What is Manage by Flow?
Manage by flow is a feature in BaseManager that optimizes the number of stations that can run at once. This feature is useful for sites that need to irrigate within a certain drought compliance window, or sites that want to irrigate for as little time as possible. It can be used on the BaseStation 3200S and FlowStation, with this article detailing use on a 3200S. For information on using manage by flow with a FlowStation, see Setting the Mainline to be Managed by Flow.
When to Use Manage by Flow
Manage by flow is an essential feature for any sites that run multiple stations at the same time. Without manage by flow, a site risks concurrently running too many stations and losing pressure or causing damage. For sites with drought compliance windows, manage by flow is an important feature that ensures your entire site can be irrigated optimally during the specified window. Finally, if you are irrigating a site during business hours, manage by flow cuts down the length of the site irrigation process without reducing the quality.
How Does Manage by Flow Work?
Manage by flow uses the learned or designed flow of stations and adds them up to reach the total amount of designed flow for the mainline. Manage by flow is designed to not exceed the maximum flow for a system while ensuring the maximum number of irrigating stations. Manage by flow is not designed to exceed your controller concurrent zones setting. When a program starts, the design flow for zones with priority (Primary zones) are checked first, then the remaining zones are checked. Zones are checked one at a time, in ascending numeric order. The controller checks the zones design flow in ascending numeric order until the mainline design flow has been met, the controller or program zone concurrency has been met, or there are no more program zones available to check. When a watering zone starts a soak cycle or completes its watering time, the remaining program zones are checked again until one of the previously mentioned conditions is met.
Example Scenario
Your site's mainline has a designed maximum flow rate of 100 gpm. This site has 6 stations (Or zones) in a program, listed in the table below. Here we assume all stations have the same runtime and program/controller concurrency is not a limiting factor.
| Station 1 | Station 2 | Station 3 | Station 4 | Station 5 | Station 6 |
| 25 gpm | 50 gpm | 0 gpm | 75 gpm | 20 gpm | 30 gpm |
In this scenario, the controller will water stations 1, 2, 3 and 5 concurrently. Station 4 is skipped because adding it to water with stations 1, 2 and 3 puts us over the site mainline designed flow rate. Station 4 then runs, then station 6.
Warning!
If a station has a learned/design flow value of 0, this can cause too many concurrent stations watering and result in pressure loss or hydraulic damage. You can change this 0 value by running the learned flow setup procedure, which will calibrate the correct amount of flow for each station.
What happens if Manage by Flow is disabled?
If manage by flow is disabled for a site, the controller will turn on the stations in their listed order, up to the total number of concurrent stations allowed. This can cause pressure loss in the system if the amount of flow required for the stations is more than the amount of flow the mainline can supply. Loss of pressure can lead to the system not operating correctly. Issues can also arise when using a pump on a system without manage by flow, where damage to the pump can occur if the stations draw more water than the hydraulics can handle.
When not to use Manage by Flow
If you are doing a wet check on a site, we recommend manually watering the sites in the specified marching order instead of using manage by flow. For sites where you don't want more than one station to water concurrently, we recommend disabling manage by flow as well. Otherwise, manage by flow is a key feature for most systems.