Its green now, but the far area of my backyard used to be brown, spotted and ugly. This was because my expanded landscape had too many sprinklers, and the only pipe to the area turned out to be too small to supply the needed water. To complicate matters, the central station controller and valves were located next to my house and were fully surrounded by a large concrete patio slab that was poured over the previously installed irrigation lines.
The existing thin-walled, 35-year-old PVC pipe was very fragile and was at risk of rupture or blow-out if exposed to long periods of full supply system pressure. Additionally, there was no electricity available in the remote zone. Therefore, connecting the main water source directly to the existing pipe in order to feed remote branching valves was not an option. No doubt, at this point many of you may be thinking; "This problem is similar to some I've encountered." If so, read on for a simple fix.
After surveying the many products available in the marketplace, I found that remotely located 'wireless' battery-operated valves with mating controllers could be arranged to do the job very effectively, Figure 2. By adjusting the central timer to increase the run time on the existing supply pipe and coordinating it with the new remote battery-powered valves, I could water the entire area, each branch sequentially, while preventing full pressure in the old pipes when they were not in use.
An example of how this works (Ref. Figure 2): Set the battery timer to turn on Branch 1 at 6:00a.m. and run 30 minutes. Turn on Line 2 at 6:30a.m. and run 30 minutes. Set the original central timer to activate the existing line valve at 6:05a.m. and run 50 minutes. This provides 25 minutes of watering on each branch, with a five-minute grace period at both the cycle start and end to allow for slight timer errors, thereby ensuring no high pressure reaches the old pipe.
Battery-powered devices are readily available either as separate controllers and solenoids for installation into various brands of user-owned valves, or as complete kits including valves, solenoids and controllers. The branching setup depicted in Figure 2 shows a Hunter model SCV attached to two latching solenoid valves. Other battery-operated models by Nelson and Rain Bird are shown in Figure 3. Several other manufacturers, including DIG and Irritrol, supply battery-operated controllers and solenoid valves as well.
While battery-operated valves with controllers are somewhat expensive for the small operator or homeowner, the cost and misery is low compared to that of cutting concrete, trenching through mature landscape and adding long new pipes or electrical wires. Obviously, a minimal amount of trenching is required to create branch connections in the existing zone, but not anywhere near as extensive as installing new lines.
Adjustment of timer settings is a little awkward in remote zones, and making sure batteries are functioning is somewhat of a nuisance. Improper timer settings, battery failure, or interruption of central station power could cause the central valve to open while the remote valves remain closed, thus applying full pressure to the old line. Even though the new latching solenoid valves dramatically improve battery life, it is important to regularly monitor timing and battery status to prevent accidental high pressure application to the old fragile line.
The preceding description of timers and valve arrangements gives users a simple and fairly reliable solution to fix a poorly functioning remote zone. However, in an effort to find an even better method, I've designed and tested a simple and fail-safe non-electrical device that eliminates timing coordination problems, battery life annoyance, weak line rupture concerns and it is less expensive. This is still in development, but is expected to be the subject of another article in the not too distant future.
In the meantime, install the wireless battery-operated devices and get that problem zone green again.