The singular piece of equipment used to perform backflow prevention assembly testing is the Backflow Preventer Test Kit.  It makes complete sense that the care and maintenance of your test kit is vitally important to conducting field tests and getting accurate results.  So, let’s break down the basics of the Backflow Preventer Test Kit and get a better understanding of the importance of this piece of equipment. 


What is a Backflow Preventer Test Kit? 

The Backflow Preventer Test Kit is a compact portable device that measures differential pressure and is used for all testing of backflow prevention assemblies, i.e. DCVA, RP, PVB and SVB types.  Depending on the model, test kits come equipped with either 3 or 5 soft seated needle valves.  Equipped with a full-face scale, the kit can measure a range of 0-15 psid (psi differential).  Most models also come equipped with 0-200 psi service line pressure gauge.  Test kits are equipped with three color-coded service hoses with inline filters for connecting the test kit to the backflow prevention assembly.  And finally, all test kits should have a rugged, durable carrying case for storage protection when not in use. 


How accurate are Backflow Preventer Test Kits and should they be verified for accuracy? 

Backflow Preventer Test Kits are designed and manufactured to be accurate within +/- 1% of full scale or +/- .2 psid and all test kits should be verified for accuracy prior to starting service.  All manufacturers recommend and most states require that your test kits be certified for accuracy on an annual basis.  If the test kit falls outside of the parameters of accuracy, a calibration or repairs may be necessary to ensure accuracy of the test kit. 


Why should my Backflow Preventer Test Kit be checked annually for accuracy? 

The accuracy of your test kit is dependent on many factors that can cause it to not be as accurate as needed. Test kits can fall as much as 1 to 2 psid out of range if not cared for and that would make the difference in passing or failing a backflow prevention test.  Even small inaccuracies could be critical to the test results.  Factors that could impair the accuracy of your test kit include the following: 

  • Improperly securing your test kit during transport.  Allowing a test kit to roll around unsecured in your vehicle can severely impact the accuracy of the test kit. 
  • Similarly, not securing your test kit onsite can cause the same types of issues.  Allowing a test kit to bump every pipe in a mechanical room or bang your ladder as you’re climbing up to perform your test will have an impact on the test kit. 
  • If you perform a lot of backflow tests, the normal wear and tear, creating internal friction, can cause seats to become worn and the diaphragm expanded, resulting in a loss of accuracy. 
  • Conversely, not using your test kit enough may cause issues with accuracy.  The test kit could dry out and the internal components could become brittle, resulting in a loss of accuracy. 
  • Not draining your test kit after every use is another major issue that can cause accuracy concerns.  Depending on external temperatures, the water left in a test kit can expand if in a hot climate and possibly freeze if left in cold temperatures.  Both of these situations can cause significant harm to the test kit and result in a loss of accuracy. 


The bottom line is simple.  If you take care of your backflow test kit, it will take care of you.  Through proper handling, maintenance and annual verification, your test kit will perform accurately and flawlessly, resulting in the kind of backflow test results necessary to do your job.