Irrigation - Some valves have no head elevations in the valve schedule

Steve,

Here's a picture of me wondering what could cause this.

For anything more substantive, we'd need the file.

--J

This is just the irrigation file. To size the laterals you will need the planting base too.

Here is the planting base if you need it.

BTW, Lookin good Bro.

Steve,

I noticed valve C2 served Bubblers, and had no head elevation.
I went to size its laterals, checked the box for spot elevations, and it promptly displayed 0.5 feet of elevation difference. After sizing, the Analysis correctly shows 0.22psi of loss, and the valve schedule now shows 0.5 ft of elevation difference.
When I try to size all valves, I do get an unsizeable valve message, so perhaps that is what happened?
If you size each valve one at a time, it should work perfectly for you.

--J

We sized each one individually. (What a bear that was. But not as bad as sizing each one individually the old way without LandFX). But there are still four (4) valves that will not size recognizing the elevation differential between the valve and head. I opened a ticket and sent a zip file with the drawing and the planting xref since some of the valves are connected to individual emitters based on the planting. I look forward your response which I will post here for my future reference and the reference of others. Thanks.

Steve,

When troubleshooting spot elevation issues, the simplest method is to draw a circle from the point in question, to the first spot elevation arrow that is encountered. In this instance, you can see that if we draw a circle from the pipe endpoint in the drip area, the first spot elevation encountered is the one closest to the valve. Hence, no elevation difference.
But even with the naked eye, it is quite challenging to determine which spot elevation is intended to be used for that drip area -- there are 3 spot elevations around its periphery, all with different elevations. A single spot elevation pointing to the middle of the area would not only be obvious to any plan-checker, but also to Land F/X.

--J

Hi Jer,

We put spot elevations at the end of every lateral line serving a drip area. I'm not sure why the program would look for the closest spot when calculating loss. Logically, it should be looking at the spot elevation closest to the furthest lateral line termination point (or last emitter really. But I know that we're not there yet.

In the case of B5 the furthest lateral line termination is at the flush valve. There is a spot elevation there. Shouldn't the program be looking for a spot at the valve (shown as 4454.8) and a spot closest to the termination point (shown as 4455.7)? That would be a differential of .9.

Further, if the differential is 0, then the valve schedule needs to show that instead of looking like it just wasn't calculated (which looks the same as a blank).

I'm sure that I'm missing something, so please enlighten me. There were four missing. Please confirm that your response is valid for the other three that are not showing up. If you or Jake want to call me, please do. You both have my number.

Thanks in advance.

Steve,

While the run to the flush valve is certainly longer, it is discarded as it is just dead-ending in a flush valve, and does not affect the sizing. The other dead-end is used for the sizing calcs, including the location of the nearest spot elevation.
As for the other valves, I looked at B9, which has the same issue - there is a spot elevation next to the flush valve at the very end, but nothing at all of the individual beds -- 24 of them! From many of the beds in the middle, the closest spot elevation is the one next to the valve, which is the highest elevation, which is what is used. So again, the best solution here is to be sure to place a spot elevation smack in the middle of each drip area, that way it is extremely obvious to even the naked eye which one is closest.

I agree that the valve schedule should have some indication that no different elevation was found, to differ from the case where no spot elevations at all were found. I have added this to our wishlist.

--J

Jer and Jake,

If we are irrigating a parkway and the street is a constant grade and the flows to the individual drip areas are similar, then I would suggest the following:

Spot elevation at the valve is obvious. But the next points to look for would be the furthest from the valve in every direction. Definitely not the closest to the valve which may be the furthest for another valve (a bubbler valve or rotator, or drip (you get the jist.)), but irrelevant for the purposes of the valve in question. Once the furthest points are determined, the program will check all ends to see which is the worst case. Is it the furthest, or is it the highest?

Why wouldn't the above method (which seems logical to me) work? Why in the world would we want to spend the time to add spot elevations to each and every drip area or emitter area if only the furthest is relevant. Beyond that, why wouldn't the program triangulate to determine the approximate elevation at locations along the way from point A to point Z?


I do understand that the flush valve is just a dead end now. There is no need to calc flow.

If it's easier, just call.

Seaweed (Steve Cook)

I need one of you to call me.

This just isn't making sense. See the attached file. The valve has a spot elevation of 52.0. The furthest has a spot elevation of 49.5. The furthest in the other direction has a spot elevation of 51.5 but is significantly closer than the other. But it is higher in elevation than the other. The program should first run a calc to determine which is the worst case regardless of elevation and then add the elevation differential to determine worst case pressure demand. In our example (attached file), neither are a zero-elevation difference, but that's what the program is stating that the difference is (see second attached).

So, as I explained in my previous message, the important information is the valve elevation and the elevations of the furthest areas being supplied by the valve.

Without adding an elevation to each and every area supplied by the valve (which may be important if the lateral went up and down rather than at a semi constant grade), what must I do to make this work?

Really it may be best to call.

Steve Cook