#396 – Viking’s Latest Thread-On Concealed Sprinkler Cover Plates

Viking’s newest concealed fire sprinkler cover plate threads into place

Viking launched a new thread-on cover plate for concealed fire sprinklers. These covers are designed for use with Viking’s existing line of Mirage, Freedom, and XT-1 concealed pendent sprinklers. Instead of pushing into place like Viking’s existing plates, these screw into place to give a tighter fit.

Viking’s catalog is focused and utilitarian—it’s bound to have just the part you need, but it won’t make you wade through any fluff to get it. And now, every type of cover plate—small or large diameter, square, extra-large orifice, etc.—has two installation options: thread-on or push-on.

Not everyone needs a thread-on cover plate for their concealed fire sprinklers. But for those who do, this is a big deal. Viking introduced the feature in response to feedback from customers who required tighter-fitting cover plates that wouldn’t dislodge from impacts and shaking. These new models are still easy to install and meet industry needs—they just give customers more choices.

Read on learn:

  • The specific differences between thread-on and push-on cover plates
  • How easy it is to install thread-on cover plates
  • What changes about buying Viking’s concealed fire sprinklers and cover plates

Check out our selection of Viking commercial and residential fire sprinklers, cover plates, installation tools, and our selection of push-on and thread-on cover plates that are specifically found in the Mirage line.

How the new thread-on Viking cover plates give a more secure fit

Viking has several main lines of concealed sprinklers: Mirage commercial concealed sprinklers, the Freedom line of residential sprinklers, and several models that are simply named by their sprinkler identification number (SIN), often with an extra digit, rather than a model name. Many of these newer sprinklers have features of the XT-1, Viking’s latest design, but may not be explicitly labeled XT-1s and can be direct replacements for older models. For example, the Mirage VK461 standard/quick response concealed sprinkler (2.8k) can be replaced with the VK4611 (note the extra “1”) standard/quick response concealed sprinkler (2.8k).

Previously, cover plates for Viking concealed sprinklers always had push-on installation. Basically, just pop the plate into place, and you’re done. So, physically, what’s the difference between a thread-on and a push-on cover plate?

First, here’s what’s the same. Viking’s new thread-on cover plates are the same size as the push-on plates, and both types work with the same sprinklers, no problem. Second, they have the same thermal sensitivity—the solder will melt at the designated temperature, just as you expect. Finally, the new cover plates install easily using the same cover plate tool from Viking. (Learn more about installation in the next section.)

The difference is in the tabs. Viking’s original cover plate models have push-on and thread-off installation. When pushed into place, six flexible brass tabs on the plate’s ring hold it in place in the sprinkler cup.

In the new thread-on model, four of the tabs are replaced with solid nubs that fit into the sprinkler cup’s threads.

Viking twist-on vs push-on covers
The difference between Viking’s push-on and thread-on cover plates is in the tabs. In the push-on version (top), six flexible tabs hold the cover plate in place in the sprinkler cup. The new thread-on version (bottom) replaces most tabs with solid nubs that thread into the sprinkler cup.

This change provides one significant benefit—a tighter fit. The concealed sprinkler cover plates fit more snugly into the fire sprinkler cup and won’t fall out easily. This is advantageous in situations where your sprinklers may be battered, bumped, shaken, or otherwise roughly treated. The tight fit saves you from replacing plates that fall out, possibly cutting down on labor and material costs in settings with many covers.

It’s important to note that the previous cover plates also have a pretty secure fit and work great in the vast majority of settings. But the tighter fit of the thread-ons might prevent cover plates from shaking loose:

  • In earthquake-prone areas
  • Where vehicles or heavy machinery cause lots of vibrations
  • In sports arenas like racquetball courts

Thread-on cover plates might also be preferable for cleanroom applications where staying dust-free is an absolute necessity. Concealed fire sprinklers with rubber gaskets between the plate and the ceiling prevent dust from accumulating on sprinklers. Thread-on caps can give that much more assurance that the gasket seal won’t fail in a broader range of circumstances.

