In many bathrooms there are some metal discs on the floor. But what is it? These are nothing but caps Of siphoned boxes. These represent a real waste container of the system pipes e they provide protection from the accumulation of solid material directed to the sewer system, a source of possible blockages in the pipes and limiting the rise of bad smells. At one time they were also used to inspect exhaust systems.
How the siphoned box is made
There siphoned box it’s a cylinderset inside the floor and created in conjunction with the plumbing system of which it is part. Along the lateral surface of the cylinder we find a series of holesdesigned to house all the drainage pipes from the various sanitary fixtures present, as well as the shower tray. Of all these holes, only one represents a point of exit of water from the cylinder: in fact, this point is not connected to a sanitary fixture, but rather is connected to the main drainage pipe, which will then continue its path towards the sewer.
THE entry points (from the generic pipe towards the box) and outlet (from the box towards the sewer) can be easily recognised, clearly once the protective cover of the box has been opened: in fact, the entrances are positioned in the lower area with respect to the lateral surface of the cylinder, while the exit is positioned in the upper area. Obviously the siphoned box is equipped with an airtight closing cap, which guarantees absence of physical communicationalso in terms of smells, between what happens inside the box and what happens outside. The hydraulic seal of this lid is generally ensured by an expansion rubber, present below the metal cap. The rubber, or in general the hermetic device, is adjusted via the presence of an external screw on the cover.
How the siphoned well in the bathroom works: plumbing
The siphon box has multiple functions within the home plumbing system. First of all, it should be specified that the discharge points that lead to this device they are not all those in the bathroom. In fact, both the toilet and the washing machine drain are excluded: in both cases, the presence of important solid material (also possibly formed by the presence of soap, as for the washing machine) would lead to the progressive clogging of the box.
The solid material, conveyed into the box, settles on the bottom in part, while another part is dragged by the current towards the exit, depending on the speed and flow rate of water that is conveyed into the box. Having the exhaust hole located in the upper part of the cylinder, it occurs – in ordinary conditions – the formation of a water head That “closes” the entry holes, thus obtaining a siphon effecti.e. a hydraulic disconnection that does not allow bad odors to be transmitted into the pipes.
When the flow rates become important, the siphoned box fills up to the point of reaching the drain pipe, so that there is a natural replacement of the water present in the box and a partial emptying of the accumulated solid material. The outlet tube it is then such as to send the water conveyed inside the main pipe, where the toilet and washing machine drains will also flow.
Maintenance of the siphoned box
It is important to carry out a correct maintenance of the siphoned box, as being the same source of collection of solid objects coming from the various drains it can, over time, become clogged. This could lead to poor functioning of the drains and consequent incorrect disposal of water. For this reason it is practice inspect it periodically and remove all the solid part that has stopped inside, so as to free the pipes from possible malfunctions.
As time goes by, wear of the materials could compromise the seal of the protective coverso that, when there are high flow rates, leaks could also occur from this: it is therefore important to understand the genesis of the leak in order to surgically act on the repair and restore the correct functioning of the hydraulic system. In the case of the lid, a simple solution is usually to replace it, restoring the hydraulic seal of the device.
References
Girolamo Ippolito – Notes on Hydraulic Constructions
Salvini, Soma – Water systems in buildings 2013