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Discussion Starter · #1 ·
I am installing my first system and when I turn on and off a zone the whole manifold shakes for a few seconds. I am guessing it's air, and am afraid I should have put in a 1/2" system, instead of the 3/4 I did.

Luckily, this is my own house, and I do not offer this service yet.

Any help is appreciated...

Thanks

Dave
 

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We do not use anything smaller than 1" except for repairs and even then i try to bump the size up.That being said you should do a search on this site on vibration (could be alot of different things) My guess is that you have your 3/4 overloaded (Going past the 5 fps) You have to use hydraulics
 

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My bet is water hammer caused by too much velocity and a valve that closes to quickly. Couple of things you can try to fix it without redoing everything. One is a water hammer arrestor, the other is a preassure relief valve. If you don't put something on the system to release the pressure spike caused by the water hammer, it'll find the weakest point in the system and release it for you.
 

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Discussion Starter · #7 ·
Sorry, should have mentioned I have no heads attached as I am doing this little by little when I get home at night. I have the valves put in, and then I ran a few pieces of 10' poly pipe just to open each valve to make sure they are working.

Would not having the heads installed cause that?

I'd hate to run all my lines and then have to change everything. I am using Orbit valves and they seem to shut off slowly.

Thanks again guys
Dave
 

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Discussion Starter · #9 ·
You do a 1" system no matter what size the line coming into the house is?

We do not use anything smaller than 1" except for repairs and even then i try to bump the size up.That being said you should do a search on this site on vibration (could be alot of different things) My guess is that you have your 3/4 overloaded (Going past the 5 fps) You have to use hydraulics
 

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Is the noise and vibration coming from the valve? Mine do that a little -- more before it was backfilled. There's a lot going on inside that little piece of plastic -- it's hard for it not to make a little noise.

Did you visit here before you started? Orbit is not very well respected. :cry:
 

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Not having any heads makes all the difference in the world. Just opening a valve on a pipe will flow as much water as it possibly can. The heads will reduce your flow into the safe range in a properly designed system.

What size is your meter and your service line? The service line is K Copper? If all you've done so far is run the main and install the manifold with Orbit valves, I'd stop and start over by first designing the entire system and then come back and size your mainline and valves based on your required flow. Just re-running the main and replacing some valves is going to be a lot cheaper and easier than trying to make it work later.

If nothing else, use the Rainbird design assistance. At least then you'll have something that's had the hydraulics calculated to work from.
 

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Sorry, should have mentioned I have no heads attached as I am doing this little by little when I get home at night. I have the valves put in, and then I ran a few pieces of 10' poly pipe just to open each valve to make sure they are working.

Would not having the heads installed cause that?

I'd hate to run all my lines and then have to change everything. I am using Orbit valves and they seem to shut off slowly.

Thanks again guys
Dave
Finish a zone, then worry. A wide-open valve discharge can lead to the hard shuddering you are now experiencing.
 

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Discussion Starter · #14 ·
Yes, noise coming from valve. Unfortunately, I did not visit here before hand. I used to read up on here daily.Just been too busy working and have a newborn at home. It's too late now, I'll replace them as needed I suppose. I am glad you mentioned that to me for the future though.
 

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Discussion Starter · #15 ·
I got a design from both RainBird and Toro and Sprinkler Daddy (Canada) before starting this project. Also read several books, however as we all know there is nothing like on the job training and asking questions. Which is where I am at now. I'll finish up the job tomorrow and hope for the best. Both Rainbird and Toro designed w/ 3/4, so I should be OK. It sounds like I just jumped the gun.

I am using turnseals now as poly couplings, anyone ever use them? Can't find a distributor in NJ. Anyone use anything other than just poly barb fittings and clamps?

Thanks again
 

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Try to use 1" it will make the system work better and you will not have to stock as many parts on your service trucks.

If you heads are not on yet there is your problem... you are breaking all the hydraulic rules.

Before you get to far do the math you may have to split a few zones due to the 3/4 pipe
 

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HydroCutter,

There are guys here that can go into great detail about the hydraulics, but just to kind of get your mind around it, think about all the 1 inch pipe in your system as a giant pressure regulator. Even with a 1/2 inch inlet, once you fill the pipe you have significantly less friction loss than if the whole thing is 1/2 inch.

A line can be too small, but it is hard for it to be too big. Before the flames start, I said it was "hard", not impossible.
 
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