Sewer Check Valve: Installation Guide for Locking Device

Nikolay Fedorenko
Checked by a specialist: Nikolay Fedorenko
Author: Antonina Turyeva
Last update: September 2019

Unscheduled repairs are unlikely to please anyone. Especially when an apartment or a country house was flooded with waste water from a sewer pipe. A local valve can prevent a local catastrophe. It is enough to choose the right model and install it.

We will tell you how the device works, why it will become the best defender against the reverse flow of effluents for the next 5 years or more. We have described in detail the types of valves, their design features and operating rules. Based on our recommendations, you can choose the perfect device that solves your problems.

Structure and purpose of shut-off valves

To protect your home from a sewer flood and not to cover the holes in the sink, bathtub and toilet with towels, bathrobes, bedspreads and everything that comes to hand all night, put special locking devices. Sometimes even one plastic bag accidentally flushed into the toilet can cause disastrous consequences.

What is a check valve?

To protect against the flow of effluents in the opposite direction, special devices are used that operate at the right time and block the path of waste water. This is a check valve used for sewers in private homes, apartments, office premises, manufacturing. Also, locking devices are installed in heating and water supply systems.

Check valves are able to close the hole in the sewer pipe at the right time. And all the drains that started their movement in the opposite direction will be forced to look for another way.

This situation can occur in a multi-storey apartment building, where there is usually a common riser for residents whose apartments are under each other. Then the sewer eruption can be seen even on the 2nd floor, if the tenants of the 1st took care of installing a shut-off sewer valve.

If the valve is also on the 2nd floor, then it is unlikely that it will reach the 3rd pillar of sewage drains - under the pressure exerted by it, a blockage is sold and everything will float where it should - into the communal sewer pipe.

Device and features

Shut-off valves for sewage can be of very different shapes and sizes. They are made of various materials and have different working parts. But they all act in the same way - they block the path of drains, which sharply changed the direction of their movement.

Check valve for several appliances
Several sewer branches can be connected to the check valve. Regardless of the model of the locking device, you need to choose the installation location that is most convenient for checking and cleaning in the future

In general, a valve consists of such parts:

  • inlet and outlet nozzles;
  • lever for forced withdrawal of drains;
  • a membrane / working body for overlapping the entire section of the pipeline
  • cover for inspection and cleaning.

The working mechanism depends on the model - it can be a rubber ball, a damper or other device that completely blocks the pipe.

Check valve operating mechanism
If the drains go in the right direction, then nothing prevents their movement. Once they change direction, the working mechanism will close the entire cross section of the pipe

Is it needed in principle?

Locking devices are not required for installation in all situations. In some cases, these devices can be dispensed with.

For example, a family living in an apartment on the 5th floor may not worry about flooding the bathroom with sewage through a clogged riser.

The red arrow indicates the direction of drains
When installing a check valve, you need to monitor the direction of the red arrow - it indicates the correct direction of the drains

A non-return valve is needed if:

  • the apartment is on the 1st or 2nd floor of a high-rise building;
  • in a private one-story house / cottage;
  • in a 2 or 3 floor cottage;
  • in office premises on floors 1-2, especially if the building has old pipes.

It is for such categories of premises that it will be cheaper to install a locking device than to deal with the consequences later.

Forced ceiling lever
The valve on top has a lever for forcing the sewer pipe

Varieties of check valves

All shut-off sewer devices can be divided at the installation site:

  • for the street;
  • for the room.

If the device is to be mounted in a street sewer, then you should choose a frost-resistant model with a large throughput.

Steel Check Valve
For installation in the room, simpler options are suitable. Moreover, it can be both plastic models and steel ones.

Depending on the installation method, they emit:

  • flanged;
  • interflange;
  • coupling.

The second option requires the use of welding and is used in metal pipelines. But this is a quick and easy way, not requiring much time to install.

The flange method puts a check valve on pipes of large diameter. Most often on the street. And with the clutch method it is more convenient to install devices of small diameter. Basically, this option is used indoors. The main thing is to choose a place during installation where you can safely remove the cover and clean the valve, it is clogged.

Also, according to the type of locking device, a rotary, lift and ball valve are isolated. This is the difference in the method of fastening the locking mechanism in the device itself. In the rotary valve, a damper is used; in the spherical working body, a ball protects the cross-section of the pipeline.

Ball as a locking element of the valve
The model of the check valve for sewage, in which the ball is used as a working body, is most often used in industrial premises

In the lifting model of the shut-off valve, there is a special lock - a spool, moving under the influence of a spring or under its own weight.

Homemade Check Valve
Sometimes home craftsmen offer their own version of a homemade device - this is not always justified. Such a device may not withstand the pressure, and subsequent repairs will fly into a pretty penny

Nuances of choosing a check valve

Before buying a locking device for personal use, you should carefully analyze the features of your sewage systems. Based on its specifics and to choose.

When choosing the best option, you should pay attention to such characteristics:

  • bell diameter;
  • material;
  • size of fixture;
  • installation complexity;
  • quality and guarantee;
  • price.

