3 Tips for Checking a Deringer 1st Check Assembly

Backflow prevention systems are crucial to sanitary and potable water supplies. The only thing more essential than the systems is the maintenance and repair required to keep them functioning optimally. Backflow preventers are intricate systems with numerous parts that work together for a common purpose. One of those parts is called a first check assembly.

Like everything else we work with, check assemblies need to be examined, maintained, and sometimes replaced. Explore the process for checking the first check assembly in backflow systems. Moreover, learn about what to do if repair or replacement is required.

#1 Show Up With the Right Tools

Before you can even approach examining a check assembly, you must ensure you have the right tools for the job. You’ll be able to quickly tell if a particular job requires special tools or equipment. But, generally speaking, we recommend you bring the following things:

  • #2 Philips-head screwdriver
  • #2 flathead screwdriver 
  • 5/8" Ratchet wrench
  • Adjustable wrench
  • Deringer Test Cock Wrench
  • Slip-Joint Pliers
  • T45 Torx bit or key 
  • Wooden blocks: 2" x 4" x 5" and 1" x 2" x 16"

You will need all of these things to perform an adequate inspection. The screwdrivers and Torx bit are the most important items. They’ll help you disassemble the system to access the check assembly and reassemble it later.

#2 Check for Debris

Before you can examine the check for debris, you need to remove the check assembly from the backflow system. See full instructions here. We’ll summarize the steps below.

The first step is always to close the shut-off valves. Then, open the test cocks. Loosen the bolts on the access port cover plate and remove the cover plate. From there, loosen the check retainer bolts on both sides of the valve body. Gently push the first check module with your flathead screwdriver until you can easily remove the check by hand.

Now you can examine the first check.

Use your Phillips head to remove the tower screws; then examine the elastomer disk and check seat for fouling or damage. If debris is found, you can clear it from the check disc by simply wiping it off with water and a rag. If no damage is present, reassemble the check and reinstall it into the valve body of your backflow system. If not, you will need to remove and replace it.

#3 In Case of Damage, Check the Discs

If you find that the issue with your check assembly goes beyond debris buildup, it’s likely due for replacement. Thus, if you find any indication of damage to any part of the check assembly, it’s best to order the proper backflow preventer parts to perform the replacement.

Then, you’d repeat the disassembly process and replace the damaged parts with your new ones. Backflow Direct has you covered if you’re a backflow prevention professional and need parts, tools, or resources, so give us a call.  

For full instructions, visit BackflowDirect.com, and navigate to your Deringer model. You can find maintenance instructions, videos, and other procedures in the Literature Download Section.