https://www.familyhandyman.com/landscaping/how-to-winterize-a-sprinkler-system/view-all/

https://m.youtube.com/watch?v=s3YRbJYmvgA

https://www.popularmechanics.com/home/lawn-garden/how-to/a24267/how-to-winterize-your-sprinkler-system/

https://m.youtube.com/watch?v=2607vhyT48Q

Looks like you could get away with a smaller compressor and an adapter from hose thread to quick disconnect for the air hose.

https://www.homedepot.com/p/ANVIL-2G-Pancake-Air-Compressor-with-7-Pieces-Accessories-Kit-0110247A/302862443

https://www.amazon.com/Winterize-Sprinkler-Systems-Outdoor-Faucets/dp/B0055Q6CRO/ref=asc_df_B0055Q6CRO/?tag=hyprod-20&linkCode=df0&hvadid=198097979185&hvpos=1o5&hvnetw=g&hvrand=9700812427432530224&hvpone=&hvptwo=&hvqmt=&hvdev=t&hvdvcmdl=&hvlocint=&hvlocphy=9003353&hvtargid=pla-413829350837&psc=1

Heck, you can do it on smaller systems with a shop vac that reverses air flow.

I know that because I do it every year with a shop vac that reverses air flow. I have eight zones, covering a grand total of 12,000 square feet. It takes a while and a bit of on-again-off-again to get the water all out, but it works.

More info. My irrigation guy (just wrote irritation guy, Freudian slip) operates the zones from the valve box in the ground. If your control panel is in the basement, as mine is, it avoids having to run in and out to run the zones. This explains how to run the zones manually from inside the box. At least on my system.

https://homeguides.sfgate.com/open-rain-bird-valves-manually-91254.html

My guy charges almost $200 to come out. Spring and fall. This summer he charged me $80 to come out and adjust the heads to stop them from watering the street, after I had already asked his guy to do so on a previous visit. (The guy told me the street would dry.). I’m planning on doing this myself in the future. It’s not rocket science, you just have to learn how to do it. I’m educating myself.

Morpheuspa, I’m intrigued. How do you concentrate the air stream from the vac and get it into the system. Mine is only 6 zones. 1.3 acre mostly taken up by house and 2 car garage.

I realized almost this entire post falls under "giggity." Sorry about that.

I borrow my mother's shop vac (ten times better than mine) because it can be switched between suck and blow. I usually start with blowing out the system, and I wrap my hands around the flexible hose connection/solid shop vac stick to seal it as well as I can.

Once it blows out as much as it's going to, I shift over to suck and repeatedly wrap and release my hands until the water's out of the line (when no more is getting sucked out, I figure it's dry enough).

Repeat eight times.

It doesn't take that long, really, and so far it's been a one hundred percent success. All the system damage that's happened has been animal or impact related, not frost and freeze problems.

That’s pretty high tech. I read your whole post with no thought of anything being untoward. Then I looked up what giggity means.

Yeah just do it yourself, Joe. I use the exact same compressor you show, only mine is red. I adjust the pressure to 65 psi as that is what my water pressure is. The issue with small compressors is that they lack the volume of air to blow the lines completely dry. So when you get the initial volume of water out of the line it depressures quickly and the compressor can't keep up. You have to let the compressor repressurize again before you blow out the next line. I blow out each of my 5 zones maybe three times. I could probably do with less but what the heck. If there is some water in the lines it won't cause a rupture. I think the main thing is to be sure that nowhere in the line is there a pipe/tube full of water, like at the bottom of a slope (like you have) where the line turns upward to the sprinkler head. That's why you need to blow out several times. It gives the remaining water time to settle where it wants to before you blow it out again. I've been doing this for about 5 years now and haven't had a problem yet. Saved about $750 so far.

Thank you bud!

Sure thing. If you do us the 6 gal compressor keep an eye on how hot it might get. They aren't designed to run continuously like that, I think.

