Lawn Sprinkler System - Page 1
Forum section: electronics / general

author: bostonman
author_rank: Super Contributor
timestamp: July 18, 2019, 05:59:58 pm
content: Crazy question, but does anyone know if the lawn sprinkler heads can be connected directly to the water supply without the need for valves?Other than timing and zone control, I don't know what the valves are used for. I'm thinking of just connecting underground PVC pipe directly to my outside faucet and installing sprinkler heads in various locations. Someone told me without the valves, pressure will not be enough to get the sprinkler heads to pop up from the ground.Obviously if I take this route, I'd need to manually open and close the outside faucet, but it would save me lots of time/money by not installing valves.

author: bob91343
author_rank: Super Contributor
timestamp: July 18, 2019, 06:17:24 pm
content: I don't know about your setup but here the water pressure is supposed to be around 45 pounds per square inch. Check your area and look at the valve specifications. If they are compatible, you are good to go.

author: Dundarave
author_rank: Regular Contributor
timestamp: July 18, 2019, 06:18:36 pm
content: You need valves to control the zones, and you need zones because your water pressure can only “power” a small number of heads. If you need a dozen heads for full coverage, you can’t have them all running at the same time.My system could only support something like 3 heads at 70 psi, so I needed to set up multiple zones to cover the lawn, garden, etc. The control box would then cycle through the zones, a different part of the yard for the preset time.YMMV, of course, but if you’ve got just average household water pressure and need to use more than a few heads, you’re going to need to use valves to make it work, either manual ones or the standard 24 volt ones.

author: bostonman
author_rank: Super Contributor
timestamp: July 18, 2019, 06:32:23 pm
content: That makes sense because I didn't think the valves open and close like a pressure washer to increase pressure.I know overlap should exist with sprinkler heads, but I don't have a huge front lawn. At a coverage area of 15' radius per head, I'm thinking maybe five heads would be enough to cover my lawn. Currently I have two of the ones that move left to right. They are stuck in the ground with a garden hose connecting them and a garden hose from my outside faucet to the first one.From what I can tell, I get good pressure with those two, however, more ideal would be heads centralized spraying water in a radius rather than left to right where many areas are not covered.If only three heads can be "powered", having five or six on one line probably won't work then. I know the valves also use electricity, so not only the higher water bill, but it costs electricity to run. Ignoring the cost of a professional to install a system, I'm not a fan of having a water system rely on a series of items that can break and cause my irrigation system to run by accident. So it's another reason I'd like to have a manual system.

author: Dundarave
author_rank: Regular Contributor
timestamp: July 18, 2019, 06:46:34 pm
content: You might want to consider doing a bit of R&D: buy a hose bib pressure gauge at Home Depot (and take it back after, lol) to measure your water pressure. You can check out sprinkler heads there too... Each head has its own coverage and pressure specification, you can find them on line at the manufacturer site.Then take some graph paper and sketch out the area, plot the heads, and from there you’ll know what you need.I had great success with my lawn and garden on automatic. It consumes essentially nothing in electricity: I’m sure the various wall warts I have around here out-swamp its power consumption.The valves are trivial to install: you just shove them into the plastic pipe and hoseclamp the buggers in.

author: bostonman
author_rank: Super Contributor
timestamp: July 18, 2019, 06:53:14 pm
content: I briefly looked at doing an entire system myself and seems more than just valves are needed. I saw on Lowes' website that timers and valve manifolds are also needed. Seemed like a more complex system to install than just hoses, valves, and risers.

author: bob91343
author_rank: Super Contributor
timestamp: July 18, 2019, 09:39:40 pm
content: You don't care about wasted electricity; the amount used by a sprinkler system is trivial. As for reliability, if it worries you just turn off a master valve when you are away from home. You can use a timer of course, and that's the most popular method, avoiding remembering and consulting your watch. Some systems even measure moisture content in the ground and water until it reaches some preset level.Automation can be convenient and it can be overdone. Select the level that best matches your personality. Whatever you pick may turn out to be unsatisfactory later on.

author: IanB
author_rank: Super Contributor
timestamp: July 18, 2019, 09:52:30 pm
content: Quote from: bostonman on July 18, 2019, 05:59:58 pmThe solenoid valves may also be used to reduce the supply pressure. The supply pressure directly from the water main may be too high for the sprinkler heads and should be reduced to a more moderate pressure. You will find out soon enough if this is the case as the sprinkler heads may take off like rockets if the pressure is too high.Also as other people have said valves can be used to run just 3-4 sprinkler heads at a time in order to have adequate water flow to each head.Lastly the plumbing code may have anti-syphon regulations you have to comply with to avoid contaminated water getting back into the clean water supply.But fundamentally there is no reason why you can't just manually turn the water on and off rather than using a timer and solenoid valves.

author: bostonman
author_rank: Super Contributor
timestamp: July 19, 2019, 02:23:25 am
content: I didn't feel the sprinkler system used much electricity, but a friend said her son's bill increased substantially after installing a system.Anyway, I think everyone answered my question. First step would be to measure the water pressure, but regardless, it seems the best I'll do is three maybe four heads without any additional equipment such as valves.I looked on Home Depot, and the only specifications I saw were the gpm rating and pressure rating, 8.4 and 50 (psi I assume) respectively.So if I measure my water pressure and it's 90, does this mean I can only use two of these without any valves or is the calculation not that simple?

