How to blow out inground sprinkler lines

I Just had in ground sprinklers put in this spring, now that the temperature has dropped I have to blow out the lines but I dont know how, Does anyone know how to do this? The only thing i do know is that i need a compressor which i do have (15gal 150 psi) Thanks in advance.

Reply to
gperez234
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Do like I do, have the folks that installed the system come out and do it. (mine charges $60) A lot cheaper than blowing out a line by over pressurizing.

Reply to
Patch

Unfortunately your 15 gal compressor just isn't going to do it unless your system is extremely small. You need a lot more volume than what that can provide. The guys that I've seen do it use large, truck mounted compressors with a very high volume. Did they install automatic drains on the lines when they installed it? Cheers, cc

Reply to
James "Cubby" Culbertson

How about a shop vac?

Suck the water out for each valve "circuit" at the lowest sprinkler head for that circuit.

A hundred feet of 3/4 PVC pipe holds about 3 gallons.

I use a shop vac all the time when I work on a sprinkler system (I use it to suck out any dirt that might have gotten into the pipe when changing a riser....saves having to clean or replace the sprinkler spray.

you only have to get enough water out such that the pipe is nowhere completely full.

cheers Bob

Reply to
BobK207

Never have blown them out. My neighbor has someone do it each year.

Near Denver. Have been through -15 degree periods without a break but with out dry climate the water in the lines probably evaporates.

I risk a break but in 30 years with two systems at two different houses. I have never had a broken line. I have drains in the valve boxes and of course at the turn on valve. Mine turn on valve is about 5 feet underground. One of those valves that when you close it a check valve opens and back drains from the anti-siphon that is above ground. Then the drain in the boxes take care of the other side of the anti-siphon.

Reply to
Rich256

Well, that is the trick. There are definitely going to be high and low spots in the underground line, and the low spot would only have to be an inch or more lower than the pipe on either side for the pipe to be full at the low spot. Settling on getting out most of the water is taking a risk. You might win, you might not. It's safer, easier and cheaper to blow out the system than repair a burst pipe.

R
Reply to
RicodJour

I do mine every year with an old Sears compressor, maybe 10 gal capacity, delivers 6.4CFM@40 I added a gate valve and male air fitting on the water supply side.

I let it get up to about 70PSI, then turn on the zone. I go through all the zones twice.

It's true that more capacity will do it faster and probably get a bit more water out. However, I've been doing it 8 years and can't attribute any problems to freezing. And I've saved $500.

Reply to
trader4

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