Moreover, the price is clearly in last place - the reliability and functionality of the valve do not depend on it. Here you should focus on your financial capabilities. For example, it makes no sense to buy a fancy model of a locking device with an electric motor for more than 120 thousand for a modest cottage with cheap sewer pipes made of plastic.

Horizontal Sewer Check Valve
For the arrangement of sewer systems, models of check valves with horizontal and vertical installation methods are produced. Horizontal mount on trunk lines, vertical on risers

The most important parameter is the diameter of the sockets. It is he who is the key characteristic and must match the diameter sewer pipeinto which the check valve is to be mounted.

To take a smaller or larger cross-sectional size of the device and buy special adapters will be the wrong decision. This will disrupt the smooth functioning of the system and may disrupt the throughput of installed pipes.

The material from which the check valves are made is the same as the material of the sewer pipes:

  • plastic;
  • steel, including stainless steel;
  • cast iron;
  • bronze;
  • other materials less commonly encountered.

Of the options encountered, it is best to choose the same as the installed sewer pipes in the house, cottage, apartment. It is impractical to insert a plastic valve into a cast-iron pipe and vice versa. Moreover, plastic models are the most affordable.

Valves made of metal
Models of locking devices made of metal should be installed correctly in the same pipeline made of the same material.

As for the size, the locking device should be selected based on the availability of space for its installation. Do not forget that there are valves for vertical and horizontal installation.

Most often, the second option is chosen. But in the absence of sufficient free space in the bathroom, in the kitchen, behind the toilet or in the utility room, they take the vertical version.

Wafer Type Check Valves
If there is very little space, then a wise decision is to use interflange models of check valves, for the installation of which only seals are required

The ease of installation depends on the cost of installation work, if you are planning an invitation to a plumber. If this is a simple plastic model, then it will be possible to put it under the power of a home master who has a minimal set of tools.

Also, before buying, it will not be superfluous to look at the model you like and check it so that nothing hangs and creaks under your fingers. It is necessary to pay attention that the arrow drawn by the manufacturer is on top.

On each high-quality product, the direction of movement of sewage drains must be indicated, which eliminates installation errors.

The seller needs to ask for a guarantee from the manufacturer for this product. A quality product manufactured at the factory always has warranty documents and installation recommendations.

The principle of the check valve
In private homes and cottages, the shut-off valve can also perform the function of protecting against rodents

Features of installing a locking device

The best option for installing a shut-off valve is to repair an apartment or build a house. It is at this stage that the easiest way is to design a place for its placement and calculate the required pipe length. In this case, the locking device will be mounted during assembly of the entire sewer system.

Plastic Check Valve Installation Option
Plastic check valves for the arrangement of internal sewer networks are produced with shaped elements that facilitate installation and decorate the passage through the building structures

Most often it happens that no one plans to do repairs, but you need to install a valve. Then you should choose this device, based on the realities of your sewer system. If the shut-off valve is already selected and purchased, you can deal with the issue of its installation.

There are 2 options:

  • do everything yourself;
  • invite plumbing.

Depending on the material of the pipes in the apartment / house, the installation methods and the list of work required will be different. The price of the issue will also differ - for cast iron fittings, removing a part for installing a shut-off valve in this place is much more expensive than a similar amount of work with plastic materials.

When the option with the invitation of the master is selected, then only funds will be required to pay for his services. It is also advisable to monitor the work and check the quality of the installation so that subsequently there are no problems. It is best to contact the plumber serving the house / assigned to a certain territory.

Option for connecting to a plastic pipe
A non-return valve is connected to a plastic sewer pipe using a connecting element designed to exceed the standard pressure in the network. He does not allow leakage

If you decide to do everything on your own, you first need to look at the installation theory or read a brief briefing on installing the check valve on the sewage system.

Firstly, you need to check the purchased device in action before installing it. For this, you can use, for example, a stream of water from a tap. After testing the valve's performance and making sure that it passes water in only one direction, you can proceed to the next step.

The second step is to measure the length of the return device and mark the place of its installation, taking into account these sizes. It is important that the valve has free access - periodically it will be necessary to conduct an audit.

When everything is marked, it is necessary to remove / cut the pipe section, in place of which the locking device will be put. During installation, you need to use a sealing ring and sealant or fum tape to ensure a reliable connection and to prevent leakage.

Connecting a non-return valve using a bend
To connect the check valve at the point of changing the direction of the sewer branch, elbows with seals are used. They allow you to create an optimal bending angle and provide reliable joints.

Similarly, the rest of the shut-off valves have to be done if it is planned to install separate shut-off devices on each plumbing fixture.

The valve should be positioned correctly using the instructions that came with the device, and you can look at the red arrow indicating the direction of movement of the sewer.

When all the joints of the sewer pipe with the shut-off valve are reliably insulated, you should check the work performed in action by opening the tap or draining the water in the drain tank. If nothing leaks at the installation site, then everything has been done efficiently and you don’t have to worry.

