More than just opening a valve, Art Elmers, CIC, CID, CLIA Netafim USA. Even though snow still surrounds us, we know that one of the busiest times of any irrigation contractor’s year is just around the corner for turn ons. As soon as warmer weather and buds on the trees arrive, phone calls from anxious customers start to pour in. From a cash-flow standpoint, spring is the time of year all irrigation contractors love. The temptation exists to squeeze in as many system turn ons as possible and maximize that cash flow. However, we must all remember that in this competitive world, doing just the minimum for turn ons might not be enough.
We all must remember that in this competitive world, doing just the minimum might not be enough.
In simpler days for turn ons, just showing up, opening a valve and running quickly through the zones was enough. With today’s irrigation systems and the push to conserve water, irrigation contractors must be prepared to do more. This article lists the basic, minimum steps as well as other things that can and should be done when turning on an irrigation system. The first step has always been and should be the opening of the irrigation supply valve. This should be done only after any open drain valves and backflow preventer test ports have been closed. The key here should be to open this valve slowly. Remember speed kills and sending water down a pipe at high velocities has the potential to break fittings and pipes. In fact, more pipe and fitting breaks occur during the turning on of the system than from freezing during the winter. How slowly should the valve be opened? For most residential and small commercial systems with pipe sizes under 2 inches, just open the valve approximately one-third of the way. You should hear water rushing down the pipe. After a few minutes the pipe will be filled with water. If you are unsure, just look at the water meter to see whether it still is spinning. After the pipe has filled, open the supply valve fully.
Turn ons for larger systems – pipe sizes 2 inches and larger – it is good idea to crack open the irrigation supply valve earlier in the day or even the day before, then return to complete the turn-on service. This allows the main lines to fill up properly without having service people standing around. In all cases, listen to the pipe after it is filled. If you still hear water moving, check for a stuck valve or break. It is important to note that backflow preventers now are required in most locations by code. The local codes also dictate how often these devices must be tested. If they need to be tested annually, the spring turn-on is a good time. But beware, in most cases a licensed backflow preventer tester must be used. If you are one, fine, but if not, make arrangements with someone who is.
While the pipe is filling, it is time to check out the irrigation controller. If it was unplugged for the winter, plug it back in. Replace the program backup battery if the controller uses one. Re-enter the correct time, month and day settings as needed. Set the irrigation schedule, and be sure to put the appropriate percentage on the seasonal adjust feature. If you schedule the clock for August irrigating, make sure to set the seasonal adjust to approximately 33 percent for April, 66 percent for May, 88 percent for June, 100 percent for July and August, 88 percent for September, 66 percent for October and 33 percent for November. Be sure to check for any additional start times or programs and remove them if needed. With an electrical multi-tester you also have an opportunity to check the health of the field wiring and valve solenoids. By checking the resistance through each zone you can spot potential problems. The resistance reading for normal systems should be 20-60 ohms. Higher readings start to indicate a bad splice or damaged solenoid. The circuit may operate now but has a good chance of failing in the near future. A low reading of below 5 ohms indicates a short circuit. If it only is on just one zone, more than likely you have wires touching or a blown solenoid. If you have a very high reading above 100,000 ohms, then you have a break in the wire or solenoid. If you see this reading on all zones, check the rain sensor to see if it is on. Testing circuit health is usually above and beyond a simple turn-on but can help set your company apart from the rest.
Now that the main line is full, the supply valve fully open and the controller turned on, it is time to check the zones. From the controller turn on each zone. What are we looking for? First, did the zone turn on? If yes, check to make sure each head has popped up and is performing properly. Adjust the heads for pattern, arc and throw as needed. Replace any clogged nozzles, being sure to maintain matched precipitation. Raise and or move any heads now restricted by plant material.
What else can you check for? Lower any heads that may heaved in the frost and make sure that all heads are level. Clear any build up of grass around the head.
If the pressure seems low, look for either clogged basket screens at the head, broken lateral lines or partially closed flow controls on the valve. If you must replace any heads, be sure to replace them with the same model or at least ones that have the same nozzle gpm and performance.
For any drip zones be sure to check and clean the filter if needed. Uncover an emitter at the far point of the drip zone and make sure water is coming out. Rebury any drip tubing that may have come up in the winter and check for any puddles, which may indicate a cut tube.
Record any observations (resistance, etc) and any changes for billing purposes and your records. Your goal should be for you to leave the irrigation system in good efficient working order. You may also wish to call the customer a couple of weeks later to check on any problems or questions. You will be surprised at how many referrals you can obtain from this follow up.
By following these steps you can be assured that you have provided a good turn on.