Received a notice that more comments were in about sprinklers. So, here is my latest. My old 24 gallon compressor died, so I purchased a 30 gallon compressor (7.x cmf at 40 - not a powerful system) and hooked an auxiliary 3/8" x 120' foot hose and connectors for winterizing pool and sprinkler system. Having used a small pancake compressor before (which I still have), I can state that I have made a big improvement. This year, I included my 5 zone front sprinklers (that were normally done by a pro) without issues. I have 14 zones in total. With this system, on average, the sprinklers are blown clear in about 90 seconds for each at 60 psi. Not sure what the end line psi pressure is, but it is enough to blow out the lines. I repeat the operation 2 or 3 times to make sure the water is blown out. I have a Rachio controller which runs from my iPhone and this is a huge benefit. Having the phone allows me to stand near all the zones, start them, and ensure that things are working well. Both front and back systems are wired into the Rachio. I don't doubt that a reversed shop vac can do the job, but I just like knowing what is happening with the pressure gauge. At this point, the only professional service I use is for certifying the backflow preventer in my front system. I have the rear system installed in such a way that certification is not required, according to my sprinkler folks. I think that is because I am hooked to a typical hose bib in back with a backflow preventer also installed. I like compressed air for my pool as well. Primarily because I like the sound of air with no water to ensure that I have most, if not all the water removed from my pool lines. Again, I realize a shop vac can be used for this, but since I have the compressor equipment, that is my primary water clearing source. I do use the shop vac to some extent getting water out of the skimmer box, etc. I'm getting ready to do an experiment and will report the results after I'm done. I'm going to trap water in 1" PVC and Polytube and put it in the freezer to see where the magic burst point is. Will it burst with water half filled? We'll find out. Of course, the real issue is are there any low spots in the lawn where water can completely fill the tube even after most of the water is blown out? In my mind, that is the $64,000 question. Regards.

I only have 5 zones and the little 6 gallon compressor does just fine, if belabored a bit. If I had as many zones as you I'd invest in a larger compressor like you did. Good job! Interested to hear your PVC test results!

If you design your system to have drain valves at the lowest points your don't need to blow it out I also have found that tarp straps are a great way to hang poly pipe in the garage after draining and coiling them.

I mean, water expands but...not that much. Half filled might be an issue, a third filled probably won't be, a quarter filled, certainly not. And if the half filled area has some place to expand into and the hose is flexible enough, no problem.

One hears fun little myths about certain types of hoses getting caked gunk in them from deposits while others don't. It's complete and absolute bunk (source: an irrigation specialist I know, cross-checked with a materials scientist). All hose or pipe types will get gunk in them from deposits if there's an imperfection (and all hose and pipe types have imperfections or will the instant they reach the soil or run for ten seconds and get scratched by the sand in the water).

The only risk is using something that reacts with the water or something in the water, like many metal fittings. Don't do that, of course.

And on the balance of things, in areas that freeze and where you're concerned your irrigation pipes can freeze and are not situated below the freeze line, blow 'em out well, use self-draining lines, or ones that are flexible enough to take a partial freeze when only partially blown out. Drain valves are cheap.

I kind of half-arsedly blow mine out, but the main lines are rubber, the sub-lines are thinner rubber and smaller, and the garden's minor lines are flexible rubber tubing. I've never had an issue and the garden automatically drains out at the lowest points anyway via 1/2 GPH drippers with no pressure regulation (hence, they simply drain the lines).

Why do frozen pipes burst? They talked about this on NPR a week or so ago. Apparently, perhaps surprisingly, freezing pipes don't burst because of ice expanding in place. Instead, they burst because the water expands along the length of the pipe causing pressure to go up. If the faucet is closed, it can go upwards of 200 psi which splits the pipe. If the faucet is open then the pressure cannot go up.

With this in mind, I wonder if underground pipes with open sprinkler heads need to be blown out at all?

Picture it. Sicily, 1912... :-)

But seriously, picture it, two bolides* of water between two sprinkler heads, pushed like pistons between two freezing ice heads, compressing the water and air in the lines between the heads... The air at least will compress. Water just pressurizes.

