There are several types of drainage systems and they all tend to clog sooner or later. So that the blockage does not lead to unpleasant consequences, such useful fittings as a sewer check valve are mounted. Next, we will figure out why it is needed and how it works, and home craftsmen will learn how to install a check valve for the sewage system with their own hands and receive a rating of 5 TOP manufacturers.
The sewer check valve will help save the house from flooding with drains
What is a check valve
Based on the name, it is easy to guess that this device passes a certain substance in one direction and blocks its movement in the opposite direction. Sewer valve, this is only the most famous option. In addition to the sewage system, there is a similar shut-off valve that is installed on the water supply system, heating, ventilation systems, etc.
Important! A non-return air valve is also installed in the sewer system, it is designed to normalize the pressure in the pipes, the principle of operation is the same, but the device is slightly different.
The liquid and air valve for sewage work on the same principle
Why do you need check valves
A liquid check valve is installed on the sewer system to protect housing from drains. In multi-storey buildings, the sewer system is mostly gravity and if there is a blockage somewhere, all the drains that drain from above begin to fill the riser.
Further, according to the principle of communicating vessels, as soon as the drains reach the level of the nearest toilet bowl, a fountain of everything that has been drained from above begins to beat from it. To block the fetid liquid, a sewer check valve is placed on the outlet pipe.
- In old multi-storey buildings, where the system has already worn out and blockages are not uncommon, residents of the first floors put such fittings.
The check valve in the sewage system in the apartment is especially relevant for residents of the first floors.
- In private houses equipped with septic tanks, sewer valves are installed at the exit from the basement, so that in case of flooding of the septic tank with groundwater, the drains do not go back.
- A sewage drain check valve must be installed in pressure systems, all these systems are equipped with fecal pumps, and in order to block the return flow of drains when the pump is turned off, a sewer valve is installed. You can find out about pressure systems for apartments, types of septic tanks and other nuances "HERE".
- The sewerage valve is also placed on the central drain pipe in the accumulation tank of the drainage system; without this fittings, the water will go back, which can lead to flooding of the site or the foundation of the house. The intricacies of arranging drainage in a private house are shown and told in detail "HERE".
A 110 mm sewage check valve is installed in the storage tank of the drainage system
- Both in multi-storey and in private houses, the problem of rodents periodically arises. Hungry rats can climb quite high through the sewer pipes; the check valve will prevent animals from entering the apartment.
In older homes, rats can enter housing through drain pipes.
Important! Before buying a sewage check valve, pay attention to its color - the external fittings are orange, and the valves for internal installation are gray.
The check valve of the external sewage system is orange, and for the internal one, gray
Correct and incorrect valve position
Although some engineers classify valves as horizontal and vertical, professionals do not recommend installing them on a vertical section of the pipeline, because this can lead to an emergency in an apartment located upstream of the riser.
A vertically mounted check valve accumulates debris much faster, reducing the flow rate of the pipe, leading to pressure build-up and rupture.
It is allowed to install a non-return valve:
- at the outlet into the well of the drainage system in the technical room (in the basement or on the basement floor);
- on the first floors of apartment buildings directly at the outlet of plumbing fixtures (toilet, bath, washbasin, sink);
- at the entrance to the living space after the transition element (tee or cross);
- in front of the well on the inside of the foundation.
Important! Wherever the check valve is installed, it must be installed only on horizontal sections of the pipeline (on the so-called loungers). This will prevent wastewater from climbing up the system and spilling through the toilet or bath in case of a blockage.
Another important point: the valve must be easily accessible so that the plumber can open the lid of the device and clean / repair it.
We recommend that you familiarize yourself with: Using copper pipes in various pipeline systems - pros and cons
If for some reason it is not possible to install a standard valve in the apartment (the device itself is quite bulky and in a small bathroom it can take up a lot of space), you can install a compact cuff valve that is installed on the toilet outlet pipe.
Types of sewer valves
As already mentioned, the principle of operation of such fittings is the same everywhere, but the device can be very different, now 4 types of structures are actively used:
- wafer fittings;
- lifting fittings;
- rotary fittings;
- ball constipation.
Wafer-type sewer locks
The wafer-type check valve is deservedly considered the most compact among all such constipations. The device is mounted inside the pipe between two flanges, therefore it does not require much space. But on the other hand, if such an armature is jammed, then you will have to untwist part of the system to get to the valve.
There are 2 types of wafer fittings.
