GB2460895A - An intumescent device - Google Patents

Abstract

This invention relates to an intumescent product for the sealing of apertures for services conduits between partitions such as walls, floors and ceilings within buildings. It is particularly, but not exclusively, concerned with sealing of such apertures upon occurrence of a fire in the vicinity of such apertures. All buildings built in the United Kingdom must conform to tire protection standards. The standards are more onerous to satisfy in the case of hotels, business premises and all commercial buildings in general. One aspect that United Kingdom legislation covers, mirrored in the legislation of other countries to a similar level is the closure of apertures between adjacent rooms, partitions comprising floors, ceilings and walls. The use of brick work, block work and concrete partitions for supporting structures is almost universal; when apertures are made within the partitions, then opportunities for the spread of tire are provided; airflow is possible through an untreated aperture. Building regulations state that tire-stopping elements must be provided to prevent the spread of fire. Typical fires-topping elements comprise packing of apertures with intumescent compounds and the use of pipe collars. The present invention seeks to provide a solution to the above problems.

Description

An Intumescent Device

Field of the Invention

This invention relates to an intumescent product for the sealing of apertures about services conduits between partitions such as walls, floors and ceilings within buildings.

It is particularly, but not exclusively, concerned with sealing of such apertures upon occurrence of a fire in the vicinity of such apertures.

Background to the Invention

All buildings built in the United Kingdom must conform with fire protection standards.

The standards are more onerous to satisfy in the case of hotels, business premises and all commercial buildings in general, than for residential premises. One aspect that United Kingdom legislation covers, mirrored in the legislation of other countries to a similar level, is the closure of apertures between adjacent rooms, partitions comprising floors, ceilings and wails. The use of brick work, block work and concrete partitions for supporting structures is thmost universth; when apertures are made within the partitions, then opportunities for the spread of fire are provided; airflow is possible through an untreated aperture. Building regulations state that fire-stopping elements must be provided to prevent the spread of fire.

Typical fire-stopping elements comprise the packing of apertures with intumescent compounds and the use of pipe collars. When an aperture is defined and service lines have been inserted, then intumescent materials or the like can be inserted; this can be difficult to apply uniformly in many situations whereby the required potential fire-stop properties of the plaster are not created; the compound is not applied to a uniform degree; cracks develop whereby the fire-stop properties are limited and not to a required standard. Pipe collars comprise flanges winch surround pipes, electrical conduits and the like -an inside surface of the collar comprises an intumescent compound which expands under elevated temperature conditions. A typical activation temperature is around 180°C. The intumescent compound expands under such conditions whereby to seal around the aperture, preventing further passage of air and any other gases, helping to reduce the spread of fire.

Intumescent substrates, when heated above their temperatures of intumescence, swell to several or many times their volume. Intumescent powders can be mixed with a thermoplastic material and subsequently utilised in moulds to form articles which, in case of fire, swell to close apertures, between a service conduit and an aperture defined within a floor, wall or partition.

Referring to Figure 1, there is shown the use of two fire-stop pipe collars either side of a partition. A typical pipe collar 12 will be two-hour fire rated and is suitable for fitting to concrete, masonry, porous concrete or stud wall constructions. Fire-stop pipe collars consist of a powder coated steel sleeve containing a flexible graphite based intumescent liner manufactured to suit the pipe-work to be fire-stopped. Integral toggle connectors, for example, are opened up and the collar is simply fitted around the plastic pipe. The toggle fastening means are closed and the collar is pushed flush to the surface of the wall or underside of floor. The collar is then securely fastened to the structure by means of fire resistant fixings threaded through fixing tabs. Any gaps of up to 25mm wide around the pipe work shothd be fiJieci with an intumescent sea'ant. For gaps greater than 25mm, a fire stop compound can be used.

When exposed to the heat of a fire, the intumescent material contained in fire-stop pipe collars will expand and exert a high pressure on the melting plastic pipe, to cause the opening to be closed off and thus preventing the spread of fire from one compartment to another.

Whilst pipe collars are available in a range of si2es for standard and non-standard pipe diameters, with certification for different types of plastic pipes including PVC, CPVC, ABS, HDPE, the proximity of the pipe with respect to other pipes and a partition may mean that fitment of a collar is not possible or that the positioning of a collar takes up a substantial amount of time leading to inefficiencies in building practice, and of course a higher cost of installation.

Fire rated mortar is typically a lightweight mortar compound which is designed to prevent the spread of fire from one compartment to another where services penetrate separating walls and floors. Fire rated mortar consists of a specially blended powder which is supplied in sacks. When mixed with water, fire rated mortar will form a trowelable or pourable mixture which can be conveniently poured into apertures having service pipes in place, but is liable to loss of the mortar before it is set in the absence of a plug or mould to retain the mortar.

A further alternative is the use of intumescent pillows as can be seen with referenceto Figure 3a and 3b. Intumescent pillows are applied as if they were sandbags, around apertures and are supported by a mesh cage in, for example, a service riser floor and are simply packed tightly in between penetrating services and the wall. Under fire conditions, the intumescent pillows expand several times their original volume to form an effective seal around the service penetrations. Intumescent pillows are suitable for use with metal pipe work, where wire mesh is employed, the overlapping basket mesh being tied together and also for electrical trunking.

