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Irritrol OmniReg® Pressure Regulating Module Valve Option


The OmniReg® module is a add-on option for some models of Irritrol valves. It turns a standard valve into a pressure regulating valve.

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The OmniReg® module is an add-on device that fits on some Irritrol valves. It turns the standard solenoid valve into a pressure regulating valve. A pressure regulating valve maintains the downstream pressure at a constant level. The OmniReg® module will keep the output pressure within 3 psi of the level you set it at. Of course, the outlet pressure will never exceed the inlet pressure, the regulator can't add water pressure (you need a pump for that).

To install the OmniReg® module the solenoid is removed from the valve and the OmniReg® is installed in it's place. The solenoid is then reinstalled on the side of the OmniReg® device. While Irritrol states that the inlet pressure at the valve must be at least 10 PSI higher than the outlet pressure you set, I suggest that you allow for 15 PSI difference. At lower pressure losses the regulator tends to not be as accurate or may not work at all. For design purposes you should assume that the pressure loss through the valve will be at least 15 PSI if you are using the OmniReg® module, regardless of what the pressure loss table for the valve says. So if you want to regulate the pressure after the valve to 50 PSI, the pressure at the inlet to the valve will need to be at least 65 PSI for the regulator to work properly. By the way, this 15 PSI pressure drop requirement is true of all pressure regulators, not just the OmniReg®. The hydraulic principles of how a pressure regulator work require the pressure difference. Fortunately, if you don't need to reduce the pressure by 15 PSI or more, then you really don't need a pressure regulator anyway!

The OmniReg® module does not work if the flow through the valve is less than 1 GPM. The OmniReg® module has a dial on it that is used to adjust the pressure level. A standard Schrader valve on the side of the module allows a pressure gauge to be attached to the module to check the pressure.

Why would you need the OmniReg® module? There are two situations where a pressure regulating valve are helpful. The first is when you have a system with different types of sprinklers or drippers that each require different operating pressures. You would design the system to provide enough pressure for the highest pressure needed, then install pressure regulating valves on the parts that need lower pressures. An example of this would be a city park. For large lawn areas you might have a large radius rotor sprinkler that requires 60 PSI of pressure. But you might have a small planter area that needed spray heads that fog at pressures higher than 30 PSI. So you would install pressure regulating valves on the spray head circuits to keep the pressure down around 30 PSI.

The other situation where they are used is when you want to design a system with very high pressure losses in the mainlines. This would be the case if you wanted to use a smaller pipe size than would normally be needed to maintain uniform performance of the sprinklers throughout the system. To keep the pressures uniform at the irrigation zones when using undersize pipe, pressure regulating valves are used on each zone. The problem with this is that the irrigation system will require a pressure that is 15 PSI higher, due to the higher pressure loss of the regulating valves discussed above. If you are paying for the cost of pumping that extra 15 PSI you are going to be paying for a lot more electricity to run the system. So there is a trade off, cheaper installation costs vs. higher operating costs for the life of the system. A lot of people have gotten a rotten deal when buying a sprinkler system due to this trick. You can see how a unscrupulous bidder could create a low cost on the original installation at the expense of higher costs than are necessary for years to come. Another warning: if you use a mainline pipe that is too small, you will create water hammer, and it will destroy the irrigation system! If you follow the design tutorial it will keep you from making this mistake.