We attach an air compressor and air hose with attachment that is threaded into the back flow test port. After turning off the isolation valve, we systematically turn on each valve and blow it out, move to the next one and so on. Always be aware that the PSI does not go above 80 PSI. The air compressor does have a PSI gauge.
Blow out sprinkler linesIn general we blow out a zone with sprinkler heads first, this speeds up the process of getting the water out of the main line. Blow out spray zones until they are dry. Take care not to run the air compressor too long with no water in the pipe. Friction from the air can damage pipe and/or sprinkler heads by heating them up or making the rotors sprinkler heads oscillate too fast. Once you have competed at least one spray zone, then move onto the drip zones.Never run the air compressor with no zones open!!!Disconnect the air hose. You will get some back pressure from the air that has been pumped into the pipes.Make sure to drain the mainline pipe from the back flow to the isolation valve. Most isolation valves use a “stop and waste” valve for this purpose. Open the lower test cock or the first one on the inflow side of your back flow (it should be tapped into the ball valve). Once this is open, listen for the draining of water out the “waste” port of the stop and waste valve. Or look into the stand pipe and see if it is wet from draining out already. Sometimes the waste ports get clogged with dirt or roots grow into them and do not allow for proper drainage. This will cause severe damage to the pipe and back flow once we get freezing temperatures.Once this is all done. Turn the two ball valve handles to a 45 degree angle or halfway open and leave the leave the test cocks open.It is vitally important to leave the valves open and slightly turned. It keeps the valves usable for future use. They can become hard to turn and if you are moving them twice a year, this helps them from locking up. Also, if the isolation valve is bad and leaks, the water will drip out the first open test port. The leak could be so small that is may take weeks for it to fill up the mainline and leak out of your open test cock. If you don’t notice leak, then only a small part of your back flow will be damaged instead of the entire back flow and piping. That would equal a big repair bill!!!We can provide this service for you. Click here for more info.
Winterizing without an air compressor
If your system was originally designed to drain using gravity, then this is the easiest and cheapest route to winterizing. Essentially you are draining the pipes using the power of Mother Nature. Each system will have it’s own unique process to guarantee that all the lines are dry.
Steps for winterizing by using gravity
Close the isolation valve. Open all the test cocks on the back flow. Open all the drains located throughout your property. This may be a problem if you have inherited the system from a previous owner. Once all the water has stopped draining. This could take up to an hour. Close all the drain downs, turn your ball valves to a 45 degree angle on the back flow and leave your test ports open.As always, AZ Irrigation & Maintenance is here to help you. Please call or click to get us real quick!