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rabel

Active Member

1

Monday, August 18th 2008, 11:32pm

Too Many Drip Valves?

I am planning a large vegetable garden with many vegetables, perhaps some mushrooms, plus a few fruit trees, some flowering plants along the outside here and there, grapes, herbs, that sort of thing. My admittedly over-engineered design includes 12, yes TWELVE valves, each running a separate 25psi drip line. It's twelve because I've designed in 3 valves for each of four compass points around the garden. Each compass point will have 2 or 3 raised beds, some of which are quite long, up to 30 feet or so.

Now, I'm not planning on planting all that right away, but I can foresee having different watering needs in each area, at least each of the 4 compass points could potentially have their own watering schedule. The planting areas outside the garden and the odd potted plant here and there could add to different watering needs.

So, I figured one valve for each compass point to service the raised beds, then decided to add a 2nd valve at each compass point to service decorative flowers with misters, perhaps potted plants, the fruit trees, etc. Since I'm building all this myself I figured I'd just throw in an extra valve in each of the 4 valve boxes for future expansion.

I'm fine with the costs of the valves and connectors and stuff, but I'm wondering if this is completely over-kill or is it "nice to have" all these extra valves? Someone talk me out of 12 valves for a garden, or not...

Thanks!

Lowvolumejeff

Advanced Member

Posts: 88

Location: Seattle Area

2

Tuesday, August 19th 2008, 12:51am

I CAN DIG IT

Well, I'm a gadget freak, and could easily see doing it your way. However, one of the beauties of drip, is its versitiliy and adaptibility. I plan zones by the watering needs of plants, the type of emitters being used, and by the total volume required.

Once you have established your flow rate, then plan a system using no more than 80 % of the maximum capacity per zone. Since drip is really, low volume irrigation, I find i can water relatively large quanities of plants at one time. Most hose bibs in my area (city water)give at least 5 gal/min, or 300 gal/ hour. That means I can safely use #240 1 gal/hour emitters, or 250feet of 0.9 gal/hour spaced @ 12 inch inline emitter line (netafim) - best fed from the middle of the 250 ft or looped. Thats a lot of beds. Your flow may be greater, or less - effecting your design.

I use single emitters (1 gal/hour, drip along 1/4 inch tubing 1/2 gal/hour on either 6 inch or 12 inch spacing. I don't use misters or sprays, as I don't really want the diseases associated with wet foliage, but that is here in the Pacific Northwest, so your area may be different. I do use spray stakes (shrubblers) that have releatively coarse 8 finger srays, well suited for containers. Shrubblers put out much more water than drip emitters, so require a seperate zone. misters would require their own zone, so you could program them for short duration, multiple run times (as in propagation of cuttings). Probably all your misters in the plan could be run off one valve.

Next, put your plants into groups by watering needs. Most veggies benifit by daily watering (depending of location, evapotranspiration rate, and soil texture). Tomatoes in Texas sandy soil, need 2 or 3 watering/24 hrs. to prevent fruit cracking, wheras in Seattle clay once every other day might suffice (I've grown them in both places).

So, once you have figured out the zones by capacity, frequency, and plant needs - you can proceed with your design.

Remember that all 1/2 inch PE tube is not the same inside diameter. Bigger is better. If you have capacity to set you maximum flow above 5 GPM, you might consider larger (3/4 inch PE tube as it can carry more water - almost twice a much-assuming you have the capacity from your water source.

When buying valves, this sites sponsor, www.sprinklerwarehouse.com sells Rainbird and DIG valves designed for low pressure/flow systems. Rainbird makes a valve, pressure reducer (30 PSI) and filter (200 mesh- for those misters) which is compact enough to fit within a standard valvebox. Personally, I use the Weathermatic silver bullet valve with the combined Rainbird PR/filter combo.

Filtration is the key in drip.

