Drip irrigation is an efficient way of watering a lawn, garden, greenhouse or agricultural land. It does this by allowing water to drip slowly and steadily to the roots of plants, either on or below the soil’s surface. A watering system like this is great for reducing water waste and making sure all your plants get exactly as much water as they need.
Although drip irrigation is often used in large scale agricultural areas, you can also set up this system at your own property. There are several parts to a drip system that are very important, and one typically included in any drip irrigation set-up is a pressure regulator.
A pressure regulator is a device that reduces the water pressure and maintains the consistent flow of low-pressure water for drip systems.
Pressure regulators are not essential, but tend to make a much better drip system. Drip irrigation usually requires lower water pressure than the normal pressure found in the average home water supply. The low water pressure makes sure that the drip system works effectively without wasting water.
In this article, we will go over the importance of pressure regulators to help boost the performance of drip irrigation systems. It features a detailed discussion on pressure regulators and the important role they play in a drip irrigation system.
Table of Contents
What Is A Pressure Regulator For Irrigation?
The main function of a pressure regulator is to boost the overall performance of a drip system. First, this device reduces the inlet water pressure coming in from the main water supply. Then, it creates a constant low water pressure through the system. It maintains this low pressure even when the main water pressure fluctuates.
You might also come across the phrase “pressure reducing valves” or PRV. They’re also pressure regulators; they’re just two different names for the same piece of equipment. However, specific models may vary, depending on the manufacturer.
Pressure regulators are generally installed on the outflow side of the valves. It should be placed after the backflow preventer and filter.
How Does An Irrigation Pressure Regulator Work?
Even though it is a relatively small device, a pressure regulator has several components. The main ones include the inlet, fixed seat, throttling stem (t-stem), diaphragm, spring, and outlet.
The water flows through the regulator’s inlet and around the fixed seat. It then goes through the t-stem, which is a hollow cylinder attached to a large diaphragm. This diaphragm is located at the outlet end of the regulator. The spring surrounds the t-stem.
When high-pressure water passes through, the diaphragm is activated, causing the spring to compress. This compression pushes the t-stem toward the seat. The opening near the seat closes just enough to achieve just the right amount of pressure and flow.
What Pressure Is Needed For Drip Irrigation?
Unlike sprinklers, most drip irrigation systems need water pressure between 10 to 30 psi (pounds per square inch) because the components are designed to operate under low pressure. If the water pressure is higher than 30 PSI, it can damage the system.
For example, if water pressure is too high for a drop irrigation system, fittings get disengaged, and emitters become distorted.
A pressure regulator prevents the drip system from wear and tear and can save you from having to replace them, which can be a massive headache!
When choosing a pressure regulator, be aware of its optimal operating pressure range. Regulators that offer 25 psi work best in most drip systems. However, if you’re using a thin-walled drip tape, you need a regulator with a maximum of 15 psi to make sure that your drip tape lasts as long as possible.
What Is The Difference Between A Flow Regulator And A Pressure Regulator?
The main difference between a flow regulator and pressure regulators lies in what they do in your irrigation system.
A flow regulator’s job is to control the amount of water flowing past through it. If there’s an excess in the amount of water coming through the system, the flow regulator closes its valve to reduce the water flow. Flow regulators are usually used in sprinkler systems.
A pressure control valve, on the other hand, maintains water pressure. When water flows up, and through the regulator, the valve compresses to create lower pressure as the water flows out.
Flow regulators and pressure regulators usually have similar parts like diaphragms, throttling stems, springs, inlets, and outlets. However, the difference between water pressure vs flow rate means these two components have different goals and aren’t interchangeable.
Do I Need A Pressure Regulator For Drip Irrigation?
It is highly recommended to install a pressure regulator in your drip irrigation system. One of the benefits of having a regulator is consistency in water distribution. With even distribution, it becomes much harder to over, or under, water your plants.
A pressure regulator also extends the lifespan of your drip system. This is because certain system components like tubes and tapes can only handle pressure up to a certain point for so long. Most drip line systems often come with weak walled piping. This is intentionally by the manufacturers to make installing couplings and components easier.
