Using a scuba cylinder as an air source to blow out irrigation line for winter?

[Matt S.]

I need to blow some water out of a buried irrigation line.

I don't have a compressor but I do have scuba cylinders. I'm sure this is possible, but I'm not sure where to start with the adapters etc. Has anyone done this?

 

[Cave Diver]

There are blow gun style adapters available that will fit the quick connect on your Low Pressure hose. Check with your local dive shop, or an online retailer. Shouldn't be hard to find.

 

[whaylonsmithers]

Low pressure air is ~140psi and duct tape will hold hoses together against that. Method 1 - cut the end off a low pressure hose and duct tape it to your irrigation line. Method 2 - unthread the core of the shraeder valve from your low pressure inflator, jam it in and tape it up. If the diameter is greatly different use a bit of hose in the middle as an adaptor.

I don't have a clue whether this will damage your irrigation line or how much air it would take to do the job. I've used it to inflate zodiacs, no idea of its application to irrigation line.

 

[Matt S.]

I did some reading on this subject. When pros blow out irrigation lines, they use about 65 PSI but a very high volume compressor.

My irrigation line is rated for 200 PSI, but I don't know if the junctions are good for that. So, I'm not sure if this approach is safe for my system.

You can get an add-on regulator for an air compressor for $20 so it would be easy to reduce the pressure... but that dinky reg doesn't look like it will pass a lot of volume.

I'm more confused than when I started.

 

[Peter_C]

You can also flush with water pressure, which should be up over 50 psi if it is on city water.

I keep one of these Global Manufacturing BCD Coupler | Dive Right In Scuba - Plainfield, IL connected to a blow gun for inflating my boat if needed out on the water. Vacula 72-020-1050 4 Full Flow Blow Gun : Amazon.com : Automotive

You can use whatever blow gun you want though.

120psi in PVC pipe shouldn't hurt them. Do be careful though as when they blow...they BLOW! Some people use them for airlines, but it is not recommended and OSHA frowns upon it.

 

[Superlyte27]

I've done this. I just remove the second stage from the hose, stick the hose in the line, duct tape if necessary (which isn't necessary for my application) and turn on the tank. You can regulate 0-140psi depending on how much you open the knob on the tank.

 

[Rooster59]

I blow my 10 zone system out every fall with a garage compressor. However you cobble it up should work ok, but do not let the psi in the irrigation system get higher than maybe 50 lbs or so. There are valve parts and flex hose connections that can not take the full 145 psi off the LP ports of your 1st stage. You need to open the zone / run / whatever you call it and then add the air. Don't add the air to a closed zone as bad things can happen fast. Add the air slowly at first and let it push the water out, the commercial guys use a high vol compressor cause they're in a hurry and on the clock.

 

[Matt S.]

After talking with some locals I ended up not doing anything at all. My line is buried 24" deep, and guys around here with 18" systems dodge the freeze. So, I think I will be OK. I'll find out in the spring!

 

[Rich Keller]

If the pipe is fully open at both ends you could just put a pig in the pipe, a foam ball should work well enough. The air pushes the ball and in turn the ball pushes the water out. This is far more effective then just using air alone so you would be able to do this with a tank instead of a compressor.