Sump Pump Check Valves Training Webinar: Sump Pump Check Valves

A Sump Pump Check Valve is a plumbing product that is specifically used in a Sump or Sewage Pump system. These valves help to make sure that the water that was pumped out does not come back into the pit. If you do not have a Check Valve installed, it will cause your system to work much harder and more often to pump out the same amount. Installing one of these valves will drastically reduce the stress that is put on your pump and save energy by limiting the amount that the pump needs to run. 

 When your pump is turning on too often and quickly, the motor will heat up and over time can burn out the pump. This can be very costly, especially if you are using a higher quality unit. A Check Valve is a fantastic way to protect your investment from unnecessary damage.

The video below is the 'Sump Pump Check Valves' training webinar and will focus on a general overview of what these products are, where they are used, and different styles available. 




Additional Notes

All sewage valves are required to handle a minimum of 2 inches for solid waste for non grinder pump sewage applications. A grinder pump will allow sewage lines and valves to be sized 1-1/4” or larger.


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Hello and welcome everybody to our webinar on Sump Pump Check Valves. We’re glad you decided to join us.

My name is Will Bender. I am the Quality Assurance Analyst here at Boshart Industries & backing me up, I have Paul Erb, who is the Research & Development Manager.

Feel free during the presentation to type out any questions that you have. We will do our best to answer all questions after the presentation. If you want to type out a question, you should see a side bar on the right-hand side of your screen. If you click on the top button, which looks like an arrow in a box, it will open up a little menu with a question box which you can type your questions and we will be able to see them. Please note the slide number if you’re referencing a specific slide. The numbers will be displayed on the bottom right of the slide.

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In the presentation, we’ll cover a little bit about the difference between sump and sewage valves, their applications, and when the two can overlap. I’ll go over some features of these valves and go over some Quality Assurance initiatives that we have here at Boshart Industries.

What are sump pump check valves?

First you need to understand what a check valve is. If you don’t know what a check valve is, a check valve allows a media to flow through the valve, but only in one direction. So, water can flow through the valve when the pump is running; but, when the pump shuts off, the water wants to flow back towards the pump. The valve prevents this by allowing the weight of the water to push down on the flapper and this causes it to close.

To fully understand these valves, we need to take a look at and understand the applications where they are used.


Sump pump systems remove water that comes into the sump pit through the weeping tile. 

The pump ejects the water from the sump pit, #1 on the picture, out through a discharge beyond the backfill zone, which is #2 on the picture. The backfill zone is typically a minimum of 10 feet from the foundation. The reasoning behind this is so that the water won’t seep back down to the weeping tile where you would end up pumping the same water over and over again. You can reference our installation tips on our BoshartU website to view more details.

Effluent, which is also referred to as gray water, collects in the septic tank as it separates from the solid waste, as shown by arrow #1.

In an effluent system, that gray water then flows and is stored in an Effluent tank, #2 shown on the picture, where a sewage ejector pump can discharge the waste from there to a weeping bed or to municipal piping so it can get treated elsewhere, as shown by arrow #3. The septic tank may not collect all solids, so the effluent pump, discharge piping, and check valve all need to be able to handle ¾” waste or larger.

Sewage systems can run by gravity, or if it is more practical, a sewage ejector pump will be needed to remove waste.

The sewage ejector pump, shown by arrow #1, will eject waste to a septic tank or a municipal sewer line, shown by arrow #2. Sewage check valves are often required for basements where sewage must be pumped up to a discharge line. All sewage valves are required to handle a minimum of 2 inches for solid waste.

Closer Look at Sump Pump Check Valves

Now we can look closer at the valves. Sump pump check valves should be installed close to the floor after the pump, as shown by arrow #1. This will reduce the amount of water that drains back to the pump after each cycle. The closer the check valve is to the pump, the less the pump will have to eject the same water that drains back down to the pit, which means the more efficient your system will be. And, the more efficient your system is means that the pump is cycling less.

So, the pump life is prolonged. When installing valves with flexible rubber couplings or compression gasket connections, thrust blocking is required to prevent lateral movement, or blow-off, in the pipe that could separate those types of connection. You can see the wooden thrust protection installed at the top of the piping by arrow #2. Not all plumbing codes are equal, so it is the responsibility of the installer to understand the local code before installing a system.

Boshart Industries offers two operating designs. A gravity type flapper and a spring assisted flapper design.

The first design operates by gravity. The pump can force water through, but gravity and the weight of the water will push back to close. The benefits of this design are that it is the more economical of the two and it takes very little force to open. This means that it can run on a battery powered back up pump in emergencies. Both this design and the next feature 15° Seats which reduce water hammer and flapper noise by reducing the time it takes the flapper to close.

The spring-loaded designs eliminate any ‘clunking’ noise that is common with sump check valves. The spring is constantly pushing down to the seat so there is more restriction on that flapper to open and close rapidly. Since these are quieter than the other design, it is best practice to inspect that the check valve is working every once in a while.

Different Designs of Sump Pump Check Valves

There are 2 body designs of flapper check valves as well as combination ball check valves, ball check valves, and back water valves. Each with their own array of connections and features. The first that I’m going to cover are the compact ABS check valves.

All of the compact ABS sump pump check valves use the gravity style design. They are constructed from 2 body pieces that are ultra sonic welded together. The flappers are made of one piece to ensure a positive seal on the seat. These should all be installed in a vertical position, so the flapper operation is not compromised.

These compact valves with threaded inlets may come with 3 outlets: Barbed for sump discharge kits, a slip solvent weld, or an attached flexible coupler. If the flexible coupling is used, the line will need to be thrust blocked because they are more apt to blow off. Also, the psi rating changes from 25 PSI to 4.3 PSI if using rubber flexible couplings so be cautious of that.

Weep Holes

Weep holes are a good idea that protect your pump and make the whole system run more efficiently.  A threaded check valve will be attached directly to the pump so there won’t be any discharge piping to drill a weeping hole into before the check valve. If the pump does not already include a weeping hole, then the solution is to have one in the valve. A weep hole will allow air to escape as the water is drawn into the pump.

If the sump basin runs dry, the pump can become air-locked which prevents water from entering the pump. This is when there is air in the pump and it tries to pull water up, but the air has taken up the space. It’s like holding your finger over a straw except that its air being trapped. As well as protecting from airlock, the weep hole will stop a vacuum from occurring under the check valve. This will allow the check valve to open freely so the pump will not have to work as hard to open the valve.

Weep holes are often already in the discharge casting of many pumps, but there are some that require a weep hole be drilled into the line before the check valve.

Check with the pump manufacturer if unsure.

The compact check valves with a solvent weld inlet do not come with any flexible coupling configurations and so thrust blocking is not required and the pressure rating is 25 PSI.

The compact check valves with flexible rubber coupling inlets all have flexible rubber coupling outlets. The maximum pressure rating is 4.3 PSI and need to be thrust blocked.

We have one compact ABS sump pump check valve that can be used in both sump and low-pressure sewage applications. Our BSC-200-SB model is our only 2” ABS check valve. It can handle larger sized sump pumps and meets the 2” size required for sewage applications as long as they are low pressure. A gasket pocket in the body design ensures perfect gasket alignment and a 100% blowout proof flapper gasket.

PVC Sump Pump Check Valves

All of the white PVC sump and sewage check valves are made from rigid white PVC and they can be used in both sump and sewage applications as long as they meet the criteria. For example, a 2” PVC check valve can be used in all applications whereas a 1-1/2” will only be good for sump and effluent systems. The maximum pressure is 150 PSI at 72°F. When pumping solid free liquids like in a sump application, it is best practice to install vertically.

When pumping solids and semi solids, the valves need to be installed horizontally, at most up to 45°, and oriented as per the markings on the valve, which will say something like, “Horizontal, use this side up”. The valve will not function properly if the hinge of the flapper is not positioned in the top center. The reason for this is because if you were to pump solids vertically, when the pump shuts off and the flapper closes, the weight of the solids still in the discharge pipe would settle on top of the flapper making it difficult or even unable to open. These valves are not just limited to dirty water applications. They can also be used in industrial, pool and spa, and pond systems.