- Disc constipation. In these models, the passage is blocked by a solid disc, fixed in the upper part. The disc often sinks under its own weight, without any springs, although there are exceptions. These models are considered to be among the most reliable, but they can only work in a gravity system.
Wafer check valves can be made from different materials, but the quality and price depend more on the brand than on the material.
- Bivalve center-stem wafer valves. In these models, an axis is installed in the center, on which the 2 petals are based. The leaves are pressed by a spring, the system is considered universal, the two-leaf horizontal and vertical valves are equally reliable.
Wafer check valve 100 and 110 mm are considered the most reliable
Lifting models
Here, the liquid moves in a curved path, when the drains go in the right direction, the plug is lifted and the liquid flows through. If the direction of movement changes, the spring will press the plug and the flow will be blocked.
Typically, such models are made of cast iron, they are quite powerful, the diameter of the lift check valves for the sewage system is 110 mm and higher, respectively, for private houses, and even more so for city apartments, this fittings are used extremely rarely.
Check valve cast iron - lifting type
Advice! For clean liquid, lifting structures are suitable, but it is better not to put them on the sewer drains, since blockages often occur due to the broken path of movement.
Butterfly valves
In essence, rotary or lobe systems are very similar to butterfly valves, the only difference is that there is a revision window through which the mechanism can be cleaned. There are 2 types of such fittings.
- Rigid systems. In them, the plate closes the passage under its own weight. They work flawlessly, but they are only suitable for gravity systems with a small volume of wastewater, if such fittings are placed under a pump or for large volumes, then when the petal collapses, a water hammer can occur, which is dangerous for pipes and gaskets.
- Soft valves. Without going into technical details, I will only say that the petal in them closes with a delay, as on a door closer, therefore, water hammer is excluded.
Flap check valve 50, 100 and 110 mm for domestic use is the best fit
Ball valves
The ball check valve is considered one of the most reliable, the system is trouble-free, a ball is laid inside, which rolls back in the operating position, and closes the main hole when the fluid returns.
Ball check valve is more suitable for industrial applications
Advice! When choosing a check valve for the sewerage of a house or apartment, it is better to give preference to fittings in which there is a manual blocking of the damper. A very convenient option, especially if you need to leave home for a long time, for example, to go on vacation.
Subtleties of installation
Installing a sewage check valve is not a tricky business, plus such work does not require an expensive tool, a home kit, a drill, a hacksaw, a level, a tape measure, etc. is enough. But first you need to decide where to put the check valve.
Seat selection
In this case, it all depends on where the system is most often clogged.
- If blockages usually occur in the first sewer from the house, then a 110 mm check valve is placed after the bend in the basement (before the pipe enters the wall).
Important! In multi-storey buildings, self-installation of such a valve can cause problems with the operating company. The fact is that according to SNiP 2.04.01 - 85, there must be a check valve with an electric drive and an emergency sensor in the basement, so that in case of flooding, the signal goes to the dispatcher's console. Simple fittings are installed only in rooms with round-the-clock duty.
When installed in multi-apartment buildings, the electric check valve of the sewage system may require approval
- The sewer valve in the apartment is best placed on a tee or crosspiece near the central drain into the riser.
- If there is no place near the riser for centralized fittings, then you will have to install a separate check valve for the sewage system 50 mm to the outlet towards the bathroom, kitchen, etc. And a shutter with a diameter of 100 - 110 mm for the toilet.
Check valve PVC or polypropylene is considered the best solution for an apartment or a private house
Incorrect mounting points
There are 2 recommendations here
- Before installing a check valve on the sewer, think about how you will service it, because every six months such valves need to be revised.
- In a multi-storey building, it is unnecessary to install a vertical check valve on the riser.
About vertical fittings should be said separately, installing such a shutter, you can incur a lot of problems.
- If the riser is cast-iron, then you cannot touch it at all, especially with your own hands, not every master undertakes to repair or replace the cast-iron riser. This is due to the fact that there is a danger of collapse of the entire pillar.
- Whatever the vertical check valve, it will interfere with the movement of drains, respectively, sooner or later a blockage will appear at this point.
- If drains rise from below and the valve blocks them, then in a multi-storey building, they will continue to drain from above, which will make the installation of the shutter useless.
- A sewer riser in an apartment building belongs to public structures. If you, on your own initiative, install a valve on it, then if problems arise with this fittings, you will be obliged to dismantle everything and return it to its original position at your own expense, plus pay overhead costs, for example, cleaning the basement or repairing neighbors who were flooded after installation valve.
