For many years I have heard complaints from testers questioning why there is not a single set of “National” test procedures for testing backflow prevention assemblies.  There are numerous national and regional trade associations and universities engaged in promoting cross-connection control and backflow prevention. For this article they will be referred to as organizations. Some of these organizations are also involved in training and/or certification of backflow prevention assembly testers. One thing they have in common is that they do not agree on how to test a backflow prevention assembly!

The Backflow Prevention Manufacturers Association (BPMA) has lobbied several of these organizations to work together and create a single test procedure for each assembly. They even suggested bringing a shredder and symbolically eliminating all test procedures and start from scratch to develop a single procedure. The feedback included words to the effect “we’ll go in a lab and prove that ours is the best” which led to “we’ll prove that ours is better than yours in the lab” or “we’ll prove that our procedure is capable of testing the assembly in the lab.”  No effort was made to answer the question “What is the proper way to test an assembly?”  The result was the organizations agreed to disagree.

For this article I will be questioning the test procedures for Reduced Pressure Assemblies (RP Assembly) and Double Check Valve Assemblies (DC Assembly) in North America. One organization opposes closing the number one shut off valve when testing and RP Assembly as it may knock debris loose fouling the assembly. That same organization promotes closing the number one shut off valve and performing a one hose test on a DC Assembly. Another organization promotes closing the number one shut off valve and performing a one hose test on an RP assembly while promoting leaving the number one shut off valve open and using a two-hose test procedure on a DC assembly.  Does this make any sense?  Add in the many other organizations that have their subtleties or idiosyncrasies and we are left with more test procedures than there are components to test in an assembly.  In some cases, the differences are not even regional, and the accepted test procedure can vary from county to county.  No wonder testers are frustrated.

I am not a plumber or certified tester with real in field-testing experience. I am an engineer whose testing experience is limited to training schools where the assemblies are small and at waist height. I do understand the hydraulics of backflow, how assemblies are designed to protect against backpressure and back siphonage and how to design and build a test kit to test them.  While I may need help from more experienced professionals to get the answers, I can certainly ask some questions.

• When a backflow event occurs are the RP and DC Assemblies supposed to function at the system pressure at which they are installed or is the system pressure reduced to atmospheric pressure downstream of the components prior to the backflow event? Should the Assembly be tested at the system pressure at which it is installed?
• Is the water downstream of the second check valve assembly non-potable? Should the test cock bleeding procedure be to first open test cock 4 to flow the potable water through the assembly flushing the non-potable water between the second check valve and number two shut off valve out of test cock 4 before attaching a potable test kit? How should the other 3 test cocks be bled?  When is the appropriate time to close the number 2 shut off valve?
• Should we first check if there is backpressure present on an assembly before proceeding with testing?
• When a backflow event occurs does the RP relief valve get forewarned to exercise itself before the backflow conditions occur? When should the relief valve be tested in relation to the other components of the RP assembly?
• Should we test the RP relief valve for the first drip only or should we then open the test kit valves to at least make sure the relief valve continues to open further? Should we confirm if the relief valve fully opens?
• Is the second check valve on an RP Assembly and the check valves on a DC Assembly supposed to be leak tight against backpressure? Is direction of flow testing relevant?  If some backpressure could cause a leaky check valve to seal, could full system back pressure cause a valve on the verge of failing to fail while the tester is present?  Should these check valves be tested at full system backpressure and then at a low backpressure, for example 1 PSID?
• Should the number 1 shut off valve be tested for operation? Does closing the number 1 shut off valve pose too much risk in fouling the assembly?  If the number 1 shut off valve is never tested for operation, what is the risk of not being able to close it if a large RP Assembly goes into full dump?
• If these organizations cannot agree on how the test assemblies with 4 or 5 components, why should the EPA or politicians take cross-connection control and backflow prevention seriously?

I am active in many of the organizations in the cross-connection control and backflow prevention industry.  All of them have the same issue, “how can we get more members?”, “how can we add value to our members and attract more?” Our potential members are asking for a single set of National test procedures (Oh and a set of National test report forms!). It is time we worked together to provide this value. A single set of test procedures, free for everyone to use, downloadable from multiple websites.

While it may be impossible to make a perfect set of test procedures, I am confident that if we gathered professionals from across all of North America we could develop one set of National test procedures that would be better than the many we have today.  While it will not be easy, it should be possible if we all check our egos at the door. If we focus on what each component in an assembly does to prevent backflow in the real world, we should be able to agree on the best way to test each component to ensure that it is preventing backflow.

To quote a famous line from an infamous movie… “Who’s with me?”

Sincerely,

Mike Lueck, Mid-West® Instrument

About the Author

Mike Lueck is president of Mid-West® Instrument, one of the leading designers and manufacturers of differential pressure gauges and switches in the U.S. Lueck has been active in cross-connection control and backflow prevention through involvement with ABPA, ASSE, BPMA, the UA, and the State of Michigan since 1984, and is a current member of the ASSE Cross-Connection Control Technical Committee. Lueck earned his Bachelor of Science in Mechanical Engineering from the University of Michigan in 1982.