30 PSI is better if using large zones.

You can put individual flow shut off valves (mechanical) on each raised bed, which allows you to turn it off and still water other beds in your quater circle. Usefull when leavin a bed fallow, or between seasons.

All drip is easy to adapt to expansion. Just build the capacity into the flow available per zone.



FYI, I have a seperate zone for container plants. It serves plants in front and back of my house, and even serves to water the hanging baskets. I have my container grown tomatoes on a different zone than my inground ones. I fertigate, so veggies and garden flower and shrubs are on seperate zones. Have 14 zones for my acre yard. 3 are turf, rest are drip.

Hope that helps. If more info is needed, write back. Jeff

HooKooDooKu

Supreme Member

3

Tuesday, August 19th 2008, 10:14am

Three valves per compass point does seem a bit overkill. Mainly because "compass point" seems to be a poor excuse to group plants.

I would suggest that you instead think through two primary issues:

Grouping: Rather than grouping by location, how about grouping by watering needs. As an obvious example, plants that are directly in the ground usually need fewer waterings than plants in a raised flower bed need fewer waterings than plants in individual container. Then different types of plants usualy have different watering needs. Trees obviously need watering at different rates than flowers than vegtables, etc. So, for a moment, forget about WHERE everything is, and instead think about basically grouping by watering schedule. (I can tell you from experience, I too like to have the flexability of controlling as much as possible, hence the desire to have multiple zones in each zone. But in the end, you'll be dealing with too many variables and finally get frustrated to the point where you finally just put everything on the same schedule. In other words, you'll have 12 zones, but only 3 different watering schedules, and you'll kick your self each time you have to change a schedule because you'll have to do it four times over... then you'll make mistakes and only some of them will get changed and not others, then you'll go back and review all of it again and begin cussing the day you decided to have so much flexability).

Pipe Runs: How do you plan on running all this pipe? Are you going to place all the valves in one central location and run all the water out to the 12 zones? Do you instead run one main line out to all four compass points and then have local groupings of valves. Are you going to put some of this pipe underground? I know for my situation, I ran Sch40 PVC from my valves to the flower beds, then came up out of the ground with copper (for durability) that then transistioned to drip tubing within the flower bed. I had one central valve box for 4 drip zones, but then wound up putting lots of pipe in the same trench... something I've been warned is a maintenance nightmare waiting to happen, because if any of the pipes ever breaks, you know it's going to be the pipe on the bottom.

So I would basically suggest that you try to find ways to KISS this project (keep it simple stupid). KISS it from the stand point of minimizing the number of control zones, KISS it to minimize the amount of pipe you have to lay down, try to KISS it from the stand point of getting what you want now but allowing room for future expansion.

So one example of what you might want to think about doing is to run mainline pipe out to the four compass points, run lots of extra wire to each of the four compass points, and build valve manifolds at each of the four compass points, but allow for easy expansion of the manifold in the future. But you have to balance that notion with having duplicate watering schedules in each zone and making it a pain to ever change watering schedules.

rabel

Active Member

4

Tuesday, August 19th 2008, 1:48pm

Thanks guys, you have it figured out spot-on. In my case I am a gadget freak so I want the equipment to do most of the work for me while I stand around looking smug.

Compass points aren't really the criteria, it was just a convenient way to describe my setup, but the point is well taken as to that being a poor design constriant. And I can completely relate to having to change 4 different programs and screwing it up, that's some great advice right there. I'd be ripping valves out of the ground after the third or fourth time I screw up the programming, ha ha.

So, probably my biggest problem is I'm not certain what I will be growing. I have a huge list of veggies and herbs and fruits and stuff I want to grow so I'm hoping to have enough valves and flexibility to add and remove plants however I want. That's really the main reason for the huge number of zones.

Anyhow, I have 80psi and about 10gpm on my water supply (from a neighborhood well serviced by a water company).

So, I think I'll just put one valve at each compass point (there's going to be a semi-raised koi pond in the middle of the garden and the valve boxes are at each compass point around the pond to service the raised beds that surround the pond), but use a 3-way manifold so I can easily add additional valves later if I want.