Object of the Tnvention The present invention seeks to provide a solution to the above problems. The present invention seeks to provide an improved fire-stop device and apparatus and method for affixing the same which can overcome or ameliorate the above problems.

Statement of the Invention

In accordance with a first aspect of the invention, there is provided a device for shrouding a services conduit penetration aperture and services conduit about an interface in a building partition, the device comprising a first end and a second end, the first end operable to abut against a first building partition and the other end to surround, in part, a services conduit, the device comprising a heat resistant material having an intumescent material affixed upon an inside surface thereof, the device surrounding the conduit at least in part.

Typically, service conduits are positioned close to an adjacent partition and are arranged generally parallel therewith, and the device is arranged to co-operate with such adjacent partition or partitions to encircle the services conduit.

The device can be simply manufactured from one of a sheet metal, cast metal, composite plastics material, wherein the intumescent material is applied to the inside surface thereof.

Conveniently, the device is a unitary device, shaped to enclose, in part, an axial section of the conduit. In a first alternative, the device is a composite device, comprised of two or more component elements and adapted to enclose, in part, an axial section of the conduit.

Preferably, the intumescent compound has an activation temperature of between 80°C and 200°C. Conveniently, for most applications, the activation temperature is between 140° C and 190°C.

Brief description of the Figures

Some preferred embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, of which: Figure 1 shows the use of two pipe collars either side of a partition wall; Figures Ia, b show two types of pipe collar; Figure 2 illustrates a mortar-based fire stop; Figure 3a shows how fire pillows may be utilised; Figure 3b shows how fire pillows are arrange with respect to each other; Figures 4a and 4b show the use of a first embodiment of the invention; Figures 5a and 5b show the use of a second embodiment of the in invention; and, Figures 6 -9b show still further embodiments of the invention.

Detailed Description of the Preferred Embodiments

There will now be described, by way of example only, the best mode contemplated by the inventor for carrying out the present invention. In the following description, numerous specific details are set out in order to provide a complete understanding to the present invention. It will be apparent to those skilled in the art, that the present invention may be put into practice with variations of the specific.

Figures 4a -4c relate to a corner wall section 40 comprised of two wall sections 41, 42, for example constructed from bricks and mortar, and in close proximity to a ceiling 43 (shown part cut away) and a services conduit or pipe 44 passes through wall 42. The proximity of the pipe to the wall is such that it is difficult, if not impossible, to fit a pipe collar about the pipe. Figure 4b shows an example of a first embodiment of the invention, comprising a shroud 45, defined by two upstanding rectangular pieces of steel are placed such that they surround the pipe work about the aperture and extend for a length approximately corresponding to the diameter or width of the hole. For example if the duct for conduit is 10cm across, then the depth/height of the shroud would be at least 10cm. This is dependent upon the specific fire-rating required for a building or building component. Upon an inside surface of the shroud is placed an intumescent pad, comprising poly-butane and fillers of approximately 1.5 cm in thickness. These intumescent products, upon being heated to their activation temperature, will expand up to sevenfold their normal size or more. When a conduit is in place, the expanded intumescent material will close any gap around the conduit; in the event that the conduit is damaged by the fire, then the intumescent material would take the place thereof, as is known when, for example, pipe collars are fitted about a conduit which is destroyed by the heat and /or fire. The shroud could also be manufactured as a lamination of metal and graphite impregnated polymer that react at a specific activation temperature to expand and close a void. Pipes often bend or are fitted with oversized connectors that restrict the use of conventional collars.

The present invention provides a significant advantages arising from size compatibility, between collar and pipe, which will arise in the up-dating of a building which has various sized pipes that have been common for specific periods over the years but are not necessarily supported in present times. The benefit of poly-isobutylene (PIB) over acryllc and polyurethane polymers is that it is more durable than acrylic having a longer in use' maintenance free hfespan and it is easier to manufacture the end product. The PIB acts as a carrier for unexfollated graphite which is also a component of some intumescent products.

Figures 5a and Sb show a second embodiment of the invention, wherein a conduit 44 is protected by a generally "U"-shaped shroud witch is attached by screw fixing means to the wall. It will be appreciated that affixing the shroud to the wall can be accomplished relatively easily: the shroud is placed upon the wall, about the conduit 44; screw-holes (not shown in Figure 5b) are marked upon the wall via apertures defined in a flange element to the shroud; the shroud is removed, holes are defined in the wall whereby to enable screw fastening means to attach the shroud (once in place after drilling the holes) using resilient wall screw-insert means, where appropriate, to enable the shroud to be retained securely to the walls.

Turning now to Figure 6, there is shown a further shroud, 60 about a vertical wall 62 interfacing with a ceiling 63. Four screws 64 are shown retaining the shroud 60 to the wall. Intumescent compound 66 is exposed. The gap between the shroud and the ceiling 63, of the order of 0.1 -1.5 cm can be filled with an intumescent filler compound, as is known. Larger gaps can be accommodated, if necessary, but the apertures 68 for the p'acement of the screws 64 enab'e the edge 69 of the shroud to be placed in an abutting relationship with the opposite ceiling member 63. The shroud can be manufactured from mild steel, and can be painted. Alternatively the material may be a stainless steel or other metal, providing that good conduction of heat is enabled, whereby the heat capacity of the shroud does not delay operation of the intumescent material attached thereto in the event of a fire. