Sectorization in service crossing – Plastic Pipes

According to the Technical Code of the  Building in its section DB-SI, we must sectionalise plastic pipes when they cross a fire area and their diameter is over 80 mm, or even those of smaller diameters that are either together or separated by less than 3 metres.

This kind of pipes, with the mentioned diameters, are mostly made of PVC. In case of fire, they are a problem because, a few minutes after the fire starts, i.e. after 80 ºC, they soften and end up collapsing at 90 or 110 ºC. This collapse means leaving a hole completely free for the passage of smoke and flame to the other side of the fire sector.

This circumstance is especially dangerous on garage roofs, that usually have very dense pipeline networks, and a high probability that, at some point, one or more vehicles will burn. Today, we encounter a multitude of garages without the correct sectoring of these plastic elements. In case of fire, these pipe holes become real chimneys of fire and smoke.

Using an intumescent product that multiplies its volume by closing the space once the plastic pipe has disappeared is the best way to sectionalise these elements. We will consider two types of solutions according to the way in which this intumescent product is applied:

1.-Intumescent Collar with a metal casing: They are placed around the plastic pipe anchored to the sectoring partition or framework. We must place one on both sides of the fire sector, except when installed in frameworks, where it only must be installed on the underside of it. At Mercor Tecresa we have developed one of the most versatile products on the market called Tecsel Collar.  This product provides us with the possibility of using it for nearly all types of plastic pipe: PVC-U, PVC-C, PE-HD, PE, ABS, SAN + PVC and PP-R. In addition, in special layouts such as the passage of a group of pipes or non-perpendicular pipes to the sectoring component, before installing the intumescent collar, we must construct a fire-resistant box with panel to allow the proper collar installation.

2.- Intumescent Collars without metal casing: these products are sold in more or less thin bands, which have to be turned around the plastic pipe and introduced into the sectoring element. It is very important to fill the gap between the sectoring element and the plastic tube with cement or plaster, so that the intumescent product expands towards the interior of the gap, thus closing the gap and not towards the exterior. For example, if it is not closed correctly and it is placed inside a ceramic or concrete vault, the intumescent product would expand in all directions and would not close the gap, thereby failing to fulfil its sectoring mission.

We have developed two products for this purpose at mercor tecresa®:

• Tecsel bands: it is a product that comes already with the appropriate measure for each diameter and fire resistance and is installed as follows:

• Multiband Tecsel: the product comes in a roll of 60 m and depending on the diameter and fire resistance required, it is necessary to give a certain turn around the element, listed in tables. It is installed as above.