You may have heard or read about some people choosing not to use pressure regulators. The usual reasons for such a decision include costs, elevation, and system design. They are usually pretty confident that their water pressure is good enough based on their system’s setup.
However, consistent pressure from a water source is hard to achieve. You need to constantly monitor the drip water pressure yourself if you don’t have a regulator installed. If you don’t have a regulator, you’ll also need to know how to measure water pressure.
You can also test your main water supply pressure before purchasing a pressure regulator. You’ll need a pressure gauge available in most hardware or home supply shops to do the test.
Start by installing the gauge to a hose bib or tap. Then turn on the water to get a pressure reading. A reading of 30 to 40 psi is considered safe for you to attach your drip irrigation system directly to the water source. Do take into consideration that home water pressure will fluctuate. A pressure of 80 psi or more will stress the pipes and fixtures of most drip systems and can cause damage to your system.
Which Pressure Regulator Is Best For Drip Irrigation?
There are two types of pressure regulators: non-adjustable and adjustable. Both types can be used for a drip irrigation system. A non-adjustable regulator usually recommended for smaller spaces or simple home drip systems with fewer than three control valves.
Non-adjustable regulators have pre-set outlet pressure and flow rate ranges decided by the manufacturer. If the flow rate doesn’t meet the product’s range, the regulator won’t work. On the other hand, an adjustable regulator comes with a knob or valve that lets you adjust the water pressure as you like.
Non-adjustable pressure regulators are budget-friendly and are usually made of plastic. They should be installed after the control valve. Installing them the other way around often creates a high-pressure change that can damage the entire drip irrigation system. If you have multiple control valves, you will need a regulator for each one.
The adjustable regulator is typically more expensive, but it’s more flexible and accurate, making them perfect for larger agricultural spaces. The adjustable type of regulator is often considered the best option for many reasons compared to its non-adjustable counterpart.
There are also other factors to consider when choosing a pressure regulator. As mentioned, non-adjustable pressure regulators have a preset control pressure. For most regulators to work correctly, the pressure coming from the water supply has to be 5 PSI above the regulator preset pressure. For example, a regulator with a preset 30 PSI can be used on a water source that has at least 35 PSI.
Some manufacturers offer pressure regulators for a variety of pipe thread and hose thread sizes. If you have a specific manufacturer in mind, check with them or your local irrigation professional which of their regulator models fits your pipe thread type and size.
Related Questions:
Why Is My Pressure Regulator Leaking?
The best way to troubleshoot a pressure regulator leak is to look at where it’s coming from. If it’s a minor leak from the small hole at the side, it’s pretty normal – the relief valve is working as it should be. However, if water is leaking continuously from the relief valve or leaking from a crack, your pressure regulator might be faulty or damaged.
If the leak is coming from the threaded connection, you might just need to tighten the connection. Leaking can also occur if you install the pressure regulator in the wrong place. The correct assembly positions should be timer first, followed by the backflow preventer, then the filter, then the pressure regulator.
Will A Pressure Regulator Reduce Flow?
Pressure and flow rate have a cause-and-effect relationship. Generally, you would think that high water pressure increases the flow rate. Pressure regulators are designed to reduce the pressure of the water coming in. It does so by narrowing its diaphragm to reduce the flow of water. That’s how your pressure regulator reduces the standard flow rate of a water source.
But pressure regulation reducing the flow of water isn’t a problem for your drip irrigation system. What’s important is that your drip system has a way to properly manage pressure to continue working at the highest level possible for a longer period.
Disclaimer:
This article is published for general informational purposes only and does not constitute professional advice. Any action you take upon the information you find on this website is strictly at your own risk. Always ensure you have the right qualifications and certifications to carry out DIY work and never put your safety at risk. Hills Irrigation recommends consulting a professional for all electrical and plumbing work.
Vince is Managing Director of Hills Irrigation and is supported by Lisa in an administrative capacity. Andrew, Isaac and Megan look after the day to day needs of both online and shop customers. As Project Manager, Vince is also responsible for installation projects along with his team. It is his responsibility to work closely with clients to ensure that scope of work is understood and followed.
