Una red que lleva aguas sucias, con materia orgánica putrescible, genera gases malolientes y es necesario evitar que salgan olores de la red, en lugares que puedan molestar y muy especialmente en los locales interiores. Para ello se emplean dos dispositivos: los cierres inodoros, generalmente hidráulicos, y un complemento muy importante para su buen funcionamiento: un sistema de ventilación de la red, para facilitar el flujo del agua por los conductos y evacuar los gases a un lugar donde no molesten.

Odorless closures

There are two types of closures: hydraulic and mechanical. Although only hydraulic ones are usually used, the knowledge of mechanics is not to be neglected as they are used in dry climates to block the drains of walkable terraces.

The hydraulic seals, commonly known as siphons, consist of a tube shaped so that it retains a portion of clean water that is renewed in each drain cycle of the device, and prevents the passage of gases from the network to the premises. There are several types of siphon; The best known and oldest is the so-called S-siphon (in the figure) but there are also bottle, compact (very similar to the previous one, but made of plastic and smaller in size), etc. In any case, the one that works best is the S-siphon which, due to its hydraulic design, retains less solids (hair, for example) and is kept clean more easily.

There are also bell siphons, in which a half sphere or bell (now made of plastic) screwed to the closing grate of the drain, is placed with its lower edge below the level of the edge of the drain pipe, forming the closing pool. They are used on walkable terraces and in shower trays built on site.

There is also a device that serves as a siphon for several devices simultaneously, called siphon canister").

Mechanical closures, little known but widely used until half a century ago, consist of a sphere (in ancient times it was made of bronze or brass, hollow) that floats in the water and sits on a closing ring at the beginning of the downspout. When it rains, it floats, and leaves a free passage, but then it closes the passage to the gas outlet. In climates with warm and little rainy summers, the water from a siphon (on terraces one of the so-called bell ones is usually used) evaporates easily, so a mechanical one replaces it with advantage. In any case, if you have a hydraulic hood, you can avoid evaporation by placing a little vegetable oil on the surface of the retained water, which prevents evaporation.

Another mechanical device that has similar purposes is the aeration valve, which is placed at the upper end of the vents (a place where no water passes) and closes the odor outlet as long as there are no pressures or depressions in the pipes and opens when this occurs, to achieve pressure balance, avoiding desiphoning and gurgling in the siphons. They are used in ventilation outlets near inhabited areas, preventing odors except in the brief moments when they open to compensate for overpressure.

Network ventilation

For the correct functioning of the hydraulic seals, which ultimately mean a fairly efficient sealing of the network, it is necessary to have a ventilation system that prevents pressures and depressions in the ducts. Indeed, in the downpipes where toilets are discharged, a piston can form which, if the diameter is strict, will produce, when falling down the downpipe, an overpressure at the bottom and a depression at the top. These pressures can desiphon (empty water from) the hydraulic seals and, in the best of cases, produce gurgling and noises, which can be significant. Ventilation serves to balance pressures and avoid their effects.

There can be three types of ventilation:

Primary ventilation is mandatory in Spain due to compliance with the Technical Building Code (CTE).

Normally, the water from all the sewers is gathered in a final manhole, from which it is discharged into the urban network. If there is separate urban sanitation, the final manholes will be two, one for each type of sewage: stormwater and dirty water. In the case of a small treatment plant, there would be three, as has been said.

Often the sewage level is very different from the sewer outlet level. It may happen that it is much below, or it may be above.

The pipes used in this installation are currently almost all made of plastic material. Centrifuged concrete pipes (for sewers), asbestos cement (currently prohibited in most countries), cast iron, stoneware or pottery pipes (which were formerly called athanors) have been used. Normally, PVC conduits are used for hanging elements, and polypropylene conduits for buried pipes (they are usually orange in color).

A vertical pipe, which collects at least one toilet, must never have a section less than 100 mm in diameter and if it is one of the horizontal network it will not be less than 125 mm.

When it is a buried network, the pipe connections, between themselves and with the downspouts, are made in manholes that can be built in brick or prefabricated. The manholes must be easy to register, as they are essential for clearing possible blockages in the sewage network and, furthermore, the blockage often occurs in the manhole itself.

Normal facilities are planned (sized) to evacuate dirty and fecal water; In no case should non-organic matter be thrown through any of the ducts and especially things that are large in size (such as diapers, sanitary pads...) which should be thrown into the regular trash.

Contenido

Consta de:.

Water collection

The origin of the used water is a series of devices, which can be sanitary devices, or household appliances, that have a drain hole, with or without a valve, with or without a drain pump, in which the functions of hygiene, cleaning, food preparation, etc. are carried out. A water supply point should never lack a drainage point, even those that are foreseen will be used very occasionally.

In the case of stormwater, collection will depend on the type of roof, and can be done through gutters, in the case of a sloping roof, or through various types of drains, mailboxes... when it comes to terraced or flat roofs. It is also collected this way in patios.

On certain occasions it may be advisable to take rainwater to a tank (cistern), generally buried, for later use to irrigate gardens or in toilet cisterns, as a means of saving water.

For small surfaces, a pipe is often used, like a gargoyle "Gargoyle (architecture)"), which drains directly into the ground.

floor network

The pipes that collect the drains (especially when they are large diameter, but also the others) can discharge directly into the downspout or meet in a floor branch that, in turn, drains into the downspout.

When it comes to toilets for collective use, the appliance batteries (toilets, urinals and sinks) have a horizontal pipe (floor branch) that collects all the drains to take them to the downspout.