As for pipes, I'm using 3/4" pvc all around and am planning on just having the PVC come up out of the ground and screwed down to a raised bed, then just have 1/2" poly come out from there. All valves will have 25psi regulators.

A couple of quick questions tho:

1) I'm planning to install a Y filter right out of the source, probably 150 micron. The y filters mostly come with "male pipe thread" MPT attachments and I'm wondering how the heck I connect that to the 3/4" PVC. I mean, obviously I can just use a female threaded connector, but once that's glued down, that filter isn't going to be coming off because I won't be able to unscrew it once it's in the ground. How can I connect the Y filter to the PVC? Is the MPT connection the same as a hose connection? A female buttress connection won't work, is there such a thing as a screw-on FPT connector? The idea is to be able to remove the filter if necessary, although at the moment I can't think of any reason why I'd need to remove the filter altogether. Hmmmm...

2) If I have a 150 micron filter feeding the entire setup, I shouldn't need individual filters at each valve, correct?

3) Does it matter which way the Y filter is oriented? I'm planning on connecting it inside a valve box underground and the filter part would be pointing UP to make it easy to access the filter and flush plug. Does it matter how a Y filter is oriented?

Thanks for all the great advice! I'm sure enjoying designing this system, perhaps I'll post photos once it's a little further along.

Lowvolumejeff

Advanced Member

Posts: 88

Location: Seattle Area

5

Tuesday, August 19th 2008, 3:06pm

Anyhow, I have 80psi and about 10gpm on my water supply (from a neighborhood well serviced by a water company). Great

So, I think I'll just put one valve at each compass point (there's going to be a semi-raised koi pond in the middle of the garden and the valve boxes are at each compass point around the pond to service the raised beds that surround the pond), but use a 3-way manifold so I can easily add additional valves later if I want. Not sure if I follow, what do you mean by a 3 - way manifold?

As for pipes, I'm using 3/4" pvc all around and am planning on just having the PVC come up out of the ground and screwed down to a raised bed, then just have 1/2" poly come out from there. All valves will have 25psi regulators.

With a larger system, I'd try to go 30 PSI, especially if you are going to use spray and/or misters Figure about 8 GPM with 3/4 inch schedule 40, and you do want to use schedule 40 where you will be digging, wheelbarrowing loads of possibly heavy materials. etc. You might want to run 1 inch mains.

A couple of quick questions tho:

1) I'm planning to install a Y filter right out of the source, probably 150 micron. The y filters mostly come with "male pipe thread" MPT attachments and I'm wondering how the heck I connect that to the 3/4" PVC. I mean, obviously I can just use a female threaded connector, but once that's glued down, that filter isn't going to be coming off because I won't be able to unscrew it once it's in the ground. How can I connect the Y filter to the PVC? Is the MPT connection the same as a hose connection? A female buttress connection won't work, is there such a thing as a screw-on FPT connector? The idea is to be able to remove the filter if necessary, although at the moment I can't think of any reason why I'd need to remove the filter altogether. Hmmmm... If you are in freeing area, you may want to drain your system. I suggest 200 mesh if you are using sprays or misters. Wye filters come in different formats, and most show you the direction of water flow as an arrow. Most are screen filters, and mounted with the two ends of the "Y" pointing toward the direction of flow. Do get one with a cap at teh end of the filter leg of the wye, as it makes flushing our easy, and ensures complete drainage in winter. Amazing how much sand is in our water. I use filters spected to 125 PSI, and if designed carefully, youonly need one per your whole system. Make sure you read the specs, and get one that can handle your intended flow. There are a host of commercial filters that can easily service your system, and allow for8 GPM useage. Whichever filter I use, I get 1 inch, MPT and attach it directly BEFORE the valve or manifold (unless I m using extemely high flow rates for a rotar zone on the same manifold). One filter can service most of my systems.I never remove the filters, althoough I will change out the screens if they show wear from the sand or whatever.

