How To Install a Check Valve in Drain Pipe?

You mean sump pump discharge line, rather than in the sump pump suction line, to be more clear. It is unclear why the OP would put a check valve ahead of a 3 ft drop, assuming a vented sump, unless the OP has not been clear about which pipe is which.

The OP may be using an existing sump pump discharge line to carry out the washer drain, and wants to make sure the sump pump when pumping doesn’t back up into the washer. It may be that a lateral tap into the discharge line might create enough of a head loss to prevent back flow up to the washer.

Solar, you're right on about the advice. You don't want washer discharge water getting pushed into the sump pump discharge - that wouldn't be a good idea!

Also, if the sump pump flow rate is too high, it can pump faster than the drain can handle. Could it flow up the pipe high enough to flow past the washer drain line? Yes it can. Also, if the drain can get clogged or blocked (tree roots, etc) in the future, the sump could pump discharge water back up to the washing machine drain line and all over the floor.

I think there should be vent pipes running to the roof of the house (I've also heard that they sometimes vent out the side wall).

If it is a dishwasher there may be local codes about the check valve. Some places require it to be on the surface of the sink (above the dishwasher to prevent dirty water from siphoning back to the dishwasher). I solved the problem by attaching the drain hose to the underside of the cabinet. I don't know why a clothes washer would need a check valve.

GM, you beat me to it. Yes, the horizontal pipe must be on a slight angle down or you'll get standing water and also debris can settle there too.

Placing the check valve on a vertical section makes sense, so it doesn't get blocked. And you'd get even pressure on the seal - agreed!

And placing the check valve as close to the sump discharge line is key. You don't want the dirty sump water back filling, as GM posted!

GA to you!

In general, a check valve in the vertical can be more reliable than a swing check in the horizontal, especially for flows that may carry fibers. The closer you are to your check valve reversing pressure source, the better force to seal the valve.

With your piping, you may not need a check valve, especially if you can stand to throttle the sump pump flow a little. It seems unlikely you need 3 or 4 psi at the discharge into the sump, which is what you’d need to back up the flow to the washer.

Maybe you have a whole different definition of a sump pump than I do; I will give you a quick explanation on the mechanics of a sump and its function, at least the type we have in Ohio.

The washer, floor drains, basement sink, ect (grey water) run into a 15gal sump that is sunk into the floor of the basement. There is a sump pump that sits on a couple of bricks to resist the pump from picking up a stone or other heavy objects that may end up in the sump. From there, the pump has a check valve on the discharge side so that any water that is pumped out doesn't drain back in (from at least the discharge pipe, from at most other sewage).

There is a second sump pump on a house (depending on where you live) for the drain tile that surrounds the basement to keep water from filling it. This sump is usually set a few inches higher on the floor to keep any grey water from inadvertently ending up in this sump. It is always a good idea to have a backup pump in case of a pump failure or power outage. I recommend the venture style that operates off of city water, if one has city water. If one has well water, then a 12v system can be used, but they do not offer much more than 40 mins of run time.

Now if you know of some other type of system, please educate me. This is the type of "sump pump" systems we have in Ohio.

I suspect that the OP is planning to use the Sump Pump discharge line and piggy back his washer into it. A lack of clear language has the kind people Forum going in random directions as a result.

I got the same impression reading his post. I just re-read it and that's what I believe. Can the OP clarify this?

I grew up in Chicago and as I recall, sump pumps dumped the discharge water outside of the house, not down the drain. We didn't have septic systems, so we had a sewer line that ran to the main sewer at the street. On the outside of the house, water would flow down the lawn from the house to the curb (nearly all our homes were built slightly higher than the street) and then to the sewer system. Our house didn't have a sump pump, however there was one house in our cul-de-sac was built at the same level as the street, so they would always flood. They had a sump pump, but they had problems getting rid of the water as it would flood their yard and find it's way into the garage and basement. What they finally did is run a drain line to the street and into the curb. No more flooding problems.

My uncle and aunt had horrible problems with flooding. They had a regular basement and a deep basement. Their garage was below the second floor (split level house) and the driveway sloped down. Their garage always flooded, even with a sump pump. Their sub basement flooded so many times that the house was condemned and my aunt sold the house and the new owner started from scratch. I remember their sump pump discharged to the outside of their home. The house was up on a slope, so they dumped the sump water on the side of their home - opposite side of the garage. They had two sumps, one in the garage and one in the sub basement. The washer and dryer were in the sub basement with the water heater and utility room. Even with the two sumps, they still had flooding problems.

