprightSCQR1/2"5.6High-pressure 250PSI
VK3502BulbUprightSCQR1/2"8Replacement only
Viking XT1 models side by side

Both parts of the XT1 series—the VK1021 (left) and VK3021 (right) pendent sprinklers—come in standard coverage. The VK1021 is standard response and thus has a thicker bulb than the quick-response VK3021. The XT1 series is compact, measuring only 1-15/16” in length. Besides the pictured brass finish, these (along with all XT1 sprinklers) can be purchased in chrome, white polyester, black polyester, and electroless nickel (ENT) finishes. Polyester and ENT finishes provide corrosion resistance.

Mirage concealed pendent fire sprinkler heads

Viking’s Mirage concealed pendent fire sprinklers, when paired with cosmetic heat-sensitive cover plates, let you maintain the appearance of a smooth ceiling. Mirage sprinklers can be purchased with standard response or quick response. All Mirage sprinklers feature a heat-sensitive glass bulb, as well as a heat-sensitive cover plate assembly.

Viking Mirage sprinkler and cover plate

Mirage concealed pendent sprinklers, like the VK462 shown to the left, combine aesthetics with functionality. They are paired with a decorative drop-away cover plate like the brushed copper plate finish on the right.

K-factor and thread size for Mirage sprinklers

Mirage concealed fire sprinklers have threads in 1/2" and 3/4” NPT sizes. When it comes to water flow, Mirage sprinklers have a range of K-factors2.8, 4.2, 5.6, 8.0, and 11.2 are all available.

Mirage fire sprinklers come in standard and extended coverage, plus specialty applications

Mirage models are available with standard or extended coverage. Viking also offers Mirage concealed sprinklers and cover plates specifically designed without ferrous materials so that they are suitable for MRI rooms. Magnetic resonance imaging (MRI) devices are used for medical applications and feature extremely powerful magnets. MRI rooms must be free of all ferrous material for safety reasons.

Temperature response options for Mirage sprinklers

Mirage sprinklers, like all concealed pendents with cover plates, actually have two temperature ratings—the activation temperature for the sprinkler head and the drop-away temperature for the cover plate. The temperature at which the plate falls away must, naturally, be sufficiently lower than the temperature at which the sprinkler activates.

The following temperature combinations are available:

  • 155F sprinkler/135F plate
  • 175F sprinkler/165F plate
  • 200F sprinkler /165F plate

Cosmetic options for Mirage concealed sprinklers and cover plates

The actual sprinkler heads for Mirage concealed head systems only come in two colors—brass and electroless nickel (the latter for corrosion resistance). However, Viking offers cover plates in:

  • Polished chrome
  • White
  • Ivory
  • Black
  • Bright Brass
  • Brushed Brass
  • Antique Brass
  • Brushed Copper
  • Brushed Chrome

Moreover, Viking will provide custom-designed cover plates on request. QRFS suggests printing an image of a fire sprinkler on the cover plate. Learn more about matching cover plates to sprinklers and why you shouldn't paint your cover plates in our previous blogs.

Shop a rich selection of cover plates for Viking Mirage concealed pendent sprinklers on our website. If you want to order a Mirage sprinkler or a custom cover plate—or can’t find the sprinkler you need— contact us.

Pick the right Mirage concealed pendent sprinkler for your needs by using this table:

Mirage Concealed Pendent Sprinklers

SINLink/bulbOrientationSC/ECSR/QRThread SizeK-factorNotes
VK462-MRIBulbPendentSCQR1/2"5.6For MRI rooms
VK464-MRIBulbPendentSCQR3/4"8For MRI rooms
VK469LinkPendentSCQR3/4"11.2Extra-large orifice
vk538LinkPendentECQR3/4"11.2Extra-large orifice, ordinary hazard
VK636LinkPendentECQR3/4"11.2Extra-large orifice, light hazard

Viking’s commercial fire sprinkler heads fill generalist or specialized roles

Viking’s Model M, XT1, and Mirage sprinkler heads suit a variety of applications. Need extended coverage, high pressure, high K-factor, or quick response? Odds are that a Model M sprinkler will get the job done. Looking for a compact, easy-to-install sprinkler for a corrosive environment—or, really, most applications? The XT1 is the most modern choice. Need a concealed head sprinkler with extended coverage and a cover plate that matches the background? A Mirage concealed pendent with a custom cover plate is just the thing.

With a wide selection of temperature responses, response speeds, coverage areas, K-factors, cosmetic and utilitarian finishes, and more, Viking’s selection of sprinklers can hit just about any requirement.

Get the sprinklers you need by shopping our selection of Viking commercial sprinklers. Don’t forget Viking escutcheons, cover plates, and installation tools to finish the job. And if you don’t find what you need, reach out to us, and we'll help you get it.

Call us at +1 (888) 361-6662 or email [email protected].

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