2) If I have a 150 micron filter feeding the entire setup, I shouldn't need individual filters at each valve, correct? See above. EMPHASIST 200 MESH

3) Does it matter which way the Y filter is oriented? I'm planning on connecting it inside a valve box underground and the filter part would be pointing UP to make it easy to access the filter and flush plug. Does it matter how a Y filter is oriented? No, but your comment about ease of service needs to be considered. It can also hang down and make draining your system easy.You decide based on the circumstance.

Great project and planning. Let us know if you need more help. One other caveat, I suggest you go with a good pressure regulator. The typical consumer pressure reducers do a good job a lower flow rates (up to 200 GPH) but restrict flow after that. I use Rainbird MEDIUM FLOW regulators (2-22GPM) 30PSI-This will allow you to use more of your 10 GPM that is available. I use the 1" or 3/4 inch ones.(cost about $7) Regulators are ALWAYS inserted after the filter, not before as is suggested in an otherwise excellent online drip tutorial (unlesss we are talking brass, whole system types.)The medium flow regulators need at least 120 GPH discharge, and I find they work best at 300 + GPH. I do not expose them to constant pressure, but place themafter the valve and filter.

Jeff

HooKooDooKu

Supreme Member

6

Wednesday, August 20th 2008, 8:10am


...The y filters mostly come with "male pipe thread" MPT attachments and I'm wondering how the heck I connect that to the 3/4" PVC. I mean, obviously I can just use a female threaded connector, but once that's glued down, that filter isn't going to be coming off...

...Does it matter which way the Y filter is oriented?..

Yea, this is one of those weird catch-22 situations you seem to run accross in plumbing an irrigation setup. After all, from what I recall reading, you're not supposed to ever use PVC-FPT on mainline pipe (pipe under constant pressure). So why do they ever make anything with MPT ment to be installed on mainlines when you're not supposed to have PVC-FPT (it would mean you'd have several copper to PVC transitions to ensure you didn't have any plastic FPT).

You can try to use unions to make it removable, but I can tell you from experience that the fit at the union has to be PERFECT on PVC mainlines. I initially tried to setup my filter and backflow with some unions to I could remove that part of the setup. Well while I was still installing the system, I found I had done something wrong and tried to make use of the unions by replacing just the pipe between the unions. But the replacement pipe was not EXACTLY the same lenght and angle as the original pipe, and those unions leaked no matter how thight they were. I eventually had to remove the whole section and start over.

As for the filter, I don't think it really matters, but I would suggest that you have it oriented either down or side-ways. If you have it oriented up, when it comes time to remove and clean the filter, it would seem that if the filter is up-side-down, you risk having the "stuff" that has been filtered out falling back into the pipes while removing filter. If the filter is down or side ways, it seems less likely that the "stuff" would fall back into the water supply.

I don't see any mentions of a back-flow preventer yet. What are your plans there? DC, RPZ, or PVB.

rabel

Active Member

7

Wednesday, August 20th 2008, 9:05am

Wow, you guys are great, thank you very much for taking the time to respond to my little garden questions.

The garden is situated out in a 1/2 acre "side yard" to my house so for now I've just run the 3/4" PVC up to the back yard and it comes up out of the ground with a hose-end connector. I'm just going to install a typical little hose-end anti-siphon valve coming off the bib and then run a short piece of hose to the PVC. Since I'm not going to use any fertilizer injectors and I'm not tapped directly into the mainline I figured that should be all I need.