Not everyone needs this thread-on feature. But for those that do, having the option is extremely useful.

Check out this article to learn more about Viking’s commercial sprinkler offerings.

Thread-on concealed sprinkler cover plate installation—the standard tool still works

Installing Viking’s new thread-on cover plate is simple and easy. It works with the same tools you use for a push-on version and only takes about one second longer.

To install a Viking concealed pendent sprinkler and thread-on cover plate, you’ll need:

  • A concealed sprinkler (like the commercial Mirage VK462 or the residential Freedom VK494) with a protective cap and thread-on cover plate
  • The appropriate sprinkler wrench
  • A cover plate installation tool (standard-size or large-diameter)
  • A length of PVC pipe if you need extra reach

How to install Viking cover plate

To install Viking’s thread-on cover plate:

  1. Use the sprinkler wrench to hook the protective cap. This can be done from the floor with the fire sprinkler wrench attached to a length of PVC.
  2. Pull the cap off the sprinkler.
  3. Put a cover plate in the cover plate installation tool (which can be attached to the opposite side of the PVC pole) and insert it into the concealed sprinkler cup.
  4. Push the cover plate into position and make a quarter-turn to the right. The cover is now installed.

Installing a thread-on plate is just as easy as installing a push-on plate—again, it only takes a second longer.  Check out this video that shows how to install these cover plates in Viking’s new VK4621 sprinklers, a model that can be installed without removing the protective cap:

Get the tools you need for your next job. Shop Viking standard-size and large-diameter cover plate installation tools, Viking sprinkler wrenches, and escutcheon installation/cap removal tools.

How to shop for Viking concealed pendent fire sprinklers and cover plates

The launch of these new thread-on cover plates does shake up the Viking catalog a little. But it’s still easy to get the concealed sprinklers and covers you need. That’s because there is now one thread-on alternative for every existing push-on cover plate—and every version of the cover fits existing sprinklers.

When you order covers for concealed sprinklers, you have multiple choices to make. First are the big-picture items—size, shape, construction, temperature sensitivity, and special applications. Viking has options for:

  • Large-diameter (3 5/16”) and small-diameter (2 3/4”) plates
  • Square and circular plates
  • Stainless steel plates
  • Plates for extra-large orifice (ELO) sprinklers
  • Plates for cleanroom applications

Now, when you choose from these options, you can also ask for either thread-on or push-on. To make it easy to get the right cover plate, Viking has 1) assigned a unique part number to the new thread-on covers and 2) given new part numbers to the existing cover plates.

Here’s a summary of the part number changes for some of the most frequently used Mirage cover plates:

Part Numbers for Viking Push-On and Thread-On Cover Plates

Cover Plate Description Push-On Thread-On
Old Part
New Part
Part Number
Small diameter 13504 23447 23190
Small diameter, stainless steel 21876 23455 23193
Large diameter 13642 23463 23174
Large diameter, stainless steel 21875 23473 23183
Square 15394 23482 23179
ELO 15765 15765 23495
ELO, stainless steel 21878 21878 23504

New thread-on concealed sprinkler cover plates for Viking give you more choices

Concealed fire sprinklers are great options when you want your sprinklers out of sight and out of mind. They also have the advantage of keeping the heads out of the way of potential impacts and tampering. But what about the concealed sprinkler cover plates installed in environments that are prone to vibration or impacts.

This is where the new option shines: 4 flexible tabs were replaced with nubs that fit into the threads of the cup, providing a more secure fit. Everything else is the same, so new thread-on plates work with sprinklers you already have—and so will the older push-on models.

Check out our selection of Viking cover plates, and contact us if you’d like to specify whether you want push-on or thread-on. And don’t forget to pick up sprinkler wrenches and cover plate installation tools.

As always, don’t hesitate to contact our customer service team if you don’t see the exact part number or feature you need. We’re happy to help you get it. 

This blog was originally posted at blog.qrfs.com. If this article helped you, check us out at Facebook.com/QuickResponseFireSupply or on Twitter @QuickResponseFS.



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