Nozzles for Orbit 5400 series spray heads

I've got a large plants only area with Orbit 54118 pop-ups with adjustable nozzles (link).

These spray heads come with 12' and sometimes 15' nozzles. I measured from head to head to find out what type of nozzles I need, however it's all over the place.


Note:

1. there's a very slight downward slope from the bottom (of the image) to the top.
2. the maroon line is an area that will not have any influence on the selection of the appropriate nozzle for the surrounding heads.
3. the 11' dotted line is a direct measurement (not to another head) of the area the nozzle should be able to reach.

The two full circle spray heads in this image were replaced by Hunter pro 10' adjustable nozzles (no fixed spray available in this radius) but it does not sit flush with the wiper seal. Oddly enough the pre-installed Orbit nozzles are made by Hunter for Orbit and these replacements still aren't a perfect fit. When using Rain Bird nozzles on these Orbits, there isn't this issue.

What is the best radius spray nozzle for each head?

 

Generally I like to have the spray from one head reach the next so you have double coverage between them.

 

Head to head coverage is no issue, as I have mostly 12' and few 15' nozzles right now. There is a lot of water spraying in areas that don't need it, so I am trying to find out which nozzle would work best given the measurements.

 

The odd spacing between your spray heads makes setting up a bit more difficult. It is sometimes impossible to not have over spray in some areas. It seems you can never have enough different nozzles when setting up a system. The half, quarter and three quarter radius nozzles are helpful but I don't like the performance of the ones that are supposed to spray a square or rectangle off to the side of the head.

 

What about you GPM?

Are those 11 heads on one zone?

 

That's 11 heads on one zone. Not sure about GPM, though the pressure seems strong. Going to use a hose bib water pressure gauge to get a psi reading this weekend.

Basically, once I get the psi, I can look on this chart for say, the 5' full radius MPR nozzle and if the area I need is 5' and I've got a psi of 30 or above, I should be good?

 

I think 11 heads on one zone is too much unless you have a big supply line all the way from the city main. What size water main and meter do you have? What size line running to your irrigation system? I would start thinking of breaking it up into two or three zones depending on the supply you have.

The pressure at the spigot will give you a static pressure reading with no water flowing but that is of little use. You need to know the minimum pressure your system can maintain when flowing the GPM that your sprinklers will take. You can open a spigot all the way and see what that does to your pressure but it will be difficult to simulate the massive flow of 11 heads and what that will do to the pressure. With my irrigation system I opened spigots until my system could only maintain 30 psi then I measured the gallons per minute and used that number to tell me how many emitters I could have on each zone.

The 5' radius heads seems way too short a range and will give you many gaps in coverage. I think you should be using mostly 12 and 15' heads which unfortunately flow considerably more water.

You also mention using Orbit brand but linked to Rainbird emitters. They are very similar but may be different. If considering Rainbird I strongly recommend taking advantage of their free system design service. They tell you how to test your system for flow and pressure. You submit a sketch of the area you want to irrigate and they send you back a plan how to best make it work including where to put emitters and what type to use.

 

So this area is not grass, I wouldn't worry too much about it if the pressure seems ok , however if the pressure is low you can change out the sprays with stream rotors they have the same threads as either male (Toro style) or female (everyone else) aka MP ROTATORS which have huge coverage at very low gallonage some @ 22 ft 1/2 circle only use between .5-.7 gpm at 30 psi. an easy solution to low pressure problems, adding zones would be major work for average homeowners. As I see it you can easily water that area for less than 11 gpm with conventional sprays