I'm sure glad you mentioned the issues with installing the Wye filter, HooKooDooKu. I have been thinking hard about how I was going to install that thing and thought for sure I was just missing some secret irrigation trick to install it. Turns out it really is a PITA and I'm not so stupid after all. :thumbup:

Since I'm coming off the hose bib, I guess I'll just install the Wye filter there. That will make it easy to maintain, although I'll probably have to build a stand pipe. I was hoping to put it in a valve box so I don't have to look at it, but not only would I have to dig a really big hole to give myself room to reach in and unscrew the darn thing, I'd also be faced with the "perfect PVC" issue you described. It's also much simpler that way so I'm applying the KISS principle as suggested.

LowVolumeJeff, thank you too for your great insight. I'm really getting sort of excited about the possibilities with the drip system.

I'm going to use a 3-valve valve manifold in each valve box, but I'm only going to install one valve and cap the other two valve outlets. I'll still run all the pipe and stuff, but it's becoming clear I don't really need 12 zones any time soon and with the flexibility of different drippers run off the same 1/2" poly line, I think I'll have all the variety I'll need for various areas of the garden.

Ok, I'll run 30psi off the valves, thanks for that advice! I've already run all the 3/4" line into the valve boxes, but I might run 1" from the valves to the raised beds since those are probably the lines subject to the most abuse. If that's a waste of time I'd like to know, since working with 1" pvc is such a hassle (compared to 3/4). I am using SCH40 PVC... I think. It's just normal everyday PVC pipe from Lowes, I assume it's schedule 40. Anyhow, most of it's already in the ground, so I suppose I'll just fix it if it breaks.

UGH - I went to the trouble of designing the valves to go from 3/4" inlet to 1" manifold with 1" valves. But I can't find a 1" pressure regulator, darn it. There is one 1" PR on the host site, but it's $15 and doesn't even go as low as 30psi. So, looks like I'm going to have to redesign the valve manifolds to support 3/4" all the way around. Does anyone recommend 1" lines from valve/pressure regulator to the raised beds or is 3/4" all around good enough? Or would I just come out of the 1" valves and drop back down to 3/4" for the PR?

I'll use a 200 mesh filter instead of 150. There is one zone of impact head sprinklers serviced by this same line, so I'll find a filter that can handle the 9 to 10 GPM flow I have. Hmm, the P16-155 Wye filter at sprinklerwarehouse doesn't mention a GPM limit. Will that filter be adequate to service 4 (maybe 12 some day) drip zones and 1 zone of sprinkler heads?

I'm in Central Texas (Austin area) so freezing isn't really much of a concern. We get maybe 6 days of freezing temps a year, 6 days in a row in a really bad year.

However, this reminds me of yet another question. The ends of all my lines have flush valves, and I was planning on just opening up all the flush valves and finding some way to hook up my air compressor to the system to just blow out all the water in the event of a hard freeze. Is that a bad idea? I've got a nice DeWalt air compressor with an adjustable psi, so I can limit it to 20psi or whatever, rather than trying to blow 200psi into it and destroying everything. How does one normally flush out the system? I'm not nearly sophisticated enough to have the entire 100' x 60' irrigation area on some sort of grade so that there's a single low point to use for a drain valve...

Thank you both very, very, much. I do appreciate the advice and I'll stick around to contribute on the forums as I become more experienced.

This post has been edited 3 times, last edit by "rabel" (Aug 20th 2008, 11:56am)


rabel

Active Member

8

Wednesday, August 20th 2008, 11:31am

Let me add that I have been reading around the forums and wanted to save someone else the time discussing hose bib issues. I read HooKoo's lengthly explanation in another thread about hose bib connections.

My hose bib is actually directly connected to the main. I know this because I installed a water softener for the house so I tapped into the mainline coming into the house to route the water supply all the way around the house to the garage where the water softener is installed, and back again (with a fancy all-brass cutoff valve system I built, it's cool, if I do say so myself).

Meanwhile, on the way to the garage I also cut the garage hose bib supply (that was coming from the house) and tapped it into the supply coming directly from the main so that it would not have softened water coming out of that bib.

So, while there is certainly pressure loss and noise and what-not coming into the bib that will be supplying this drip system, it's just about as good as it's going to get. At 9 to 10GPM and 80psi, I think it's pretty good.