author: bostonman
author_rank: Super Contributor
timestamp: July 19, 2019, 02:44:19 am
content: By the way, this system from Home Depot shows a straight six sprinkler system.https://images.homedepot-static.com/catalog/pdfImages/46/466e3012-1d45-4964-982a-06cd1e9e68fa.pdf

author: eKretz
author_rank: Frequent Contributor
timestamp: July 19, 2019, 03:07:14 am
content: Geez, 8.4 GPM?! Hope you have a well and not city water. I think your water line is going to have trouble runningtwoof those, let alone 5. Unless you have bigger than 1" main line out to the sprinklers you're going to have some pretty significant pressure drop. And hope you don't want to run a shower or anything while they're on.

author: IanB
author_rank: Super Contributor
timestamp: July 19, 2019, 03:20:05 am
content: Quote from: bostonman on July 19, 2019, 02:23:25 amIf your water supply pressure is 90 psi and the sprinklers want 50 psi then you need a pressure reducing valve to drop the pressure down. Otherwise the sprinklers may consume too much water, may have a poor spray pattern, or may pop their heads off. On the other hand, if you have a manual tap to turn the water on and off you can just adjust the tap to get a good spray pattern. Also, with a higher water pressure you can run more sprinklers at the same time.

author: Dundarave
author_rank: Regular Contributor
timestamp: July 19, 2019, 03:26:51 am
content: The easiest thing to do would be to buy three heads, since you know that’s the minimum you need (and you’re going to need them anyway, regardless of the valve arrangement) then do a quick ‘n dirty connection of all three to your garden hose. Then try just two, etc.You’ll find out pretty quick what the end arrangement is going to need to be from a pressure/water range perspective.A 3/4” hose would be best, of course. I call it “empirical engineering”, lol.By the way, have you considered using one of those rotating heads like they use on golf courses? The ones that shoot streams of water as they ratchet around. Depending on the size and shape of the lot, you could conceivably reach the whole area with a single one stuck smack in the middle.Edit: I just re-read your earlier post, and at a 15 ft. radius, I have to assume these are what you are planning to use.I had a couple in my system, and you can fine-tune range and rotation to fit the borders perfectly.

author: techman-001
author_rank: Frequent Contributor
timestamp: July 19, 2019, 01:21:20 pm
content: Quote from: Dundarave on July 18, 2019, 06:46:34 pmOf course the pressure on the day you test may be higher or lower than normal depending on local water usage in your area.

author: bostonman
author_rank: Super Contributor
timestamp: July 19, 2019, 01:27:05 pm
content: QuoteHahhah I had this thought long ago. While Home Depot will pretty much return anything, I was trying to approach this more methodically because I dislike buying things with sole intention of returning them used.I remember looking at sump pumps at Home Depot and water was dripping out of the boxes. Sometimes I wonder if people have any shame when returning things - this assumes Home Depot didn't just stick legit broken returned pumps back onto the shelf.

author: Hemi345
author_rank: Contributor
timestamp: July 23, 2019, 10:26:05 pm
content: Home Depot used to rent the pressure gauge out for really cheap. Check the tool rental (if your store has one).You need to measure your water pressure and calculate flow rate. There are instructions for how to do this on Rainbird/Orbit/Hunters' websites (here's a link to a video on how to:MEASURE FLOWRATE. The problem with using a hose bib is usually they're plumbed in with 1/2" pipe. The flowrate is not sufficient for running more than one or two sprinklers. Most homes have a dedicated pipe for sprinkler systems of 3/4 to 1" in size. Like others have said, measure your water pressure and flowrate when you see other homes watering their lawns and also while you may be running your dishwasher, clothes washer, or someone is showering.Is the PVC already in the ground or will you be trenching and burying it? If you're trenching and all, it takes very little extra time to plumb in a valve box in the grand scheme of things. Orbit makes some nice and easy to use manifolds that make it as simple as screwing it all together like nuts and bolts:ORBIT MANIFOLDS. I used these 12 years ago when I installed my system (although they didn't have them preassembled with the valves like they do now). The nice thing is they're easily serviceable should a valve quit working. If you really don't want a timer, you can actually operate the valves manually by turning a black knob on the top. Automated sprinkler system adds value to your home and will make it easier to sell should you want to in the future.Underground piping will require you install a backflow preventer/antisiphon device (big fines if you're caught not using one around here). They're $50-100 and nearly all municipalities require one regardless of how you're connecting it to your home's water source.HTH

author: bostonman
author_rank: Super Contributor
timestamp: July 24, 2019, 06:55:43 pm
content: QuoteNothing exists yet. Mainly I'm sick of dragging out a sprinkler or using two ratcheting sprinklers I keep in an ideal spot. Neither methods cover my whole lawn, so I was looking for a quick solution.Since the ratcheting ones seem to have enough pressure, I thought sprinkler heads would have ample.