Automatic Drain Method

This method is recommended when the automatic drain valves are located at the low and end points of the irrigation piping. In this case, if the pressure in the piping is less than ten PSI, these are automatically going to open and drain the water. Activating these is easy and you just need to shut off the irrigation water supply and then relieve the system pressure by activating a station. At this point the mainline will be empty, so make sure to open the drain cap or the boiler drain valve on the waste and stop valve and drain the water between the backflow device and the irrigation shutoff valve. Next, the test cocks on the backflow device should be opened. If you have sprinklers that come with check valves, it’s necessary that you pull up on them so that the water drains out at the base of the sprinkler body. Based on where the drain valves are located, there might be some water left in the sprinklers, piping and backflow. Depending on the area, there could be a mix of the automatic drain system on the lateral lines and the manual drain system on the mainline.

Manual Drain Method

If the manual valves are located at the low points and end points of the irrigation piping, then using this method is highly recommended. To drain such systems you just need to shut off the irrigation water supply and then open all the manual drain valves. Once the water in the mainline has completely drained, make sure to open the drain cap or the boiler drain valve on the waste valve or the stop valve and ensure that the remaining water is properly drained. Next, you’ll need to consider opening the test cocks on your backflow device. In case your sprinklers feature check valves, you have to pull them in order to make it possible for the water to drain out the bottom of the sprinkler body. Based on where the drain valves are located, it may be possible that there’s water left in the sprinklers, the piping and the backflow. Once the water has fully drained out, you need to ensure that all manual drain valves are properly closed.

Blow-out winterization don’ts:

If you plan on using compressed air in order to blow-out the system, then it’s very important to wear protective attire, such as gloves and eye protection (ANSI approved). When blowing out the system, make sure to not stand over any irrigation components (valves, sprinklers or pipes). By not following these rules, you may get injured during the process. Other things to be aware of when blowing-out your sprinkler system include:

1. Ensure the pressure doesn’t exceed fifty PSI for systems with polyethylene piping and eighty PSI for systems with PVC piping.
2. After the blow out is over, make sure you don’t leave the manual drain valves open.
3. Don’t blow the system out through a pump or backflow. It’s recommended that the system is blown first followed by draining the pump or backflow.
4. Never leave the air compressor unattended.
5. While the system is pressurized with air make sure to not stand over any of its component parts.