Backflow Prevention & RPZ Testing Requirements

ISO Accredited RPZ Testing for Backflow Prevention

Is your sprinkler system equipped to pass the backflow prevention testing requirements? Did you know that state laws require backflow testers or reduced pressure zone (RPZ) testers to be verified on an annual basis? An RPZ must be tested by a certified backflow assembly tester with the properly calibrated equipment at the time of installation and once per year. With the introduction of warmer weather, now is the time to schedule your RPZ test to comply with the Department of Health and State Plumbing Codes.

What is Backflow?

Backflow can occur when there is a cross-connection or back pressure, causing water from the home to enter the drinking water supply. This contamination could pose potential health problems. According to the American Backflow Prevention Association (ABPA), “each water supplier should ensure that a proper backflow preventer is installed and maintained at the water service connection to each system or premises that poses a significant hazard to the public water system.”

Plumbers, contractors and building maintenance workers use RPZ testers to measure the differential pressure or pressure difference between two points. A backflow prevention device is used to prevent chemicals or pesticides from entering the water system and causing contamination.

backflow prevention tester

3 Valve and 5 Valve RPZ Testers

The two most common types of RPZ testers are a 3 valve RPZ and a 5 valve RPZ. The 5 valve RPZ test generally saves time as the testing procedure can be completed without disconnecting any hoses. A 5 valve RPZ also offers more flexibility. The most common brands of RPZ testers are Watts, Mid-West Instruments and Wilkins. Contractors and plumbers alike have seen success using all of these devices and brands of RPZ testers.

RPZ or Backflow Tester Calibration

Backflow preventer or RPZ tester calibration is recommended on an annual basis and by an accredited entity. Many companies who provide this calibration only test the gauge on an RPZ tester. This does not account for leaks or other problems that could occur with the valves. The plumbers or contractors have no way of knowing this until they perform the test and find that one of the valves is leaking.

PMC is one of the few companies that test the entire RPZ assembly. PMC is an ISO/ IEC 17025 accredited calibration lab that has certified, repaired and calibrated this equipment for 15+ years. In addition, PMC has access to the Watts parts for easy replacement and repair of the backflow prevention tester. PMC tests the RPZ tester up to 115 psi. It is important to note that the recommended water pressure depends on type of building.

Who is Responsible for Backflow Prevention /RPZ Testing?

RPZ tester

The Department of Health made it a requirement that all water systems that use water for a non-potable use have an approved backflow assembly. This includes:

  • Public water supplies
  • Commercial owners
  • Residential property owners

To help contractors, municipalities and owners understand the requirements and responsibilities of RPZ or backflow protection installation and testing, the Minnesota Department of Labor & Industry developed a quick fact sheet about this code.  Included within this sheet are the responsibilities of the plumber, municipality and owner.

Schedule Your RPZ Tester Calibration Today

While it may seem like a daunting task to calibrate your equipment before performing an annual backflow test, PMC can help. RPZ tester calibration is available on a first-come, first-serve basis. Call ahead to ensure your equipment is properly calibrated before performing your annual test. Customers are also welcome to send-in or drop-off their equipment at one of our four locations across the Midwest. Find a location near you – here.

Call PMC at (800) 328-1235 to schedule your calibration. For more information about these requirements, or if you’d like to schedule your backflow prevention test, contact us today.

Schedule Your RPZ Tester Calibration


2019-11-22T14:52:56-06:00May 9th, 2019|