I've seen problems with systems that haven't blown out, and had occasional issues in the gardens before I installed the drains at the lowest points (fortunately, in the gardens, incredibly cheap and easy to repair). The pipe swells like an aneurism, detonates, and that's that.

* Somewhere out there, a grammarian is currently starting a thread that will last seven years on how I've misused this word that will include numberless people with no academic credentials who never bother to use a dictionary being incredibly nasty and throwing the epithet "troll" at anybody who dares to actually use a dictionary. Also, the proper plural of "bolide" is "bolides," and the singular of "bolides" is not "bolus" in English. In this case, I more mean "bolt of lightning" as the original Greek, since that's about the effect on your pipes if they break.

On my system, the main lines are PVC buried well below the frost line and with multiple drains including one about 5 feet lower (yard is very sloped) than the rest of the system. Draining them is all I need. The above ground lines are poly and those are gravity drained, coiled and stored.

Each valve has a filter on it and a air brake(can't remember the correct term) on each line.

Sounds like we need the pro's on this one. I agree that the freezing issue is likely over-rated, but having had a backflow preventer burst and sending a stream of fire-hydrant-like flow across the lawn until I was called by a neighbor taught me a lesson. Don't recall how it happened, but it did. There were no problems until things thawed. Fortunately, the damage was confined to a replaceable part on the backflow preventer. I have also seen failures with automatic drain valves. When working, they are great. When not working, they ain't worth a crap. The problem is you don't know when they are not working. I started the test freeze project, but half-assed so far. I filled a plastic orange juice bottle with about two thirds water. and laid it on it side in such a way that only half of the neck was filled. No damage to that one but the volume increase was surprising and significant. Frankly, I was surprised that the neck did not fracture, but it still had a very slight bit of wiggle room in it. How much elasticity is in the plastic? I'm betting virtually none when frozen. Next will be a full bottle of water in a plastic pop bottle. If it breaks, then I'll start reducing the volume by an accurate percentage. Finally, while we are at it; one more. If all the icebergs in the ocean melted, will the ocean level rise, fall, or stay the same? There has to be a scientist on here somewhere. :-) Have a great evening.

dchall said: With this in mind, I wonder if underground pipes with open sprinkler heads need to be blown out at all?

Yes, I think they most definitely do! Water doesn't always freeze in a neat, orderly fashion as it might in a laboratory. For instance, if you get an ice plug at the 90 where the PVC makes an upward turn to the head then the water behind the plug has nowhere to go. Also, think about the possibility of supercooled water in the pipe. Have you ever put a bottle of water in the freezer and then very gently taken it out before it freezes? If you catch the water at the right temperature and then give the bottle a little shake the whole thing will freeze in a matter of seconds. I could imagine something like that happening when a truck rolls down the street vibrating the water, or maybe an overactive squirrel! The trick with supercooling is that the water has to be very still until you shake it to trigger the freezing process. Anyway, just a thought.

Ok, good examples. Question answered.

"If all the icebergs in the ocean melted, will the ocean level rise, fall, or stay the same? There has to be a scientist on here somewhere. :-)"

Been there, did this for a chemistry class. It was more a density calculation, but I don't quite think they expected any of us to do the expansion coefficients at various temperatures.

It depends on the ocean temperature that results as water has a density of 1.0000 at 4 degree C. Density drops above that (the water expands). It's 0.99987 with water at the freezing point, and of course, it becomes about 0.9 as ice.

So the water volume resulting from the ice is actually relative to the water it's melting into--usually pretty cold, under 4C, but that's not always true (they've been spotted even into the tropics after very stormy conditions).

Generally, the water, at least initially, is of greater volume than the iceberg it's coming off of. Over time, as it warms, it will be the same, but that takes some time to equalize, although the volume differential is very slight (rarely more than 0.02%). However, we cannot ignore that if we wish to be exact.

For icebergs in the tropics, the water melting off could be up to three percent different.

Most people will simply give the answer "it stays the same," given basic displacement, which is acceptable, given the relative addition of the small amount of water contained within free-floating icebergs at any given instant. We've just seen it's not quite so simple and water of various temperatures is actually of different densities.

