Sprinkler system for large park type area

[DavesTractor]

I bet we have some sprinkler experts here. I've installed a few systems, so I know the basics. But we have decided to do a larger area now and this is a big pump, so I am beyond my area of expertise.

We have a 200 GPM 15 HP pump that is set up with VFD for a constant pressure system. It will actually put out about 225 GPM wide open as my static water level is at 24 feet. The area is an irregular shaped 7 acres, like a park with about 200 trees scattered around. I thought I'd design for 180 gallons at 75psi.

My idea is to use a 4" mainline which should be ok at flow rates under 200 GPM. 3" electric valves, where I will "T" off into a pair of 3" lines, the step down to 2" further down the line. I'd like to use in-ground popup sprinklers that have a minimum radius of 60'. I have PGPs in the lawn areas near the houses, but I want a lot more radius for the field areas.

Any suggestions on sprinkler types? Any favorite valve types for these larger sizes?

 

[boggen]

the main line / reducing and teeing and like. i am not a big fan of.
--it costs a little more, but simply prefer running a pipe to each and every spot, directly back to a central location, were valves can be placed. it allows for so much more control over things.
--its not that hard to run multi pipes in same trench.
--as soon as you put multi anything on same water pipe and only a single valve controlling them, you end up having one getting more water than another one. and all it takes is a little bit of dirt, or something, and it throws the entire system off, of which item gets more water vs the other. you may not notice the little thing, but you will notice all of a sudden one sprinkler only getting half the area it use to or a few feet it use to but no longer. that is were running every a pipe for every single thing back to a central spot, were valves can be placed comes in.

if ya want to install say a 55 gallon drum some place under ground, and then come up off it for a man hole / steel lid. so you have spots here or there, to install your individual electrical valves, and like, might be an option.
--if doing above, it would be like install a french drain. drill a bunch of holes in bottom 1/4' of the drum around it sides and bottom of the drum, then dig down a few extra feet and around the drum, back fill with river rock a couple feet, put a fabric around the drum were the holes are to help keep mud from washing back into the drum. drill holes were needed to bring your piping into the drum, and install your valves and like. then back fill around drum with rock to cover the holes on drum. place another piece of fabric down, and then fill up to ground level with dirt. with some sort of man hole cover.

with above said, valves more so electrical valves are very costly. and they nearly double in price as you go up in size. figure out cost of larger valves, vs just ordering a larger roll of smaller pipe and smaller valves. and see what the difference is.

 

[DavesTractor]

Thanks Boggen. On the last system for about 15,000 sq ft of lawn around the houses I had valves in banks and then ran a ton of pipe and not much wire. Sometimes several runs of 1-1/4" pipe in a trench. But with 4" pipe off my big pump, it is way cheaper to run a mainline or even a looped mainline and place the valves out in the field. 3" valves are about $250, but I'll only need a handful of them for 7 acres. I like the idea of using a buried barrel with a steel lid for a valve box. That way there will be plenty of room to do repairs later if needed and I can drive over the lid with a tractor while mowing. I appreciate the feedback.

 

[boggen]

head over to www.koiphen.com and search various DIY ponds folks have built. you will find a lot more ideas. for buried vaults and like. lots of folks digging in and install valves below ground around there ponds. to central location setups, etc...

though i am still going to push for multi small lines. vs 1 larger main line. i realize there is issue between you knowing the area and layout of things vs me not. but... still going to push for multi small lines, so if something comes up as ya putting stuff in, you will more likely go with multi small lines to each sprinkler. vs running more of the main line. the control freak part of me and making things easier to adjust later down the road has me. *shrugs*.

another issue is getting pipes in deeper into the ground....
can be fairly easy to destroy a "septic field" by running to heavy of a vehicle over a septic field, and crushing the 3" more like 4" pipes, or crushing the chambers that make up a septic field. sprinkler system, i really do not see much different. when the pipes do not get buried very deep. (thinking going to drain for winter approach). and with that get below frost depth for your area. if ya putting this much pipe in...... i am guessing you will be renting a trenching machine. and/or backhoe, or perhaps a "ditch witch". spend extra few minutes on each run on the machine and get the stuff deeper. not going to harm anything beyond initial install time.