A vertical check valve in apartment buildings should not be installed
Valve installation procedure
It is not difficult to install a check valve for sewage with your own hands. The instruction consists of several simple steps, which I tried to reflect below in the photo and video in this article.
So, it is better for a simple home craftsman to buy a horizontal check valve with a manual interlock function, made of PVC or polypropylene. The pipe diameter does not affect the installation instructions, the check valve 50, 100 and 110 mm is installed the same
- The first step is to simply collect everything as it should be.
- Then measure the distance from the valve to the outlet into the riser.
- Take a connecting adapter pipe of a suitable diameter and set aside the desired length on it, cut off the excess.
- After cutting, the edges of the pipe must be cleaned with a knife from the burrs.
Advice! You should not put a corrugation here, a lot of debris accumulates in it.
Reducer Fitting Diagram
- Now find the central axis of the drain pipe and mark 2 points on it on which the shut-off valves will be fixed.
- Drill 2 holes with a puncher and insert plastic dowels into them under the studs of the clamps.
- Pick up the studs in height and screw in the supporting clamps.
- Then insert rubber gaskets into all grooves and thickly coat all joints with sealants, after which the stop valves are finally assembled.
Installation of supporting metal clamps
- Now you just have to connect the system to the sewer and fix it firmly on metal clamps.
Fixation of shut-off valves on clamps
- Depending on the type of walls and the size of the reinforcement, the system can be fixed in three ways, the photo below shows the principle of fixation.
Three types of reinforcement fixation
Valve installation
Choosing equipment, you need to take into account all the parameters. Installation includes the following stages:
- Choose a place for installation according to the rules indicated above.
- If installed in an existing system, a section of pipe is cut out and measured according to the size of the device. When installing a new system or replacing it, the valve is installed in the right place.
- The check valve is mounted to the pipes in accordance with the instructions and the type of device.
- After installation, it is necessary to check the tightness of the connections. To do this, you need to open the water in the riser and observe the junction. If vibration is observed, it is necessary to check the quality of the connection and, if necessary, redo it.
System automation
Manufacturers are now actively working to improve the check valve system. This is mainly about automating the process. Such an automatic valve is powered by a 220 V network. Some of them have batteries, they will protect you if there is a power outage. This valve is clearly more convenient to use. First of all, the damper opens completely, which avoids the appearance of dirt bumps, which will further prevent the valve from closing completely.
check valve working principle
Principle of operation: counterflow fills the sewer pipe, when 70% fullness is reached, the probe in the middle signals this.Then the sound and light accompaniment immediately turns on, which warns of problems in the sewer system. Also at this moment the damper closes and guarantees 100% reliability.
Air valve
The air valve is another important component of the sewer system. It helps out if there is a lot of noise in the water flow in it, or there are unpleasant odors.
There may be many reasons for this, even if the water runs well, and there are no pipe blockages. In order to understand why this happens, you need to understand the principle of the sewerage system. When the water is drained, for example, in a toilet bowl, at the same moment a vacuum appears in the system. If there is no ventilation, then the noise will be high, but if it is, it will be able to equalize the pressure in the system, and the draining process will pass imperceptibly both in terms of sound and in terms of smell.
In the case of ineffective ventilation or its absence, air will go to the riser from the nearest hole, which can become both a toilet bowl and a sink, in general, any plumbing device. Thus, the odors in the home are not the most pleasant.
In order to solve this problem, an air valve should be installed in the sewer system. Its device is very simple, and its main function is to supply air to the system, to hold the valve in the system.
Sewer aerator
If the house has more than 2 floors and there is plumbing on each floor, then the system must be equipped with ventilation. Usually, a free air exchange is provided by a fan pipe, but there are times when it is not possible to install it and then an aeration or ventilation valve is installed.
Important! If the sewer system is sealed and left without ventilation, then when a large amount of water is drained, a pressure drop will occur, as a result of which water will be regularly sucked out of siphons and other hydraulic seals, which will lead to the penetration of sewer gases into the room.
An air check valve is easier to install than a liquid check valve. According to the rules of a valve with a diameter of 100 mm or more, it cuts into the system 30 cm higher, the upper outlet, for example, on the sink, but now there are a lot of small models that are installed next to the toilet or siphon.
How to install the aerator
How does the air sewer valve HL 900NECO and the like work
The aeration valve can be made by hand, the photo below gives instructions for making such fittings.
How to make a ventilation valve with your own hands
