Sewage check valve
At times, we are faced with a situation where their contents flow in the opposite direction through the sewer pipes. The main reason for this phenomenon is a blockage in the sewer. In a private house, this can happen when the well overflows. You can avoid this kind of trouble. It is necessary to put a check valve on the sewer. This simple but effective device completely blocks the return flow of drains.
For different pipe diameters
The content of the article
Why and who needs it
The purpose of the sewage check valve is to block the flow of liquid in the opposite direction. In this regard, the main area of application is emerging - apartments on the lower floors in high-rise buildings, especially in old buildings.
In multi-storey buildings, the owners of apartments on the first floors very often have problems with toilets, from which the contents of the sewer flow out. The blockage usually occurs somewhere in the "loungers" - horizontal pipes in the basement. Then all the contents rises through the pipe to the first branch and pours out through the first available point - the toilet, spills on the floor, sometimes even bathtubs and washbasins are filled. To solve this problem, it is necessary to put a check valve on the sewer. It will cut off the return flow going to your apartment. True, the problem will appear for those who live on the floor above - fecal water can rise even there. Then they will also have to install a sewer check valve. Above this level, the drainage column usually does not rise - it pushes the plug, everything goes away.
However, residents of high floors should not be happy - they may suffer too. Sometimes blockages occur somewhere between floors. This comes mainly due to violations of the rules for operating the sewer - someone lowers objects that should not be there, they get stuck, a traffic jam forms. In this case, the toilet bowls can be “gushed” on any floor, depending on where the blockage has formed. So on any floor, except for the last one, it makes sense to put a check valve - "just in case".
Installation example in a private house
The third group of consumers is the owners of private houses. In principle, the sewerage system of a private house should be designed so that the reverse flow of drains is impossible. Even so, many people prefer to play it safe, than to then rake the foul-smelling "treasures" from the house. The check valve to the sewer in a private house also performs another function - it prevents rodents and other living creatures from penetrating through the sewer pipe.
Ventilation in the bathroom and toilet is described here.
Types of check valves and how they work
The main purpose of a check valve is to block the flow in the opposite direction. For this, a movable barrier is placed in these mechanical devices. The basic principle of operation - in a calm state, the mechanical damper is lowered down, blocking the lumen of the sewer pipe and preventing the return flow from passing. When drains appear, it rises (moves to the side), the drains go away, and it closes again. This equipment differs by the appearance of this barrier and the principle of its operation.
Rotary (petal)
A spring-loaded circular membrane (plate) is installed in sewer valves of this type. If the flow moves in the "right" direction, it turns, rising up does not interfere with the drainage.If the movement begins in the other direction, the membrane (plate) is pressed against the rim inside the valve, tightly and hermetically closing the pipe lumen. Some models have a manual shutter. This is the second diaphragm, which can be controlled using a button installed on the body.
Due to the shape of the membrane, such shut-off valves are also called petal, and sometimes you can hear the term "slamming" - this is because of the way of work - the membrane slams if there is no drain.
The figure shows how the sewer check valve works
The device itself is larger than the pipe on which it is installed. So in the pipeline there is first an expansion, and then a narrowing of the lumen, and these are potential places for the formation of blockages. To be able to quickly remove blockages, a removable cover is made in the upper part of the check valve body. By removing its problem, you can quickly fix it.
Lift check valve for sewerage
This type of shut-off device for the sewer pipe is so named because when the drains pass in the "right" direction, the shut-off element rises up. The drains press on the plate blocking the passage, compressing the spring that rises. There are no drains - the spring is unclenched, the passage is locked. When drains come from the "wrong" side, there is no way to open the passage. This is achieved by a non-linear body shape.
Diagram of a lifting sewer valve
The lift check valve is more reliable, but its design is such that it often clogs and requires periodic cleaning. Why you need to remove the cover (unscrew four bolts), clean or replace the mechanism.
Ball check valve
Another option for a locking device in a check valve is a ball. In these devices, the internal structure of the case plays an important role. Its upper part is designed so that when the drains pass, the ball rolls into a special recess in the body, opening the passage.
The structure of the ball check valve for the sewer
When it is dry in the pipe, it blocks the section, when the flow passes in the opposite direction, it blocks the pipe lumen. The main drawback of this design is the leakage of drains during flooding - the ball and the side wall of the case do not always fit perfectly, which leads to the fact that some of the drains still leak. But massive flooding and a geyser from the toilet will not be for sure.
What is an air valve in the sewer for and how to install it, read here.