The PVC compression check valves can connect onto ABS, PVC, Brass, and Steel piping eliminating precise cutting on existing lines. These valves are available from 1-1/4” up to 3”. The 1-1/2” and 2” valves have a spring assisted variant available for a quiet option.

The true union valves can also connect to the same piping as the compression valves. These are available in 1-1/2” and 2” sizes. Both sizes have spring assisted variants.

The solvent weld check valves connect to the same valves as the two previous. These valves are available in ½” up to 4”. The 1-1/2” and the 2” models have spring assisted variants.

Combination Swing Check Ball Valves 

Like the PVC check valves, the combination swing check ball valves offer the same features except that they are equipped with a ball valve and a union. Some wastewater pumping applications require a check valve, an in-line ball valve, and a union; so, this is a perfect solution. This allows easy service to the line by being able to turn off the flow directly after the check valve. And the union that holds the valve together makes it easy to service either side of the valve. Just like the PVC check valves, these can be installed vertically and horizontally as long as the correct orientation is used for each application, just as I had mentioned before.

Boshart Industries Combination Ball/Swing Check Valves have a unique feature on the handles. The top of the handles has a built-in spanner wrench for servicing the inside of the valve.

The compression combination valves come in 1-1/2” and 2” sizes. There is a spring assisted option for both.

The true union combination valves come in 1-1/2” and 2” sizes. There is a spring assisted option for both.

The single union combination valves come in 1-1/2” and 2” sizes. There is a spring assisted option for both.

Ball Check Valves

Ball check valves, which are not to be confused with combination ball/swing check valves, are typically used for sewage applications but is not limited to them. They feature a clean out port which allows access to the inside of the valve without removing it from the pipeline. The balls are self cleaning and won’t get caught on any debris that’s being pumped.

The backwater valves are another type of check valve that are designed for use in residential and commercial applications to prevent backflow in drainage systems. These valves are equipped with a gasketed flapper for a watertight seal and the whole valve is made from corrosion free materials so there will be no rusting, flaking, or pitting and the valve can stay smooth.

These are used in nominally horizontal drain lines. The step in the body helps keep flow moving towards the discharge and provides clogging protection. The access cap on the top makes it easy to clean out or repair the valve.

Here at Boshart Industries, we conduct plenty of tests to ensure that our sump check valves are up to our standards.

QA Department

On the product manufactured by Boshart Industries, we inspect a sample of each piece involved in the making of the valve by using our IM machine. This provides a quick dimensional inspection of each piece. We perform burst testing on a sample of the bodies of the valves to ensure that they surpass our pressure ratings. And we perform body joint tests by using our tensile tester to inspect the body connection strength.

The question is often raised, “what is the lifespan of these valves?”. It’s a difficult question to answer because every system will have some differences. Typically, our valves will last in an excess of 5 to 7 years, so we recommend replacing it that often. However, if the pump cycles frequently, that can result in the check valve wearing out faster than that. It’s good to remember that it is far less expensive to be proactive to an emergency than it is to be reactive to one.

If there is a dry season, the pump may not be on for a long time. So, it is best practice to cycle the pump by pouring water into the pit every once in a while. It’s a good idea to record the date that the check valve was installed somewhere nearby to the valve’s installation. Maybe a sticker. That way, it’s easier to know when a check valve replacement is due.

There are several precautions that can be taken so that in the unlikely event that there is an issue with the system, you can be proactive before any damage is done.

Liquid Level Alarms & Auto Dialers 

Liquid level alarms and auto dialers are a great way to get notified of an emergency if a water or wastewater system is not working properly. The liquid level alarms will create an audible alert if triggered. They also have the availability to add more sensors and alert beacons. The auto dialers can be linked with several numbers that it will notify if triggered.


That is the end of the presentation today. You can learn more about the features we offer at Boshart Industries as well as other useful information on plumbing and water well products.  At BoshartU, our goal is to equip you and your team with the knowledge you need to be more successful. We regularly publish new blogs and content that will help you become more comfortable and confident with our products. Thanks,

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