However, overall, there simply aren't that many icebergs, and they're already displacing water. Even with a theoretical three percent differential, which you aren't going to notice in the real world when standing on shore, we can confidently state, "The ocean level will not visibly change." Even though, in reality, it actually does rise a touch more than one might expect if one could measure accurately enough both for the density reason and for one other--gravitational attraction. I discuss that a bit below.

Note: This only works for icebergs ("a large floating mass of ice detached from a glacier or ice sheet and carried out to sea"), a la "ICEBERG! RIGHT AHEAD!" Poor sods.

If you mean glacial sheets, there are actually many considerations here. The sheet can be grounded, floating, or partially floating and partially grounded (Antarctica's Ross Ice Shelf exhibit all three characteristics), so the amount of rise depends. Fully grounded ones will increase ocean rise far more than floating ones, where the rise is only from the expansion of the water.

...Or so it would seem. However, the ice shelf itself contains mass. The Ross Ice Shelf is the size of France. Observed as a gravitational anomaly (and we've done so), it actually attracts water (and atmosphere) to itself, which begins to "relax" back into the ocean (and air) as it melts, increasing ocean depth just from the water flowing back as it's no longer attracted to the mass of the ice and begins to flow back into World Ocean proper.

...No, I'm not nuts. It's an amplification effect. Minor, but there, and it does have to be accounted for when you have country-sized masses of ice moving about on your home planet.

If it all melted and redistributed its mass (you'd end up with a bit more of that bulge heading for the Equator due to rotational and, again, gravitational effects), you'd end up with, on average, a 230 foot ocean rise or so. give or take 30 feet or so (we're not entirely sure how much water there is and it depends on the water temperature again since warmer water expands more).

But that requires an enormous amount of energy and, unlike freezing, phase changes are constant. Superwarming doesn't happen and you won't get a wave of melting, unlike supercooling and a wave of crystallization.

Holy cow! Thanks morpheuspa! I knew my Kentucky Bluegrass was going to thrive after your helpful suggestions. Now I know why. My dad always said I had a problem: "I was always broadcasting when I ought to be tuning in". Once again, he was right. All that aside, I find your article fascinating. Most folks, including myself, likely don't realize, or even understand, what temperature and chemistry adds to the statement that icebergs are melting and the oceans will rise. I've always thought it would be insignificant. But I can see, as you mention, when land ice melts, that is a different issue, although once again insignificant if I read you right.. Very interesting. In the meantime, attached is a photo of my 2nd orange juice container that was filled completely with water (1/2 teaspoon bubble left) and placed in my freezer. As you can see, the bottle did not break. It's now in the sink so I can see what it looks like after the ice has changed back to liquid. Of course, an orange juice plastic bottle is not PVC or poly pipe. I'll bet if the bottle were glass, I'd have a different picture. I'll report more soon. Learning more about this stuff is not only fun (magical chemistry tricks), it's interesting, at least to me. Then when an underground sprinkler pipe breaks from freezing, we can scratch our head and say, "what the heck" is going on here? Of course, that's before the need to get your work pants on or phone the expensive repair folks. Now that the plastic bottle did not break, at least in the frozen state, I'm even more curious about what will happen to Schedule 40 PVC. Doggonit dad, now I'm curious about my pressure cooker. :-)

Also, thanks to danielj_2009. Another bit of interesting information.

Ooops. Forgot the picture. Here it is.

So far, the bottle seems to be containing the ice quite well. My grandfather and I used to play this game...more years ago than I care to think about, actually. :-) We did it in an aluminum pan that was no longer good for heating things (it leaked). We never did get the pan to blow out of the sides because it was slightly pitched to open toward the top.

Because of the shape of the bottle, you might if you can trap the frozen cap of the water under the curve of the neck and pressurize the water as it tries to expand (but can't) up the shrinking sides of the neck of the bottle.

Although the plastic might be a little too flexible.

Of course, you could just put the cap on. That'll do it. :-)

Why not use a shop vac and suck instead of blow?