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Manifolds vs. Remote Valves

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F6Hawk

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Discussion starter · #1 ·
Which is better in your opinion? I can see where the "manifold" concept would cause a higher initial cost due to more pipe (I am planning on using 1" 200 for all laterals, off a 1" SCH 40 mainline), but from a layman's view, I like not having to bury a few hundred feet of wire that later may have to be troubleshot.

Now, I am talking having maybe 2-3 zones in per underground box, and not cramming too many in there. One zone will be within 10 feet of the timer (left side of house, pop-ups), one zone about 20 feetaway (front of house, rotors), and the third zone on the far right side of the house (80+ feet away, pop-ups or rotors), with the lateral being run under the drive to the heads. Of course, there will be future expansion when I install sprinklers in my back yard.

The bottom line is, what are the pros/cons to doing it each way? I imagine you pros have seen it done many ways, and can help me head off future headaches by doing it right the first time.

Thanks!
 
#3 ·
Having all the valves in manifold(s) at one location next to the building may mean more pipe, but in the very long term, not having wire buried in the field will justify the effort. In some cases, the plastic pipe is cheaper than the copper wire, so you can save money with the single manifold. For a do-it-yourselfer, wiring faults can be sheer hell to cope with.
 
Discussion starter · #4 ·
Wet_Boots said:
Having all the valves in manifold(s) at one location next to the building may mean more pipe, but in the very long term, not having wire buried in the field will justify the effort. In some cases, the plastic pipe is cheaper than the copper wire, so you can save money with the single manifold. For a do-it-yourselfer, wiring faults can be sheer hell to cope with.
Click to expand...
Kind of the way I was thinking, Boots, thanks to all for the input. I think having things in one location is nice for those of us who are not pros who like to troubleshoot in the future.
 
#5 ·
At a customers request I recently did a job that had every valve for the system in one location (7 valves).

Manifolding to that extreme was more of a pain than it was worth in my opinion, and I had to stack 3-4 pipe in every trench...Something I HATE doing.
 
Discussion starter · #7 ·
In my front yard, I think I will be able to do a manifold and only have to stack 2 pipes at most. In the back yard, where the presence of 3 or 4 valve boxes is not a large concern, I might just go with running wire instead of pipe. I imagine I will have 3 zones in front, and about 4 in the back.

Thanks again!
F6
 
#9 ·
Having the valves in one location is much easier for service down the road. I also think it's very tacky to have valve boxes in the grass area of the lawn. Whenever posible, we try to put all of the valves together, buried in the landscape rock by the backflow preventer. On most systems, this is usually 5 to 7 valves, it's also one less valve box to dig
 
#10 ·
All different schools of thought.

Cold weather guys want them in one location.

Plus side -Easier to do blow-outs, shorter runs of wire.
Down side - long runs of larger pipe. Means wider and/0r deeper ditches. Several large valve boxes in the landscape area (hopefully there are not more than three valves in a 12X18 box, and never two valves in a 10" round) Real pain to service when there are 5 or 6 valves in one box, the fittings are jam-up and the idiot used crosses to make the manifold so that he could go out of both sides of the box.

Warm weather guys want the valves near the zones.

Plus side - Less larger pipe used if zones are center fed. Mainline pipe and wire in a narrower ditch. Wire path is usually along the mainline so finding piping is easierif using a locator. Smaller valve boxes are less obtrusive in the landscape/turf
Down side - Longer runs of wire, (but 4 strands of 14-1 are less per foot than three runs of 11/4" pipe are. Smaller valve boxes can become hidden under turf - homeowner is still looking for one that has a couple broken wires but doesn't want to pay me to dig the yard.

I will manifold a couple valves if they are at the end of the mainline and it doesn't make any sense to set the valve 100' away and then use the same ditch the bring the lateral back toward the other end. But each valve gets it's own valve box and there is plenty of room between them to work on them if need be.

Just my $.02

Jerry R
 
#11 ·
One further feature the single-manifold (with no master valve) sprinkler system has is no drainage from higher-elevation zones into the lower ones. Not as critical these days with check-valve-equipped heads, but it was sometimes noticeable on older systems.
 
#12 ·
Interesting takes on this one. I don't see how drainage from higher to lower zones when the valves will stop this when they shut off.

We like to use mainline and cable. Much nicer installs. Our frigid climate can give us some late spring and early autumn freezing nites. Valves in the ground will protect them nicely. Great for the homeowner who might forget to shut it off. Might bust a PVC pipe but an easy repair and much less costly.

Having the valves in the yard reduces the chance of breakage and leaking into the house. We pull 25-30% less pipe with mainlines.

John :waving:
 
#13 ·
In theory, you would expect an electric diaphragm valve would be 'off' when unpowered, but I have observed differently. Reverse flow through a diaphragm valve is a given, being that the valve has no ability to prevent it. (test this for yourself, the next time you want to gripe about backflow regulations) It's the forward flow through the unpowered unpressured valve that goes counter to theory. It would seem that some diaphragm valves aren't actually a hundred percent off until they're under some minimum supply pressure. Maybe, after being open, a valve won't be fully seated until the next time it's pressurized. And if you're using I-20's, you won't be seeing the drainage anyway.
 
Discussion starter · #14 ·
If the sprinkler valves work anything like other diaphragm valves I have seen, the POC pressure actually acts as the force which holds the diaphragm closed, until the solenoid moves the plunger, thereby dropping the pressure on the top of the diaphragm, allowing the pressure to push the diaphragm up, and water to flow.

Is this about right?
 
#15 ·
F6Hawk said:
If the sprinkler valves work anything like other diaphragm valves I have seen, the POC pressure actually acts as the force which holds the diaphragm closed, until the solenoid moves the plunger, thereby dropping the pressure on the top of the diaphragm, allowing the pressure to push the diaphragm up, and water to flow.

Is this about right?
Click to expand...
That's it in a nutshell. One other point to remember about this aspect of these valves, as a system is cycling, the next zone actually opens before the previous zone manages to close in most cases. This means that the pressure has to equalize before the first zone shuts off, and the new zone doesn't "pressure up" until the previous zone closes. The Toro "Flo-Pro" was real bad about not closing, especially on intiation, or w/ a master valve. The valves aren't closed because the MV closed first. The MV opens, but all the other zones are open and you get enough blow by that none of them can close. Best solution is to close the flow controls one at a time until the system seats. If it is happening from normal operation and not startup......gut the MV or manually open it so you can't reproduce the problem.
 
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#16 ·
F6Hawk said:
If the sprinkler valves work anything like other diaphragm valves I have seen, the POC pressure actually acts as the force which holds the diaphragm closed, until the solenoid moves the plunger, thereby dropping the pressure on the top of the diaphragm, allowing the pressure to push the diaphragm up, and water to flow.

Is this about right?
Click to expand...
Spot on there.
 
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jerryrwm
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