# Question on best way to turn on main valve



## Green (Dec 24, 2017)

Last year when I activated the irrigation system, here is what I did:
-Slowly opened the main valve over about a minute or so, until the line filled
-Then ran the furthest zone until sputtering stopped. Then the second furthest, and so-on.

I'm wondering if it actually would have been better from a pressure standpoint to run the furthest zone before fully opening the main line. Maybe only go halfway, and let it fill that way. Maybe that way, the sputtering wouldn't be as violent? Our pressure is fairly high; I haven't measured it, but it's on the high side. Don't want to damage any lines or anything.

Which way is better?


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## gijoe4500 (Mar 17, 2017)

I'm assuming you are trying to avoid water hammer? The safest way to avoid it would be to fully open the whole system, them close everything off, starting at the closest to the valve first.


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## Green (Dec 24, 2017)

gijoe4500 said:


> I'm assuming you are trying to avoid water hammer?


Correct.



gijoe4500 said:


> The safest way to avoid it would be to fully open the whole system, them close everything off, starting at the closest to the valve first.


What do you mean "open the whole system, then close everything off"?


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## gijoe4500 (Mar 17, 2017)

@Green turn on all zones. Everything, wide open. Then turn on the main valve. Then turn off the zones one at a time, starting at the one closest to the main valve.


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## Green (Dec 24, 2017)

gijoe4500 said:


> @Green turn on all zones. Everything, wide open. Then turn on the main valve. Then turn off the zones one at a time, starting at the one closest to the main valve.


Interesting. Never heard of that being done. Is that how you do it, and did you hear about this method somewhere originally?


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## gijoe4500 (Mar 17, 2017)

Green said:


> gijoe4500 said:
> 
> 
> > @Green turn on all zones. Everything, wide open. Then turn on the main valve. Then turn off the zones one at a time, starting at the one closest to the main valve.
> ...


That's what we would do with water main piping when I worked for the water company. Except it was flush valves instead of sprinklers.


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## Green (Dec 24, 2017)

Let me run it all by you. Tell me if anything seems out of order the way you do it.

-Open all zones first
-Then slowly turn on main valve. I'm thinking it might take a few minutes with this method. In theory, water should fill the whole system, expect maybe for some air gaps that are unavoidable no matter what you do?
-start closing zones, starting with the closest, and close all except the furthest. Only thing is, I don't remember for sure which valve is the closest zone and which is the furthest. They're all in a line in the box.
-Let it run until the air is out.
-Then test all zones


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## gijoe4500 (Mar 17, 2017)

Pretty much. Except you don't need to open the valve that slowly. 15ish seconds from close to open should be fine. Even if you were to slam it open, its not going to water hammer if your zones are all open. Then let it run for a couple minutes. shouldn't take anything crazy long, maybe 2-3 minutes tops? Then start closing the zones 1 at a time.

Even then, this is all pretty much overkill.


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## GrassDaddy (Mar 21, 2017)

I open it partially and then run each zone, then I slowly open it the rest of the way and run each zone again (using the 1min test button).

Afaik the real problem is the pressure of the air in the lines if you open too fast that can make the head pop out or get damaged. The fast high pressure air can also heat up the gears which is why when you are blowing out the system you don't want to run it too long after the water is out.


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## Green (Dec 24, 2017)

GrassDaddy said:


> I open it partially and then run each zone, then I slowly open it the rest of the way and run each zone again (using the 1min test button).
> 
> Afaik the real problem is the pressure of the air in the lines if you open too fast that can make the head pop out or get damaged. The fast high pressure air can also heat up the gears which is why when you are blowing out the system you don't want to run it too long after the water is out.


Thanks for your input, too. Extrapolating from what @gijoe4500 said, a partially open main valve might actually increase water hammer due to narrowing of the pathway...sort of like artery narrowing in people. I'm guessing that wasn't an issue when you did it that way. Maybe it depends on your supply pressure.

I think I'm going to try the all valves open method.


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