Thanks!

Lowvolumejeff

Advanced Member

Posts: 88

Location: Seattle Area

9

Wednesday, August 20th 2008, 12:27pm

Howdy Texan

Lived and attempted to Garden in DFW area for 30 years. I had to rely on overhead and soakerhoses on all my beds due to the hard water. Hardness is a function of the amount of Calcium Carbonate in your water. The Austin Chalk comes to mind. That disolved cacium will clog many drip emitters, including many of the "drip-along" types we find so popular. Many who use drip in areas of hard water, and rationing use "Flag" type emitters, because you can easily clean them. They are not pressure compensating, but easy to use on a 1/2inch PE tube. Know a gardener in Arizona that cleans his every 3 months or so.

So, what type of drip is being used in your area? You might want to research and determine how long it is used before clogging or leaking becomes a problem.

Don't overthink the filter. Even 200 mesh doesnt remove th Calcium. I used to use reverse osmosis with charcoal to clean out the calcium and chlorine, and we would use that water in the grenhouse so as not to leave tell tale white deposits on the orchid leaves.

I teach drip irrigation courses top homeowners. Their most comon application is by hose. They can buy electronic valves that fit on 4 way brass maniofolds, battery powered, and can b expanded. look in C*stco in the spring, they feaur a 4 way brasss hemanifold, 3 electronic battery valves, quick connects (brass) for $42. Made by Orbit, you can ge a 2 valve packace at H*me D*pot (about $50 and buy addition battery valve for $17). I suggest to my students, they construct the head assembly in this order. Spigot - Timer -backflow preventer-filter, pressure reducer, hose to emitters. Useing a manifold can complicate this depending on how the outflows are goin to be used (you don't want to reduce the pressure in a line going to an impact sprinkler for example). The important thing to remember is that those plastic parts sold with hose end connectors (MHT & FHT) are not designed for use under constant pressure. So place them after the valve or timer if used.

Winterization is EASY. Do not blow out micro drip lines with air, they are designed to drip out water, Poly Ethylene (PE)supply lines expand more than the expansion of water when frozen (water = 112%). I put an emitte rat the low spots on a system. Open the ends and most importantly, take all those hard plastic "Head" pieces off the hose bib, drain them, and take them inside for the freeze. They will break.

So again, the timer, backflow preventer, filter, and pressure reducer need to be kept above freezing, or you will be replacing them.

MPT & MHT confuse many. Filters come in both styles, and are made so they can bbe screwed into an inground valve and pressure reducer, or used on you spigot. The direction the opening points is of no conequence of how a wye filter works, just position it so it doest hit you in the face when you flush it.

Do some research about who else is sucessfully using drip in the Austin area, and you may find a soakerhose your easiest solution. I have used them on a multiple raised bed garden in Texas, and can give you some pointers if that is the direction you decide to follow. Even soakers become clogged, althouogh I found they worked well for 5 plus years in my garden.

Jeff

Lowvolumejeff

Advanced Member

Posts: 88

Location: Seattle Area

10

Wednesday, August 20th 2008, 12:37pm

Our post crossed in the mail

Looks like yiou and I were writing our last post at the same time.

You do have hard water, and yes, it is imparitive you don't use water that pases thru your "softener" as it exchanges sodium for calcium, and salt kills most plant (You knew that, but as other thing I write, meant for all forum readers).

Hose bibbs for HIGH VOLUME irrigation are a noise and pressure problem. For most drip (low flow/volume & low pressure) it is not nearly so problematic. I have run 300 GPH systems off hose bibbs without noise or other problems, but it depends on you circumstances.

9 to 10 GPM is way more than you need for drip. More is not a bad thing, and certainly builds flexibility into your system. You can make a good system with 5GPM - (300 GPH) or less, just may have to have more zones.

Check with locals about the hardness issue.

Jeff

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