Back to the OP's problem. If the OP has a septic tank, then I guess it would be okay to dump the gray water from the washer, sink, etc into the sump tank, but it would still need to be pumped out to the septic tank, so he'd have a cost of running the pump even when there is no flooding. Instead, if he kept the gray water going to the drain pipe (not the sump basin) where it would drain into the septic tank, there wouldn't be a need to run the sump pump, saving electricity. When it rains and the sump tank starts to fill, he could pump the water either into the drain pipe or to the outside of the house - preferred way is to dump outside and not into the septic system. The rain water around the outside of the basement walls would drain back into the sump tank and get pumped outside the house. Again, hopefully there's a slope away from the house, so the water doesn't collect near the house.

If the OP has a sewer line, then it would be best to let the gray water just go out the home drain to the municipal sewer line vs let it flow into the sump tank and then pump it either to the outside of the house or to the drain to the sewer. When the sump tank starts to fill, the pump would turn on and drain to the outside of the house. However the OP wants to drain the water into the drain line. I see no problem doing this, as long as there's a check valve to keep the water in the drain line from backflowing into the sump pump. Also, I think there should be a check valve to keep the water in the drain from backflowing up the drain line. It shouldn't happen, but it could if the pump moves more water than the drain line can handle (it's possible if the drain line gets partially clogged - think tree roots).

I have never lived in Ohio, so I don't know what a typical sump system looks like. Plumbing code is very different in each state and sometimes even county or city wide. Allowing gray water to flow into a sump tank may be what the code requires. For instance, here in SoCal, we don't use PVC pipe for drains, we use ABS, iron or clay. When I was in Chicago this summer, I helped my mom fix a drain problem. The old cast iron pipe was clogged with rust and debris and I couldn't snake it clear, so I cut the old pipe out and replaced it with PVC. It was the only pipe available at Home Depot. I was told that Cook County requires it as their building code. Okay, that's the rule so I followed it.

So, regarding sump pumps, I don't know what Ohio code states. I can't even tell you what Illinois code is or Cook County for that matter. And since most homes here in SoCal don't have basements, I don't know the code here either.

Here's what I do know. A few years ago, I had quite a bit of flooding in my back yard. Being on a hillside, I was a bit concerned - I didn't want the hill to slide and all that standing water wasn't a good thing. My house is built on a slab, but water was getting under the slab because of the standing water. I looked into a few different types of pump systems. I have a septic tank with a leach tank (not a normal leach field). It's because our land doesn't perc well, so they used a leach tank when they built the house. I looked into putting a sump pump in the low area of my back yard with the plan of pumping the water to the drainage channel (concrete) that dumps to the street. It's a big drainage channel, so there's not much risk of overflowing. I looked into a submerged pump and actually bought one, but decided against it. I didn't want to put a sump tank in, so the pump would be sitting out in the open - not the nicest thing to have in my yard. My friend told me that the pump should be submerged to keep it from overheating. Next, I looked into a pedestal type pump and almost went that way. The only reason I didn't is that it looked ugly standing up in the middle of the yard and the drain pipe would be high up in the air too. I then looked into a sucker system and I bought one. I was getting ready to do it, but my friend told me not to do it, because the dirty water wouldn't be good for the pump. He said the gritty sand/dirt would kill the pump in no time. So, my project stalled and I haven't done anything yet. No hill slides even with the big rains we've had last year! I think I'll go the route of putting in a sump tank and using a submerged pump. I could hide the discharge line underground, then have it come up next to my drainage channel. It would look good and my flooding problem would be resolved.

Setlock,

What you wrote didn't set right with me, so I did some checking. In Ohio, generally a sump pump system is for discharging flood water from the basement of a home. It is not for pumping gray water from the washer, floor drain, basement sink, etc.

The system you describe has two sump pumps; one for removing gray water and the other for flood water. This doesn't follow what I've read about Ohio systems. Here's a link for you to read. https://ohiobasementauthority.com/basement-waterproofing/products/sump-pump/

The water from drain tile is suppose to flow into the sump tank. The sump tank may have one, two or even three pumps. The first two run on the home electrical system, while the third runs on a battery back up system. Gray water isn't suppose to be dumped into the sump tank. Instead, it should be run into the normal drain line or it can be used outdoors for landscaping irrigation if code allows. Why dump it in the sump tank? You have to use electricity to run the pump to get it out of the sump tank. The second sump pump isn't set up higher to keep gray water from being pumped. Take a look at the three pump system in the link above and it describes the use of the three pumps. The first pump is used as the primary. The second is used as a back up if the first pump fails or if it can't keep up with the water inflow. The third is a battery back up.

Also, the battery powered back up system sold by the company in the link above will pump 11,500 gallon on a full charge. That's not 40 minutes of run time as the pump can't 17,250 gallons per hour.

It follows what I've always though a sump pump system is suppose to accomplish. Ohio codes aren't radically different from Illinois or CA.

sorry you have an incorrect website.

your source is a waterproofing company that offers a type of waterproofing where a homeowner is looking for an alternative choice than dig up around the basement and replace defective tile.

please do some more homework. and you will understand how your explanation is flawed. I will answer one of your questions tho' "why dump grey water into a sump", the answer to this would be when you have a washing machine and or a utility sink in the basement, that water dumps into a sump and then gets pumped out into a septic system (no sewer lines where I live). there is only one sump pump per sump (besided, like I said a back up such as water or battery powered if a home owner decides to install one, it is by no means mandatory).

if a property does not have enough fall (lowest toilet, to septic system, to leach bed) sometimes a solids pump is installed which will chop up the crap and pump that into the septic system. its usually a good idea to shy away from this type of system cuz those pumps seem to fail in a couple years.

ok, enough on sumps and pumps.. I will guess you have zero experience with sumps..

Setlock. Did you look at the website I provided? If so, how did you come to your conclusion that they are an alternative choice for a defective tile? I looked at the site again and the didn't discuss that as the problem they have a solution for.

Your solution of dumping grey water into the sump may have a specific application. For homes that require the grey water to be pumped to the septic tank.

For most applications, where the septic tank is lower elevation than the grey water drain line, then gravity will push the grey water to the septic tank, correct. So, why dump it in the sump and use electricity to pump the grey water to the septic tank? You're not going to convince me that it's energy efficient to do things that way, nor will you convince me that it's per code. The site I provided in my previous post is from a company who is licensed in your state and I don't think they're performing work that's out of code.

I think we can agree that not every home has a sump pump. So, if a home doesn't have one, but the owner is experiencing flooding, so they decide to install a sump pump, you're not going to say that they need to dump their grey water into the sump pit, then pump it out are you? I hope not, because that makes no sense, unless the grey water is causing the flooding, which is highly unlikely.

And just in case you're asking, the example above did happen to a house on our block when I lived in Chicago. In fact, it happened to two homes and neither one pumped their grey water into the curb, however they did pump their flood water to the curb. And please don't say that they did it wrong, because both had licensed contractors do the work and I don't think they make a practice of doing work out of code.

I'm not going to insult you and say you have zero experience with sumps, but I feel that your experience is in a very limited field; septic systems that require a pump to get the water from the home drain to the septic tank.

Setlock,

If what you wrote is true, then you home is in violation of plumbing code. Read this!!! Then hire a contractor, so you can get your house back into code.

http://morocco-crescent.com/2015/06/26/why-washing-machines-should-not-drain-into-sump-pits/

My gut feeling is that your home is not out of code and you simply don't understand how a sump works, but it's either that or your home is not in code.

everything is legal. two sumps. one is grey water the other is drain tile. not sure what you don't get with that setup.

this is how homes with septic systems are designed.

"this is how homes with septic systems are designed."

Wow, that's a bold statement and it's not true.

My house has a septic system and it was not designed with two sump pumps, nor does it have a grey water sump. In fact, I don't think one home in our area has a grey water sump. It would be a rare system here in Southern California.

do you have a basement? do you have a slop sink in the basement? if you answered no to either of these than what I said would not make sense to you.

The house I grew up in does have a basement, though it's a split level, so the basement is 5 steps down from the first floor - the first floor is one big step above ground level. And the house sits slightly up from the street or back yard- gravity pushes the water away from the house.

In the basement, we have a drain in the utility room floor. We have a washing machine, utility sink, shower, toilet and sink too.

Most of the houses in our tract did not need a sump, because we have a sewer system and the homes are above street level. We never had rain water which flooded more than 1/3 of our front lawn and it never reached the house. The only time the basement flooded was due to the sewer system backing up (it backed up from the main 4 lane road). Not a good thing for everyone in the neighborhood.

One house in our cul-de-sac had a poorly designed sump pump system. It would pump the water out of the basement sump and right outside the house. The house was built at street level, so with a heavy rain, water wouldn't exit the property at the curb and would flood the back yard which was slightly lower than the house. If the rain was heavy enough, the flood water would reach the house and fill the sump via the tile. With the pump dumping the water right outside the house and more rain water falling, the pump would be overwhelmed and the sump system wouldn't be effective. After many, many, many basement floods, the owner put a hose under the lawn and to the curb, so the sump would dump the water off the property. No more flooding!

My best friend's next door neighbor also had a house which was built at street level. They had flooding problems too and their sump pump dumped the water next to the house - again, not a good design. The owner was not very handy to say the least. My friend and I watched him attach one of those flat hoses to the pump outlet just outside the house. He ran the hose across the driveway - one of those flat ovalish hoses that expands when water flowed. The next big rain, my friend and I watched as water was pumped to the other side of the driveway through the hose. The water found it's way back to the house and of course back to the sump pit, where it was overwhelmed and the basement flooded. I told the owner that my neighbor ran the hose under his lawn and to the curb. He hired someone to finally do the job right.

My point being that yes, I do know about basements flooding. Most of our homes were laid out properly, so water would flow from the house to the street. The few that didn't had a sump pit/pump system. They did not pump flood water through the sewer pipe, but instead dumped it right outside the house or to the curb. The toilet, shower, sink, utility sink and washing machine would drain through the normal house drain, which would flow to the sewer system.

You can't say that it wasn't done properly. All you can say is that it's different from your system. Not right or wrong, but different.

What I do have a problem with is why not dump the water from the sump pit (not greywater) out to your yard. Since you have a lake and I'm assuming that your house is built above the lake, then flood water would flow to the lake. Then your greywater system would be separate and your leach field/pit wouldn't be overwhelmed by too much water - during those times when you have a lot of rain and the water needs to be pumped to your septic system?

Here in CA, one of our rental houses has a septic tank. It has a leach pit, not a field - I was told they were having problems getting the land to perq, so they had to use a leach pit. The house is built on a hillside and the layers of ground were disturbed so the water wouldn't flow down properly, hence the need for a leach pit. Anyway, we have had a situation where we overwhelmed the leach pit and our septic tank backed up. The drain from the house to the tank backed up and the inspection cover (for the drain line) actually was pushed up by the water in the line. We had the tank pumped - we thought it was the cause, but it wasn't. At the time, I didn't know we had a leach pit. One of my friends told me that it's probably a plugged up leach field (lines in the leach field are clogged or damaged). Then my neighbor told me that she remembers that they had problems getting the ground to perq, so they used a leach pit. Bingo - I checked county records and found the leach pit. We had used too much water and overwhelmed the pit. At the time, we had 8 people living in the house (4 bedroom home) and the girls were taking very, very, very long showers. We have a tankless water heater, so they just stayed in the shower a long time. New rule - 15 min showers max! That fixed the problem.

sorry that I am not explaining properly or you do not have enough background on the subject. lots of time, trying to be a google expert can get you down the wrong path.

a footer drain tile resides around the base of the basement, usually on the outside of the wall, but can be cut into the floor on the inside of the block wall. This sump prevents a flooded basement (not to drain a flooded basement as you suggested) and maintains water from a high water table or heavy rain.

and yes there is usually a second sump that is set up for a washer and slop sink that resides below the discharge of the septic pipe (such as in the basement).

you would never use grey water to water your landscape, that makes zero sense. you would take the water from a washing machine and water your garden with this? I don't think so, this would be run thru a septic system and the effluent is then exited thru a leach bed, or some other type of system.

out in the country, we do not have sewer lines. we have our own septic systems and therefore we drain all grey water into the septic system. the reason we have a sump in the basement is because in flat terrain, we need to pump the water to the septic system which is at a higher elevation than the washing machine, or slop sink (if resides in the basement).

now you can possibly water your landscape with your drain tile discharge, but I have never heard of anyone doing this. I, actually have my drain tile discharge dumping into my downspout drain which subsequently goes into my lake.

so nothing illegal, all perfectly normal. maybe you need to google some more.

I don't think you explained it properly. The OP did not mention that he does or doesn't have a septic tank. Nor did he say whether his drain line is above or below the sewer or his septic tank. So, it shouldn't be assumed that he lives in the country and has a set up like yours. Nor should you assume that everyone here (or me) would know this. Maybe I'm wrong, but I believe that the majority of people in the US live in urban areas, so they don't have septic tanks and their drain lines feed the sewer system via gravity. You system may be the norm for the area where you live, but it's not for the majority of people in the US.

"you would never use grey water to water your landscape" Again, I'm curious why you would make this statement without considering the most populated state in our country. I'm pretty sure you heard about the droughts we had - yes, some are very severe - our local lake dropped by 140 feet in 2015! So yes, we use gray water from our washing machine for our gardens and lawns. It's not only limited to California as much of the western US is having water issues - look at Lake Mead near Vegas - it still hasn't recovered and it may not for quite some time.

It may also surprise you that one of the most affluent counties in the US uses recycled water for tap water. Now it's your turn, Google Orange County recycled water.

In LA County, if you want to build even a small housing development, you can't get a permit without proving you have enough water to support the project. For many developers, this means you need to buy water rights from Kern County or elsewhere. You can Google that one too.

The main purpose of a sump is to reduce the chance of flooding. I think we can both agree to that.

The sump pump just sits there, waiting for the pit to fill to a certain level. Until it does, the pump isn't operating.

When the sump pit fills with water (the water from the outside of the house no longer drains fast enough), the float or some sort of sensor which turns the pump on and it TYPICALLY dumps the water away from the exterior of the house. I guess you could dump it in your septic tank, but why?

I think this is what the OP wants to do, to drain the grey water into his sump pit.

How high is the sump pump lifting the water from the sump? Higher than the discharge of the washer?

If so, the check valve should be located at the pump on the discharge side.

The pump should also be self cleaning and rated for the intended service.

The discharge water will have lint fibers in it, and will clog the pump frequently if it is not of the proper design.

A vortex type impeller pump is recommended for extended service life.

A vacuum breaker is required on all new installations, and is normally installed in a TEE fitting with the top of the Tee facing up; the vacuum breaker valve is located there. It is not necessary to vent to the outside.

Consult a local code authority for specific regulations in your area.

Good luck.

As far as I understand it,based on limited information,you are not concerned with a leaky basement,but you have a washing machine on a below-grade-level location.

How high does the water have to be lifted from the washing machine outlet?

As I understand it here,the water actually drops about 1 foot from the machine level to the sump.

You may be able to pump directly into your sewage system.

You will need a P Trap near the wall to block sewer gasses when the water is not flowing.

The washing machine pumps are quite powerful and can push water a long distance.

You may not need a sump,but you will need a check valve as close to the washing machine as possible.

Please give more details and a sketch of the system you propose to use.

The way I read the question (and I could be wrong there isn't much information given), is that the OP has an existing washing machine drain line. He is installing a sump pump and would like to discharge it to the washer drain line rather than make an additional wall penetration. If that is the case, I would think there should be a check valve in the sump discharge line to keep wash water form running into the sump.

If there is a concern of the pump pushing water back up to the washing machine, an additional check valve could be added in the vertical portion of the drain line between the washer and pump discharge, but normally the drain line would be sized large enough so that wouldn't be a concern.

Hi Troy,

That's what I came up with, but there's some confusion here on the site about what the OP wants and what a sump pump is.

I also think the drain line would be sufficient to handle the output of the sump pump, however with age, drain lines can become partially clogged. Normal TP, hair, grease, etc can close off part of the flow. The big problem I see is tree roots or a large rust blockage from a cast iron pipe. This summer, I fixed a cast iron drain pipe (vertical section) that was completely clogged from a rust bridge. I didn't think it was possible on a vertical surface, but it did happen. So a check valve upline of the sump discharge point would be a good idea - to block the water from running up to the washing machine. It's cheap insurance, just in case.

It would be rare to put a <...CHECK VALVE...> in a drain line, as the idea of a drain line is that gravity does all the work. It begs the question "why?".

Please stop SHOUTING. Readers here are trying to get some sleep.

Think of it like a flapper valve in the pipe. If water starts to back up from the down flow side up, the flapper valve keeps it from flowing past a certain point.

Years ago, the house I grew up in had a flooded basement (it flooded two times since my parents bought the house in 1971). Water from the sewer system flowed back through the drain line and into the basement. I believe the house was build in 1962, so there must not have been a requirement for a check valve. If there was one, we wouldn't have had a flood. The sewer system was pretty good in our subdivision. So what happened? The main sewer line on the four lane state road was blocked and backflowed into our subdivision. All the houses flooded! I remember seeing rolls of carpeting on the curb after the flood. The rain wasn't even that bad. I remember it was a short burst - maybe 30 minutes or so. It rained hard, but not for long. The street was wet, but clear, then out of nowhere, the street started to flood, then our homes!

another reason to put a check valve in a drain line is if the sump pump crock is below the level of the drain line. Then the sump has to pump the water up to the drain line so that it can then use gravity to flow away. it stops water (that took up the volume of the pipe) from flowing back into the sump. could be a gallon, could be more depending on the length of pipe.