Downspouts

They are the vertical pipes that connect the floor networks with the sewers. In them the waters reach speeds of up to 8 m/s but not more, because they normally rub against the walls (actually a discharge of only water will go down close to the walls forming a spiral). They should not change diameter along their entire length, except in very tall buildings, in which, every certain height, changes in direction are made with an angle of 30° or 45°, to prevent the pour from reaching too much speed, and in which the diameter can be increased, if necessary.

Collectors

Also called atarjeas, cardes or, sometimes, collectors, which is a somewhat inappropriate name because it is excessively generic and imprecise, since it is used for many other very different devices.

The set of sewers is called horizontal network, although, as has been said, it is not exactly horizontal, since it must have a slope to facilitate the flow of water by gravity. This slope must be relatively small (0.5...5%), since used water often carries hard, abrasive solid particles (grit, for example) and, if the slope is large, the velocity will be high and erosion phenomena may occur that damage the pipes in a short time.

The horizontal network can be hung or buried. It can be hung when the building has basements (which is very common, for garages) and it is a better system because it can be seen along its entire length and it is cheaper to fix possible damages. The buried one has the problem that possible settlements of the ground can break it, and its repair is much more complicated.

When there are points where fats, organic (important kitchens) or minerals (garage drains) are poured, a grease separator device must be installed, exclusively for that sewer. Sewers that could drag solid matter (toilets, for example) should not be poured into the separator.

Una red que lleva aguas sucias, con materia orgánica putrescible, genera gases malolientes y es necesario evitar que salgan olores de la red, en lugares que puedan molestar y muy especialmente en los locales interiores. Para ello se emplean dos dispositivos: los cierres inodoros, generalmente hidráulicos, y un complemento muy importante para su buen funcionamiento: un sistema de ventilación de la red, para facilitar el flujo del agua por los conductos y evacuar los gases a un lugar donde no molesten.

Odorless closures

There are two types of closures: hydraulic and mechanical. Although only hydraulic ones are usually used, the knowledge of mechanics is not to be neglected as they are used in dry climates to block the drains of walkable terraces.

The hydraulic seals, commonly known as siphons, consist of a tube shaped so that it retains a portion of clean water that is renewed in each drain cycle of the device, and prevents the passage of gases from the network to the premises. There are several types of siphon; The best known and oldest is the so-called S-siphon (in the figure) but there are also bottle, compact (very similar to the previous one, but made of plastic and smaller in size), etc. In any case, the one that works best is the S-siphon which, due to its hydraulic design, retains less solids (hair, for example) and is kept clean more easily.

There are also bell siphons, in which a half sphere or bell (now made of plastic) screwed to the closing grate of the drain, is placed with its lower edge below the level of the edge of the drain pipe, forming the closing pool. They are used on walkable terraces and in shower trays built on site.

There is also a device that serves as a siphon for several devices simultaneously, called siphon canister").

Mechanical closures, little known but widely used until half a century ago, consist of a sphere (in ancient times it was made of bronze or brass, hollow) that floats in the water and sits on a closing ring at the beginning of the downspout. When it rains, it floats, and leaves a free passage, but then it closes the passage to the gas outlet. In climates with warm and little rainy summers, the water from a siphon (on terraces one of the so-called bell ones is usually used) evaporates easily, so a mechanical one replaces it with advantage. In any case, if you have a hydraulic hood, you can avoid evaporation by placing a little vegetable oil on the surface of the retained water, which prevents evaporation.

Another mechanical device that has similar purposes is the aeration valve, which is placed at the upper end of the vents (a place where no water passes) and closes the odor outlet as long as there are no pressures or depressions in the pipes and opens when this occurs, to achieve pressure balance, avoiding desiphoning and gurgling in the siphons. They are used in ventilation outlets near inhabited areas, preventing odors except in the brief moments when they open to compensate for overpressure.

Network ventilation

For the correct functioning of the hydraulic seals, which ultimately mean a fairly efficient sealing of the network, it is necessary to have a ventilation system that prevents pressures and depressions in the ducts. Indeed, in the downpipes where toilets are discharged, a piston can form which, if the diameter is strict, will produce, when falling down the downpipe, an overpressure at the bottom and a depression at the top. These pressures can desiphon (empty water from) the hydraulic seals and, in the best of cases, produce gurgling and noises, which can be significant. Ventilation serves to balance pressures and avoid their effects.

There can be three types of ventilation:

Primary ventilation is mandatory in Spain due to compliance with the Technical Building Code (CTE).

Normally, the water from all the sewers is gathered in a final manhole, from which it is discharged into the urban network. If there is separate urban sanitation, the final manholes will be two, one for each type of sewage: stormwater and dirty water. In the case of a small treatment plant, there would be three, as has been said.

Often the sewage level is very different from the sewer outlet level. It may happen that it is much below, or it may be above.

The pipes used in this installation are currently almost all made of plastic material. Centrifuged concrete pipes (for sewers), asbestos cement (currently prohibited in most countries), cast iron, stoneware or pottery pipes (which were formerly called athanors) have been used. Normally, PVC conduits are used for hanging elements, and polypropylene conduits for buried pipes (they are usually orange in color).

A vertical pipe, which collects at least one toilet, must never have a section less than 100 mm in diameter and if it is one of the horizontal network it will not be less than 125 mm.

When it is a buried network, the pipe connections, between themselves and with the downspouts, are made in manholes that can be built in brick or prefabricated. The manholes must be easy to register, as they are essential for clearing possible blockages in the sewage network and, furthermore, the blockage often occurs in the manhole itself.

Normal facilities are planned (sized) to evacuate dirty and fecal water; In no case should non-organic matter be thrown through any of the ducts and especially things that are large in size (such as diapers, sanitary pads...) which should be thrown into the regular trash.