Wafer
Many people like this type of check valve better because of its miniature size. This is a very small cylinder with a butterfly valve inside. It can consist of two parts, which are attached to the central rod, or it can look like a small plate, in one place with the help of a spring attached to the wall of the case.
Wafer check valve
Despite its compactness, it is better not to put this type of check valve on the sewer: this is a plumbing equipment and it will work poorly on the sewer. The second disadvantage is the impossibility of quick cleaning - the design is such that you can get to the valve only by disassembling the connection.
What are they made of and what sizes they are
The most common sewage check valves are made of plastic (PVC) and cast iron. If your sewer pipes are plastic, it makes sense to install the same valve, choosing it by size. The situation is exactly the same with cast iron. The point is not that the materials do not fit, but the need for additional adapters that make the design even more bulky.
According to the installation method, the sewerage shut-off valve can be horizontal and vertical. Choose a type depending on the installation location. It must be installed of the same diameter as the pipe, no narrowing is allowed. Accordingly, there are valves for each size. Some parameters are given in the table.
| Name / manufacturer | Diameter | Body / damper material | Application area | Price | Notes |
|---|---|---|---|---|---|
VIEGA / Germany With two valves | 110 mm | polypropylene / polypropylene | Outdoor sewerage | 150$ | Two dampers, the second with manual interlock |
CAPRICORN / Poland For internal sewerage | 50 mm | polypropylene / polypropylene | Internal sewerage | 25$ | Single valve |
Mc Alpine / Scotland Simple construction | 32,40,50,90,110 mm | plastic | Internal wiring | 11-21$ | Has small dimensions |
Capricorn / Poland With stainless steel valve | 110 mm, 160 mm | ABS / stainless steel | Universal | 53-84$ | Emergency manual closing mode |
Ostendorf / Germany German sewage check valve | 50 mm / 110 mm | PVC / PVC | Universal | 13-24$ | Emergency manual override |
Politron / Russia Russian sewer shut-off valve | 110 mm | Polypropylene | Outdoor styling | 14$ | Emergency manual override |
Politek / Russia Manufacturer Politek | 110 mm | Polypropylene | Outdoor styling | 23$ | Emergency manual override |
When and where to put
As already mentioned, a check valve for the sewer is a rather cumbersome device. In apartments, bathrooms are usually small, it is difficult to find a place, but you have to - if you don't want to have a geyser instead of a toilet.
The exact dimensions of the sewer valves depend on the diameter of the pipe on which the device is installed. For example, for a 100 diameter sewer pipe, the minimum length is 40 cm, the height and width are slightly less. Such a box must be installed in front of the entrance to the riser.
Sewer check valve installed
In this case, it is often necessary to break the floor, the already laid tiles - it is necessary to combine the holes in the housing with the pipes, center everything, follow the required angle of inclination. This prospect is especially "happy" if renovation has been recently made. In this case, there is also an option - to cut the check valve into the riser above your entrance. But for such work - interference with the general house system (the installation of plumbing fixtures on your bend does not fall under this category), and they require written permission, you will have to notify residents, cut off the water, representatives of the operating organization or the water utility will work. In general, it is still a hassle, because this method of solving the problem is used very rarely.
If there is no room for a common device, they install sewer check valves on each plumbing fixture - separately on the toilet, bath, washbasin, sink, etc. This is if pipes from each of the devices go to the riser separately. If you have only two directions - to the toilet, and then to the bathtub-washbasin-sink, etc., then it will cost to install two devices - one personal for the toilet (the diameter coincides with the diameter of the outlet pipe) and the second - common, for a branch that goes to all other devices. Its size should match the diameter of the distribution pipe, and most often it is 50 mm.
How to put the toilet with your own hands, see here.
Installation rules
The main thing to consider is the direction of movement of the drains. It is indicated by a large arrow on the body. The device must be turned so that the normal direction of the drains coincides with the arrow. Further, the installation features are as follows:
- The installation of a plastic check valve on the sewer takes place in a standard way for this type of pipe: there is a socket and a sealing rubber. The straight edge of the pipe is inserted into this socket. Such a connection is already hermetically sealed, but for greater reliability, the junction can be additionally coated with plumbing silicone.
- Installation of cast iron models - with the help of rubber bands and bolts tightening the mounting plates, there are models with sockets - for traditional installation on tow and filling the seam with sealant.
- It should be installed so that there is a possibility of free access to the lid - periodically the check valve to the sewer becomes clogged, so it must be cleaned.
It will be necessary to provide the ability to access the lid - put a removable grill
