“Here is an improper installation with multiple deficiencies.”
1) System has an unprotected bypass, this is not allowed.
2) Backflow assembly is not mounted per manufactures written specifications; mounting bracket blocks the ability to repair this assembly.
3) The Wye strainer is installed downstream of the backflow preventer. In order for the Wye strainer to perform its job and prevent debris from impeding check valve operation it must be installed upstream of the backflow preventer per manufacturer’s written instructions.
4) Both check valves leaked on this DCVA because the internal assembly was filled with gravel, the contractor did not follow manufacturers written installation instructions and flush the lines before installing the backflow preventer.
It’s important to note: if the Wye strainer was properly installed upstream of the backflow preventer per manufacturer’s suggestion, it would have blocked the gravel from entering the assembly and jamming the check valves in the fully open position consequently leaving the city water supply unprotected.
Below is off of Watts basic installation instructions found on the 774 series:
Check with local authorities for installation requirements. Install valve in the line with arrow on valve body pointing in the direction of flow. Pipe lines should be thoroughly flushed to remove foreign material before installing the unit. A strainer should be installed as shown, ahead of the backflow preventer to prevent discs from unnecessary fouling.
CAUTION: Do not install a strainer when backflow preventer is used on seldom-used water lines which are called upon during emergencies, such as fire sprinkler lines, etc.
This is an example of why it’s very important to “IDENTIFY” and “INSPECT” every assembly.
I sent an unmarked copy of this photo to several colleagues of mine and I asked them what they saw. They all assumed the last backflow tester failed to restore service to this existing assembly on a residential fire sprinkler system.
The problem is they are only looking at the backflow shut off valves #1 & #2. They failed to see that the fire sprinklers “Inspectors test/drain valve is in the open position,” and the “sprinkler system pressure gauge shows 0 psi.”
I do not know why the backflow assembly shut off valves are in the closed position and the inspector test valve is in the open position on this occupied residential property. What I do know is, if I restore service to this fire sprinkler system I will cause the alarm to sound and may cause property damage.
All I can do is return the system to the way I found it after I completed the test, then notify the owner of the situation, as well as inform the water department using the comments section on my test report.
Remember your USC training: NOTIFY, IDENTIFY, INSPECT, and OBSERVE.
Pics 1 through 3:
Here’s one for the good bad and the ugly. This is a 350ADA which the installer had converted to a Frankenstein RPBA/DCDA? I don’t know what you’d call this thing.
It was installed in 2013 and the CCS at the water district inspected the assembly at that time, but because the vault is small the relief valve went unnoticed.
The 1st tester tested it is a double check and got acceptable values in 2013. In 2014 I tested it as a double check and got good values. This year I go to test the assembly and suddenly my feet get soaked. I bend down and discovered the relief valve. The relief valve must have been stuck closed for the 1st two testing sessions.
I immediately put the system back online and went to see the CCS at the water Department. I explained what had happened and he was pretty surprised as he also initially inspected the assembly. I asked him if I can legally return the assembly to factory specifications? Because it still had the factory DC check modules installed it would only require a bulkhead assembly, cover plate, etc. Of course the CCS told me that it did have to go back to factory specifications.
I wanted to know why the relief valve did not vent for two different testers with 2 different companies for the 1st two years.
Turns out someone had stuffed paper in the relief valve stem to keep it forced closed. Over time the paper must have compress and degraded, this explains why the relief valve did not dump normally when it finally did open. Obviously it could not open fully.
Click on photos to enlarge
I have just restored service for this improperly installed irrigation backflow assembly. This is a 1″ Wilkins 975XL RPBA which is installed below ground with no daylight drain. When this backflow assembly fails the box may fill with water and create a potential indirect crossconnection.
As a backflow assembly tester it is important to note this on your test report to relieve yourself of any liability. Click photo to enlarge
This is an unapproved modification to a backflow assembly for a commercial tanker fill station.
The equipment circled in this photograph should have been installed downstream of shutoff valve #2 where the arrow is pointing. Currently the device is installed between test cock #3 and test cock #4.
This backflow assembly failed the backflow test; however there is no way of knowing if this assembly is failing because of a bad check valve, or as a result of the unapproved improper installation. The backflow assembly should be disassembled and reassembled properly before an accurate backflow test can be made.
As a certified backflow assembly tester you must mark this as an improper installation and explain why in the remarks section on your test report. You are required to “inspect” as well as “test” the assembly. Your test report is a legal document, when filled out properly it will protect you from liability.