The sewer system does not always work perfectly. Especially when it comes to apartment buildings with worn-out communications.
The cause of many troubles with sewerage is related to the pressure difference within the system. If several plumbing outlets are connected to a common pipe at once, then, for example, flushing the toilet bowl can pull out the water seal in the sink siphon. As a result, unpleasant odors from the general system will be drawn into the hole that has appeared.
The most effective way to regulate the pressure in the pipes is the fan valve installed for the sewer. It can work both as an outlet and as an inlet. Most often, it is taken out with a special pipe to a well-ventilated place: outside the house through the roof or wall and away from windows (according to the norms, at least 4 meters).
But such a system has significant disadvantages, which mainly consist in the high cost of work and constructive complexity. So, the fan pipe is removed from the common riser and installed at the time of construction of the building.
When the fan pipe starts to work intermittently (it clogs, microcracks form in it that violate the tightness), in some places where plumbing is connected, the pressure is no longer always constant.
As opposed to a solid fan system, one of the easiest and most affordable ways to get rid of sewer odor is to install a simple vacuum valve. For its proper installation, you also need to know some secrets, but this device can provide high-quality work and quite effectively cope with 2–3 connected bathrooms.
Design features and principle of operation of the vacuum valve for sewage
You can also install a conventional vacuum-type sewer valve with your own hands. The device is sold assembled, and the only difficulty that lies in the installation is its tight connection with the sewer pipe.
The valve is perfect for installation on the sewer in a private house or apartment — where there are few bathrooms and the load on the drain is quite small. Then he will be quite effective in doing his job.
Important! The vacuum valve for the sewer or as it is also called — the aerator — must be installed in a well-ventilated area. It is desirable that there is a window 4–5 meters away. In apartments, general ventilation is suitable, the draft of which can be enhanced by an electric fan.
The principle of operation of the vacuum valve is that, according to the laws of physics, warm air rushes to the top points. The sewer pipe system also has cavities that fill with foul-smelling air. Properly planned communications are distinguished by the fact that the place of concentration of air congestion is provided with holes that would equalize pressure drops.
Another issue is that an ordinary hole would constantly bleed air, and sometimes let liquids out, causing leaks and flooding. To avoid this, the shut-off valve used for sewage is made one-way. That is, a flap is installed on it, which can let air in from the outside in the open state. In normal mode, or when the pressure inside the sewer system rises, the valve is hermetically closed.
The valve of a conventional vacuum booster is designed as simply as possible. Most often, its membrane is made of rubber and is a conventional gasket that reliably covers the technical hole in the internal sewerage system.
Interesting! The cheapest option is to use a classic rubber membrane in the valve. But in the process of work, this material can quickly become unusable and perform its functions worse. Expensive vacuum valves may use modern technology. For example, polymer compounds that have not violated the tightness of the sewer for years, without losing quality at all. Or the device is complemented by a stem, which is finely tuned to respond to pressure drops.
The valve consists of:
- internal opening for air passage;
- a rod that is configured in such a way as to fix the pressure drop in the pipes and outside, opening or closing the membrane;
- protective cover.
Schematically, the operation of the valve looks like this:
On one of the side faces of the device there is a hole for communication with the air in the room. On some models, the receptacle may be top-mounted or under a cover cap.
Inside the vacuum valve there is a hollow space through which air can move freely. In the diagram, the red arrows show the vapors from the sewer. They cannot get into the room, as they encounter an obstacle in the form of a rubber membrane (left figure). When the pressure in the pipe system drops seriously, the membrane rises due to the air pressure from the room (gray arrows). At the moment when the pressure equalizes, the rubber gasket lowers again, ensuring the tightness of the system.
Vacuum valve installation rules
According to building codes, the exhaust sewer must be a fan. This is understood on the basis of the following requirements:
- Any type of sewer system (for industrial and domestic needs) must be ventilated through risers of the same diameter as the main pipe.
- The outlet should not lead to a common shaft for ventilation, but should lead through the roof — to the street, 4 meters or more from windows and balconies.
- A fan pipe can combine several risers with a sewer.
It turns out that building codes do not regulate the installation of a simple vacuum valve. Therefore, each owner can decide on its installation independently.
Such a valve can come in handy on the lower floors of apartment buildings (where a water seal of a toilet bowl or a siphon can be sucked in) due to the frequent use of sewerage by neighbors. It is known that with intensive draining, the suction capacity of the pipe is up to 30 volumes of the water that is collected in plumbing to block odor. In this case, the valve is indispensable.
In a private house, it is also customary to install vacuum valves when several outlets are used at once in one sewer pipe (bath, 1–2 sinks, 1–2 toilets).
There are some simple tips for installing an effective air vent on your sewer. In fact, their device is practically no different from each other, but a lot depends on how well the installation is carried out.
- To begin with, the tightness of the equipment is checked. For this, a conventional bicycle or car pump is suitable. If you treat the membrane with soap or dip it in water and blow the system in the opposite direction, then the resulting air bubbles will clearly indicate that the elastic band does not close the hole as it should.
- Install the vacuum valve only in a vertical position. So it will work as efficiently as possible.
- The valve should have good air access, but the creation of quick access for repairs should not be neglected either.
- The aerator is located at least 30 centimeters above the junction with the riser. Adapters and pipe bends are used for connection.
- There are two types of aerators: 50 and 110 mm in diameter. The former are recommended to be placed on outlets from siphons and local drains, and the latter on the main sewer pipe.
- The valve can be installed directly on the pipe in two ways: by screwing it onto a pre-cut thread or using a socket treated with sealant.
Before installation, you need to turn off the water in the house, and then insert a suitable elbow adapter on the pipe. The junction of the air valve and the sewer pipe is thoroughly cleaned of contaminants in order to maintain the tightness of the system. Of the tools at hand, you need to have suitable wrenches, sealant, a metal saw.
During operation, the device practically does not require repair, since its device is as simple as possible. The only problems that sometimes arise is the wear of the rubber membrane. But changing it is usually a matter of a few minutes.
Pros and cons of a vacuum valve
The most important advantage of using a vacuum valve is that it is designed to maximize cost savings when repairing a sewer system. The fan pipe will be several times more expensive, as it requires serious redevelopment and the purchase of a large amount of materials.
- Also, a valve with a membrane will significantly improve the performance of the sewage system.
- High energy efficiency will be achieved (heat losses in the piping system will not be as high as with a fan pipe).
- Installation is easy, straightforward and fast.
But at the same time, it would be a little silly to believe that a vacuum valve is a panacea for all sewer ills. Yes, besides it, there is nothing else to use in apartment buildings where there is no fan pipe. Also, only this device will significantly reduce the estimate of a private house (where a fan riser is not entirely appropriate due to the low load on the sewer).
But the air valve is recommended to be installed when there are not so many outlets to the plumbing. Ideally two or three. Otherwise, it will not always withstand the load and the smell from the sewer will still enter the premises through the torn off hydraulic locks.