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RPZ repair...

kcopp Member Posts: 4,395
Watts 009 rpz on an irrigation hook up. Replaced just last years.
Was removed and brought inside supposedly last winter.
Installed this spring. Worked fine for a couple months and then it starts bowing water through the vent.
Pulled the unit apart and the main diaphragm was very distorted.
I tried to re-build w/ the Watts kit but to no avail still blows out water the minute water is tuned on to the rpz.

Any helpful hints?


  • Intplm.
    Intplm. Member Posts: 1,801
    The "sending" tube or port that sends water to the relief valve to help close it is probably fowled with some type of debris not allowing it to close, or the first check has a small defect or cuts in it.
    What size 009 is it?
  • kcopp
    kcopp Member Posts: 4,395
    1".. I pulled it all apart and replaced the parts that were in the kit. it all looked fine.
  • Intplm.
    Intplm. Member Posts: 1,801
    The double "o" series is much harder to work on than the watts 909.
    On this unit, there are commonly three repair issues that are offered in kits.
    They are the first check, second check, and the relief check kit.
    Have you changed all of these?
    It might be damaged from ice forming over the winter, Even if it was blown out.
    If the repairs do not work I would replace it with a watts 909 or a Febco 825.
    Both of these units are very reliable and very service friendly.
  • kcopp
    kcopp Member Posts: 4,395
    I have been told that the Unit was disconnected and brought inside during the winter. There are unions there to make this simple. By code RPZ are not allowed to be exposed to freezing temperatures.
    Now... they may have not been telling me the truth.
    I replaced the diaphragm and the check valves. Also greased them w silicone grease.
    I will probably end up going w/ a PVB instead because RPZ seem to be pretty failure prone.

  • Intplm.
    Intplm. Member Posts: 1,801
    RPZ's are not really any more failure-prone than any other device.
    Some are just made better than others.
    If you go with an RVB, or what is considered a "low-hazard" device, you can have the same problems in the future that you are having now.
    Also, you will be changing the device from what is considered a high hazard to a low-hazard device.

    "(Low hazard)" can be used when "ALL" irrigation equipment is below the device.
    If just one piece of equipment in the irrigation system, ie. a sprinkler head is even with,... or above the device "( the high-hazard device is required)" hence the Watts 00 series.
    If you determined that you need a High hazard device, I would change it to a 909 Watts BFP. It's a better device that is much more service friendly but does cost more. Or look into the Febco line that I mentioned in the above post.
    These are the rules that are code and department of health requirements in my area.
  • kcopp
    kcopp Member Posts: 4,395
    Thanks...I understand the difference between a RZ and a PVB.
    The biggest problem I see w RPZ in irrigation set ups is that some irrigation folks will blow through these w/ air and they end up blowing out the seals. I have seen this time and time again.
    PVB's are Much more robust.
    The town i am in used to require RPZ bfp until last summer. they finally reduced the need for them when the situation of a PVB could still provide protection.
    This house will be fine with a PVB... I was just hoping to save this customer some money by repairing it.
    Im pretty sure that the irrigation company did something to cause this failure.