Does a Check Valve Go Before or After the Pump?

Does a Check Valve Go Before or After the Pump?

A check valve is a vital part of any pump system. One of the biggest questions I hear regarding proper check valve installation is whether it goes before or after the pump, since the placement of the check valve will have a major effect on how well it works in your system.

A check valve should always go after the pump to that the flow can be controlled without stopping the pump. This is the most common check valve placement in a pump system. Placing the check valve after the pump also prevents backflow and keeps the pump from becoming damaged. The most efficient pump systems place the check valve after the pump but before the outlet control valve.

This guide will focus on all of the details you need to know to ensure that your check valve is installed in the most efficient way possible. There will also be a frequently asked questions section at the end to answer any lingering questions that you may have.

Where To Install A Check Valve On A Water Pump?

A check valve should be installed after the water pump in most situations. Installing the check valve after the water pump will prevent backflow and allow for easy stopping and starting of the water flow. This installation method is essential if you are using a female control pump system to effectively prevent backflow.

In order to allow easy access to the check valve in case repairs are needed, it should be installed after the pump but before the outlet control valve. That being said, there is another less common option that you can consider that may be better for your situation.

Some water pump systems may benefit from installing the check valve before the water pump. This installation method will allow the water pump to fill without actually pumping any water. It will not prevent backflow as efficiently but will cut down on the amount of work your pump needs to do.


Detailed below are some of the most frequently asked questions regarding check valve installation. If you have a lingering question that you would like answered, this section can be helpful.

Can You Put Two Check Valves On A Sump Pump?

It is not advised that you use two check valves on a sump pump. A sump pump is designed to work most efficiently using only one check valve. Using more than one check valve will result in friction loss which can affect the pressure and efficiency of your sump pump.

Using more than one check valve with a sump pump will also increase the chances of a stuck-open fault, which is a common cause of backflow that can damage the pump. Two check valves will also increase the frequency of air pockets which will also affect the efficiency of your pump system.

Because of this, you should only utilize one check valve with your sump pump to cut down on the workload of your pump and decrease the chances of serious issues. Sump pumps are designed to work efficiently with only one check valve and do not generally require more than one.

Do All Submersible Well Pumps Have Check Valves?

It is advised that all submersible well pumps utilize a check valve. In most cases, any submersible well pump you have installed will already have a check valve included. That being said, it is important that you make sure and install one if there is not.

For maximum efficiency and protection for your submersible well pump, a second check valve can be installed on the discharge line. This second check valve should be installed within 25 feet of the pump below the water supply line.

In most submersible well pump installations, a check valve is installed at least every 200 feet to help with weight distribution. If you do not use a check valve with a submersible well pump, then the chances of serious issues are greatly increased.

These issues include backspin, water hammer, and upthrust. All of these issues can damage the pump and render it inoperable, leading to costly repairs.

Does The Check Valve Go Before Or After The Ball Valve?

The check valve should be installed before the ball valve to help prevent backflow in your system. That being said, most people use one or the other in their pump setups. Since a ball valve and a check valve serve many of the same functions, you will need to decide exactly what you need for your setup.

If you believe that you need both a check valve and a ball valve in your setup, there are dual valves that you can purchase that are two-in-one. You may not need a ball valve and a check valve together but if you do, you should consider one of these two-in-one valves.

Is A Check Valve Necessary On A Sump Pump?

It is always necessary to install a check valve on a sump pump. Not utilizing a check valve in a sump pump system will eventually cause backflow issues that can damage your sump pump. Even if the water left in the discharge pipe does not damage the sump pump immediately, it will still cause issues.

These issues include rising water levels in the sump pit, causing the pump to run more than necessary. This will increase the energy costs associated with the sump pump, which is never a good thing. Using a check valve in a sump pump system will increase the overall efficiency of the pump.

It will also protect the pump from the issues mentioned above and prolong the lifespan of your pump by several years.

Do You Need A Check Valve On A Shallow Well Pump?

You will need a check valve installed on your shallow well pump. Like any check valve, it will help to prevent backflow and other issues that could potentially damage the pump. The check valve on a shallow well pump should be installed in the suction piping as close to the water source as possible.

You should avoid installing the check valve too close to the pump’s inlet or near the discharging area of the pump. This will allow the water to only flow upward and not backflow down into the well. Because of this, the check valve is always installed at the bottom of the well.

Some setups do use a check valve installed above ground but require additional fittings to work properly. This setup may be more suited for your system, as it will be difficult to reach to check the valve once it has been installed if it needs repairing or replacing.

If you are wondering how to power a well pump with a generator, check out this article.

Final Thoughts

We hope this guide has provided you with everything you need to know about check valve placement in your water pump system. You now have all of the information that you need to properly install your check valve so it works efficiently.

Just to reiterate, the check valve should always be installed after the pump. This way, the chances of backflow and damage to the pump is minimized. If you are unsure of the placement of a check valve in your pump system, you should consult a professional for more information.

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