MAGIC RAIN L.S.S., Inc.
Post Office Box 364, Hinckley, OH 44233
(Serving Cuyahoga, Medina, Lorain & Summit Cos.) Phone: 330-220-RAIN (7246) and 330-220-9246 email: sandra@magicrain.com
Winterizing Your Sprinkler System
MAGIC RAIN utilizes commercial tow behind Air Compressors
For the Do-It-Yourself Winterizing Clients
Winterizing Your Sprinkler System
Each Fall, it is time to get serious about the winterization of your Sprinkler System. The Winterizing concept seems simple enough to perform. However, it may not be as simple as it may first appear. This must be done correctly to assure there are no costly repairs and replacements required in the Spring when it is time to start your Sprinkler System back up (Spring Turn On).
Winterization primarily consists of purging ALL water from your Sprinkler System and equipment. This is necessary because water freezing during cold weather will break pipes, valves, sprinkler heads, pumps, fittings, etc.
Most materials contract as they get cold. However, here in Northern Ohio, when water cools, it contracts only until it reaches a temperature of 39 degrees Fahrenheit. Upon further cooling to 32 degrees Fahrenheit, water expands as it turns to ice. Water expands and increases in volume by one-eleventh, so 11 cubic feet of water will form approximately 12 cubic feet of ice. This expansion force is sufficent to cause pipe and fittings to burst, valves to crack, and sprinklers and pump cases to split open.
DRAINING YOUR SPRINKLER SYSTEM
Draining the system may be accomplished by the use of your automatic drain valves which rely on gravity to drain the water from the system. Of course this relies on a properly installed system laid to grade with no humps in the polyurethane pipe to trap water in low areas. Also, with electric valves in your System, there is no way to drain the water off the top of the diaphragm of the valve. As this manual gravity draining happens underground, there is no way to be sure that enough has been drained to prevent freeze damage. The only positive way to be sure enough water has been expelled from the system is by using compressed air to "purge" the water out.
The most important thing to remember when purging your system for winterization is that AIR VOLUME and not AIR PRESSURE is the most critical element. If an insufficient volume of air is used, after having forced some water out, the air will ride over the top of the water. This will result in the remaining water draining into low spots and subjecting your system to freeze damage. Ideal pressures are in the range of 55 psi to 80 psi for the air compressor with 80 psi being the absolute maxiumum. Too much pressure is NOT a good thing!
Also a reminder to those with MICRO IRRIGATION.....you will NOT want to use this much pressure. Your Micro Zone(s) are located on a totally separate zone of your Controller Unit. Be sure to use caution. Micro lines are much smaller in diameter, and if the PSI is too high, you will not only purge the water, but you will also purge your micro tips.
RULE OF THUMB If the sprinkler heads remain UP after the water is blow out, you are using the RIGHT size compressor.
The idea is to "purge" your Sprinkler System out using only the volume of air equivalent to the maximum gallons per minute (G.P.M.) for which your system is rated. In other words if you normally run one zone at a time when irrigating, you should blow out in the same way. If you try to do more, the excess velocity of flow and added friction will heat up the pipe and fittings to a point where they possibly could melt. If the pipe and fittings do not burst during this operation, they will be damaged and their life greatly reduced. As a result, failure will occur sometime in the future.
Start with the backflow presenter (or pump if your Sprinkler System includes one). Usually a stop and/or waste valve is used for this. This stop and waste valve is designed to drain the water from underneath the inlet of your backflow preventer. The rubber seals inside can easily melt from the heat of the air.
You will need to turn off the water to your Sprinkler System (this is a separate valve that tees off from your home's water main - located in close proximity to same - Be sure NOT to close off your Home's water main in error).
Drain your pump, remove it from the system and store inside. If this is not possible, the next best thing is to drain the pump and wrap it to insulate from the weather.
HERE ARE SOME ADDITIONAL WINTERIZATION TIPS:
If this is something that you do NOT do on a PROFESSIONAL BASIS, we recommend that the system should be blown out twice to make sure all the water is purged.
Don't use too small an inlet for your air line. The smaller the hole the faster the air has to travel through it and the more heat produced; for instance the test cocks on your backflow preventer are 1 1/8 or 1 1/4 inch. In a normal residential system, this would be the minimum size inlet you would use. A larger inlet would be needed for larger systems.
After purging the system, leave all the valves on your backflow preventer half open. This will help keep the backflow preventer from freezing and splitting during the winter.
If possible, tie into a metal fitting to help dissipate some of the heat from blow out.
With an Automatic System (Controller Unit), your Controller should remain powered during the winter. Heat from the transformer can help keep moisture down and protect components in the Controller from corrosion. The Controller should be programmed to run through a minimum cycle once a week to help keep solenoid plungers from sticking.
FINAL THOUGHT
It is very important to remember it is much less costly and much less labor intensive to properly and efficiently winterize the System in the fall than to repair damaged fittings, piping, valves, sprinklers and other components in the Spring.
Additional Note: We do have some Clients that like to winterize their own Systems. This is absolutely fine. However, please be aware that a 5HP air compressor is simply NOT going to provide the VOLUME OF AIR that a Commerical Unit will. In order to PROPERLY (safely and effectively) winterize your System, we recommend that you follow the procedures as listed above.
If you ARE (or have been) using a 5HP compressor, and although your System APPEARS to have survived the Winter, we have seen System damage that was "progressive" over the following years (having started out as mere hairline fractures BENEATH the ground, and eventually, surfaced). The components aren't always a major to replace (although, it DOES come at a cost to replace these parts and/or the need to REBUILD a manifold box).
However.....polyurethane pipe hairline fractures, literally, will continue to spread, the pipe falling apart (and your 50 year warranty voided due to IMPROPER WINTERIZATION). We can dig up, cut out, & repair the line in that area. But too often (once found), the irreversible damage may, eventually, be found to be System wide.
The only way to CORRECT progressive hairline fractures of a System in which the polyurethane pipe is falling apart is to RE-RUN all the lines (basically installing a NEW System).
Your System has been an investment. PLEASE be sure to winterize properly.
