RPBA (Reduced Pressure Principle Backflow Prevention Assembly): Test Procedure using the MAKO MK5 5-Valve Test

Test Prep: Flush Test Cocks and Power on and Clear the MAKO MK5

1. NIIO means notifying the owner, identifying the backflow, inspecting the backflow, and observing the conditions of and around the assembly.
2. You then need to open and leave open the test cocks in the correct order, TC4 then TC3, then TC2 and then TC1.  To flush out any contamination that may be inside the Test cocks.
3. Then, in reverse order, shut off TC1, TC2, TC3, and TC4. Note: Attach any fittings needed to perform the test.  

4. Make sure the MAKO MK5 is turned on and that all values from previous tests have been cleared.  Hold down the Back button until the values clear.
5. Close all test kit needle valves and connect all hoses to the appropriate location on the MH5.  Be careful NOT to over-tighten the needle valves when you close them.     

Connect Hoses and Get the Apparent Value                                                             

1. Connect high side to test cock 2 (TC#2) and connect the low side to test cock 3 (TC#3).
2. Slowly open TC#3 Fully, then open the low bleed and leave open
3. Slowly open TC#2 Fully, then open the high bleed and leave open
4. Close #2 Shut Off valve
5. Close the high bleed valve, wait for MK5 psid to stabilize,  and then slowly close the low bleed valve.
   1. If the relief valve does not open, make a mental note of the value you read on the screen, this will be the Apparent Differential pressure across Check Valve #1,        DO NOT press the record/Capture button.

Test the Relief Valve:  Record the Differential Pressure Reading at the Moment the Relief Valve Opens.

1. Open High side control valve one full turn.
2.  Slowly open the Low side control valve no more than ¼ turn. Note I would barely crack open the Low side control valve, on some devices it can drop fast and you need to be ready to hit the Record/Capture button fast enough.
3. When the relief valve opening is detected, immediately press the Record/Capture button.
4. Close the Low side control valve, Maintain the #2 Shutoff valve closed and the High side control valve to stay open.                                                                                  

Test the #2 Check Valve for Tightness

1.  Open the Bypass control valve to remove air from the bypass hose and then close the Bypass control valve.
2.  Attach the bypass hose to TC#4 and then fully open TC#4.
3.  Open the Low bleed valve until the reading on the MK5 reads above the apparent differential pressure across the number one check valve.  
4.  Slowly close the Low bleed valve.  
5.  Open the Bypass control valve and wait for the pressure to stabilize.
6.  You will either record the #2 Check valve is closed tight or that it leaked and the relief valve opened.                                                                                                 

Test and Record the Differential Pressure Across #1 Check Valve

1. Testing the #1 Check valve: The pressure must be greater than the relief valve opening point reading and at least 5.0 psi.
2.  With everything still connected and the High and Bypass control valves still open
3. Open the low side bleed until the reading exceeds the apparent value you made a mental note of earlier.
4. Slowly close the Low bleed valve.
5. Once the reading stabilizes, record the psid reading by pressing Record/Capture button….as the reading across Check Valve #1                                               

Optional: Record the Line Pressure

1. If you are going to record the line pressure: Close TC4 and TC3 and open low bleed valve.  When satisfied with the reading record the line psid reading by pressing the Record/Capture button.

Close up and clean up, remove test equipment, and return the backflow device to service.  

1. Close all the test cocks.  Remove all the test equipment.  Make sure you remove your test fittings.
2. Slowly open #2 Shutoff being careful not to hammer your customer water lines.
3. Open all the Mako MK5 valves and drain water from the Mako MK5.
4. Notify owner/customer
5. Do your report and send it in. With the Arbiter App you could email the report.

The Arbiter Backflow Test Kit

If you’re serious about backflow testing, the Arbiter Backflow Mako MK5 Digital 5-Valve Backflow Test Kit is the game-changer your toolkit has been missing. This is not just another backflow tester—it’s an all-in-one solution designed to streamline your workflow and boost your professional credibility. What sets the Mako MK5 apart is its seamless integration with Mako Assist software, which automates paperwork and eliminates the time-consuming process of manual data entry. With built-in location mapping, the software automatically records your GPS coordinates, ensuring your tests are accurately logged for compliance. Imagine wrapping up a job site visit and having all your test reports auto-generated and ready for submission—no more messy forms or risk of human error.

But that’s not all. The Arbiter Mako MK5 comes with a soft case and high-quality hoses, making it the perfect mobile solution for fieldwork. This digital kit is built to last, combining precision testing with a modern interface that’s easy to use even for those who are less tech-savvy. The automation of reporting not only saves you hours each week but also adds a stamp of credibility to your business—clients can trust that your testing is backed by precise, state-of-the-art technology. If you’re ready to elevate your backflow testing game, the Mako MK5 is the ultimate investment in efficiency, reliability, and professionalism.

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