Shut-off valve on each plumbing fixture
The option with separate blocking devices on each plumbing fixture is more convenient - so the apartment will be more securely protected in the event of a sewer blockage

When installing a shut-off valve in a common sewer pipe in the country house / cottage, you should also provide free access to it, even if it is on the street. The outer part of the sewage system together with the device and other fittings should be provided heating cable or thermal insulation system.

Device Operation Rules

In order for the non-return valve to protect the house / apartment from reverse sewage water for a long time, it is necessary to carry out its maintenance in a timely manner. Therefore, it is important to provide convenient access to it.

Hatch for revision of the device
Every 6-12 months you will have to open / unscrew the inspection cover and, if necessary, remove debris accumulating on the valve

There may be a situation when during the removal of used water there is noise, creaking and other unpleasant sounds. In this case, it is necessary to check the shut-off valve ahead of schedule - breakages in the form of worn parts or unexpected clogging are possible.

If you do not check everything in time, then with the reverse movement of sewage, the device will not be able to fulfill its purpose and dirty water will begin to come out of all plumbing fixtures.

Flooded the sink with drains
It is advisable to put check valves on each plumbing fixture, so that in case of breakdown of one of them, the rest will work

In the case when an automatic device with an electric motor is used, it is necessary to strictly adhere to the recommendations for its maintenance and to timely replace spare parts. The terms of wear of individual elements of the device are indicated by the manufacturer in the instructions.

Locking device with electric motor
It is important to follow the recommendations and service periods of locking devices with an electric motor, in order to ensure maximum protection of the house / apartment from flooding

It happens that during the audit process, wear of certain parts was found that cannot be replaced - the manufacturer does not produce the necessary parts.

Simple check valve models
In simple models with dampers, when the locking part fails, it is better to buy and put a new valve in place of the damaged

Do not repair damaged parts with improvised materials - there is no guarantee that, if necessary, a makeshift damper will cope with the pressure of drains from the pipeline in the opposite direction.

Conclusions and useful video on the topic

Video about the benefits of the check valve and the features of its installation:

The operation of the check valve in the outer part of the autonomous sewer:

The video demonstrates the action of check valves for household networks:

Some craftsmen manage to make some semblance of a check valve from improvised means. More details in this video:

Installation of the shut-off valve should be carried out at the stage of assembly of the sewer system. This is clearly demonstrated in the video:

Choosing a suitable check valve for the sewer system of your house / apartment should be subject to the peculiarities of the location and branch pipes. You can install it on your own or use plumbing - it all depends on the skills and upcoming workload.

The main thing is not to forget every 6-12 months to inspect the valve and remove any blockages that appear so that it can protect the house / apartment in the event of a backflow.

Want to talk about how to choose a check valve for sewage equipment? Do you have questions or valuable recommendations that you would like to share with site visitors? Please write comments and leave a photo on the topic in the block located under the text of the article.

Was the article helpful?
Thanks for your feedback!
No (14)
Thanks for your feedback!
Yes (86)
Visitors Comments
  1. Andrew

    For four years now, the non-return valve has allowed me to live in peace. Yes, I live on the ground floor in a nine-story building, still Soviet-built. Previously, sewers clogged at least four times a year. And what they just didn’t throw into the toilet - children's tights, bags, bones, not to mention feminine hygiene items. And then he put in his toilet a cast-iron valve, vertical and that’s all ... As cut off, now the neighbors from above periodically have a complete house trouble. The thing is simple, it is not difficult to set (it is better to call an experienced person), but it is very practical, it allows you to live like a white person, and not to clean up sewage for the entire riser.

  2. The sewage system in the apartment in Khrushchev is periodically clogged. The problem is that I have a daily schedule and I do not stay at home for a long time. Will the check valve help secure the apartment? And will it not harm the neighbors?

    • Expert
      Nikolay Fedorenko

      Hello. First of all, I advise you to solve the problem with sewage blockages by contacting the UK. Ensuring the normal operation of the sewer system is their responsibility!

      Regarding the question of installing a check valve for sewage, the presence of this device will protect your apartment from flooding with return water from the sewer pipe. Entrust the installation is better to a qualified specialist, it is even better to ask for help with choosing the most suitable model for your apartment. You don’t have to worry about the neighbors, the installation of the non-return valve will not affect them in any way, the neighbors from above will even thank you.

      I forgot to clarify - on which floor do you live? If on the first or second floor, then installing a check valve is justified. The third floor and above is already in question, since a column of sewage rarely rises above this level.

  3. Lyudmila

    We live on the 6th floor of the 9th floor. at home This week, for the second time in five years, there was flooding in the kitchen sink with return water. Calling the emergency gang and again clearing the riser with a 10-meter cable and filling the floor with black slurry from the riser. On the 5th floor, the water left the sink. What do you advise?

    • Expert
      Nikolay Fedorenko

      Hello. We advise you to draw up an official complaint to the Criminal Code, let them understand what the reason is there and solve the problem. They do not want to go to the Rospotrebnadzor, housing inspection and so on.

  4. Sofia

    I live on the 6th floor and flooded me twice. So the words about 1-2 floors are unjustified