Where to Install a Pressure Regulating Valve on a Sprayer (Correct Setup Explained)

When building a sprayer, the pressure regulating valve needs to go in the right spot, or it won’t do its job. Fortunately, the correct placement is simple once you understand how they work.

Where the Regulating Valve Goes on a Sprayer

This is accurate most of the time; however, there is some important nuance to understand. Different sprayer types or regulating valves can affect how they should be installed. Read on for more details on where to install a regulating valve on a sprayer.

For more specifics on how these valves work, check out this full pressure regulating valve guide.

Diagram of Regulating Valve Location

The regulator belongs on the discharge side of the pump, because that is where the pressure is. On the inlet side of the pump, there is no need for pressure regulation.

A typical layout looks like this:

The pressure regulating valve should be installed on the discharge side of the pump, anywhere before the boom or nozzle outlets, where it can control pressure and return excess flow to the tank through the bypass line.

This video shows the basic installation of a regulating valve on an ATV sprayer:

Regulating Valve used in Video: TeeJet Poly Pressure Regulating Valve

If the regulator is installed incorrectly, it could limit its effectiveness or fail to work altogether. While there are different types of regulating valves, this is true for most of them. We will discuss the various types and how to install them, but it’s easy to understand when you know what a pressure regulator does.

What a Pressure Regulating Valve Actually Does

A pressure-regulating valve is one of those things that you don’t really think about when you think of a sprayer, but they have a vital role.

The primary job is to keep operating pressure steady by diverting extra flow back to the tank. But that is not the only function. A true pressure-regulating valve, not just a relief valve, will allow you to increase or decrease the pressure in the sprayer.

The ability to regulate pressure is important for quite a few reasons:

• Allows the operator to control the sprayer’s output
• Sprayer can change speed and maintain the same application rate
• Consistency means repeatable performance, no guessing
• Stops pump cycling (with 12-volt pumps)
• Protects plumbing components from excess pressure
• Can help agitate the tank mix (should not be primary agitation, more on this later)

Different Types of Regulating Valves & Where They Fit on a Sprayer

So far, we’ve discussed basic manual pressure-regulating valves, but several other valve types are used on sprayers, including pressure relief valves, throttling valves, and electronic regulating valves.

Pressure Relief Valves

As explained above, a manual pressure-regulating valve controls operating pressure by diverting excess pump output back to the tank through a bypass hose. These simple regulating valves are essentially adjustable pressure relief valves.

This is a common setup on ATV, UTV, and small boom sprayers for lawns:

Throttling Valves

In some cases, an operator may use a ball valve or gate valve to throttle flow to an accessory on a sprayer, thus regulating the flow to that feature. This could be used for managing the flow to an agitation jet or to rinse nozzles inside the tank.

Unlike a pressure regulating valve, the throttle valve does not open to relieve pressure; it is just opened more to allow increased flow, or closed tighter to decrease flow. Doing this may affect pressure, but it does not work to maintain a consistent pressure in the system.

Ball valves, gate valves, or butterfly valves can be used as a throttling valve.

In this example, you can see the position of the relief valve (manual regulating valve) and the throttling valve that is used to control flow to the agitation jet:

Electronic Regulating Valves

Another regulating valve type is the electronic regulating valve. This is common on larger ag and industrial sprayers, where automated or manual adjustments to the sprayer’s output need to be done from the tractor or sprayer cab while spraying.

Electronic regulating valves work with a rate controller and flow meter or pressure sensor to adjust discharge flow automatically, allowing the operator to maintain a consistent application rate regardless of changes in ground speed.

You can see in the example below that more complex sprayers use electronic regulating valves, pressure relief valves, and throttling valves all in one system.

Signs Your Regulator Is Installed Wrong

If you are building a sprayer yourself and find that you can’t dial in pressure, the regulating valve might not be bad. It could just be installed incorrectly.

Common warning signs include:

• pump turning on and off repeatedly, or surging (sprayers with 12V demand pumps, learn more here)
• pressure jumping around while spraying
• low or no pressure
• no flow

Wrong location might be the cause, but often the culprit is that the valve is installed backward. There is an inlet and a relief port on a pressure regulating valve. The inlet must be installed in a branch off the main fluid path.

The inlet is typically a port with male pipe thread, and the outlet is a female threaded port:

Step-by-Step Sprayer Regulating Valve Installation Example

Installing a regulator on a small sprayer is straightforward once you understand the layout.

Here is the process I typically follow:

1. Connect the suction hose from the tank to the pump inlet
2. Install a tee fitting on the pump outlet
3. Attach the pressure regulating valve to one branch of the tee
4. Run a bypass hose from the regulator back to the tank
5. Run the main spray hose from the tee to the boom or wand
6. Install a pressure gauge near the regulator if possible (many regulators have a port for a pressure gauge)

A pressure gauge is not required, but it makes adjusting your system much easier. If you are trying to dial in application rates, it is one of the most useful upgrades you can add.

Key Takeaways

There are different scenarios, but generally, a pressure regulating valve should always be installed on the pump outlet side using a tee fitting and a bypass return line to the tank. This setup stabilizes spray pressure, reduces pump cycling, improves nozzle performance, and helps keep your tank mixture uniform while spraying.

If you are setting up an ATV sprayer, lawn sprayer, or food plot rig, this is one of the most important plumbing details to get right early in the build.

For more details on pressure regulating valves, be sure to read this guide.