Valve diaphragm

[T-Trim]

Hello

Q: Is 10 plus years of valve operation normal without replacement of the diaphragm . I hope not this commercial property I do . Is having watering at odd times, not programed in the timer. Are the valves diaphragm's at fault

[Dirty Water]

Probably not.

Once a diaphragm fails, the valve usually sticks open.

Have you checked to see if you have multiple programs stacked on the timer?

[Greenguy1]

sounds like a sneaky B and/or C program virus

[PurpHaze]

Is 10 plus years of valve operation normal without replacement of the diaphragm.

All depends on a lot of factors but many diaphragms last longer than ten years. Others don't.

Is having watering at odd times, not programed in the timer. Are the valves diaphragm's at fault?

The controller is the brain... valves are the muscles of the system. They come on when the brain tells them to. Like DW says, a hung valve is usually caused by the diaphragm. Check the controller's programs.

[Greenguy1]

The only diaphram's I have changed in 20 years were the old TORO hydraulic type and they were probably 15 years old. I am sure your problem is a timer issue,a bad diaphram will do one of two things, not shut off if there is a hole in it or not turn on if there is a plug in the transition port hole in the center

[Kiril]

I've changed out alot of Irritrol/Richdel diaphragms over the years.

[T-Trim]

Thank you for all of your guy's input. I double checked the controller for stacked start times and I've found none. So far to date I just set the timer to every 3rd day. I can't remember the model even knowing I been called out many times last week to fix the problem. I just set the every 3rd day timing just yesterday. It's a rainbird ESP with 8 zones. Most of the heads are maxi paw and t-40. I've started replacing them with my fav Hunter I-20 and PGJ. It's a slow change over

[WalkGood]

Unplug the controller or disconnect the problem zone's wire for a day or 2. If the zone still comes on, then it's not the controller.

[FIMCO-MEISTER]

Unplug the controller or disconnect the problem zone's wire for a day or 2. If the zone still comes on, then it's not the controller.

Maybe somebody will dispute me but valves do not randomly come on without power. The problem with this type of troubleshooting is you still have to depend on another HUMAN BEING to tell you if it has come on and they often confuse dew with a sprinkler system running.

[WalkGood]

Maybe somebody will dispute me but valves do not randomly come on without power. The problem with this type of troubleshooting is you still have to depend on another HUMAN BEING to tell you if it has come on and they often confuse dew with a sprinkler system running.

True, the heads spraying has to be verified. If a reliable witness is available, the controller error can be eliminated.

Under a rare circumstance, hard water hammer on a "marginable" weak diaphragm *could* cause the valve to come on without power.

[SprinklerGuy]

I have seen it cause a valve to come on momentarily....it will not stay on however as once the hammer subsides the valve shuts....

[T-Trim]

well the system is in a commercial setting. I was thinking it was the water hammering effect too. But I don't sit there all day and watch the system run.
I have no problem sitting and watch, cause I will still get paid.

[PurpHaze]

I have seen a "valve come on momentarrily" in large systems with large lateral lines where the diaphragm is experiencing weep-by. The lateral lines build up enough pressure in them to have some of the sprinklers pop up slightly and spray until the water pressure buildup has escaped.

[Greenguy1]

the only valve problem I have experienced is a problem that just arrived yesterday the system would not switch to the next without a Minute and a half in between, I quickly realized that all the heads were below grade and that gravity was pulling on the valve that was to shut off while the other was trying to turn on creating a low pressure overlap I simply put the zone on last ... problem solved!!!

[Greenguy1]

what would you do PUP I mean purple?

[FIMCO-MEISTER]

the only valve problem I have experienced is a problem that just arrived yesterday the system would not switch to the next without a Minute and a half in between, I quickly realized that all the heads were below grade and that gravity was pulling on the valve that was to shut off while the other was trying to turn on creating a low pressure overlap I simply put the zone on last ... problem solved!!!

That's pretty amazing that you've had one valve problem in your career and you solved it so quickly.

[T-Trim]

If this helps any, The one zone is all maxi paw's after shut off all on the low side of the zone stay up halfway. Is that normal or not? if not is it just a rotor head related problem? Thank you

[PurpHaze]

If this helps any, The one zone is all maxi paw's after shut off all on the low side of the zone stay up halfway. Is that normal or not? if not is it just a rotor head related problem? Thank you

Depending on amount of slope you will have low head drainage which at times can keep downhill sprinkler heads semi-popped for a little bit until sufficient water has drained out of the lateral lines.

[PurpHaze]

the only valve problem I have experienced is a problem that just arrived yesterday the system would not switch to the next without a Minute and a half in between, I quickly realized that all the heads were below grade and that gravity was pulling on the valve that was to shut off while the other was trying to turn on creating a low pressure overlap I simply put the zone on last ... problem solved!!!

Doubtful that gravity has anything to do with it... more like the diaphragm is having problems overcoming the main line side pressure and completely closing for a short period of time. When the second valve opens it takes some of the pressure away from the first valve until the first valve can then close completely.

My solution... throttle down the flow control of the first valve a little, replace the diaphragm or program in a delay between stations on the controller (if it's a good enough controller to have this feature). It's pretty obvious that the main line GPM/PSI is insufficient to allow two valves to be actuated at the same time. This is also a trick when using a remote and you have a valve that is slightly hung up and won't go down immediately... remotely fire a couple additional valves to steal the GPM/PSI from the valve not closing down. It will then go down and you can shut off the other valves.