Wilkins 975xl Flow/Pressure Issues

[dblackburn]

I have a Wilkins 975xl backflow preventer. It is removed every winter and passes its test before every spring. That said - my sprinkle output is very weak. Each time I run the sprinklers I have to shut off the water coming from the Wilkins and open the three relief valves. This can be done in any order - once all three are open - I shut them off one at a time - open the water valve back up - and my sprinklers run just fine.....

Once done all 5 zones run normally. There are no visible leaves from the preventer.

Thoughts?

 

[Gary Swart]

Has it always done this? I have a Wilkins BF also, not sure of the model #, but your description is quite similar to mine, and I have never had this problem. I will be following this thread to see if there you get an answer to your question.

 

[Sponsor]

 

[WorthFlorida]

It seems that there must be air in it and opening all relief valves essentially primes it.

http://backflowparts.com/wilkins-model-975xl-975xl2/
http://backflowparts.com/wp-content/uploads/2016/03/Wilkins-975XL-.34-2-New-Repair-Procedures1.pdf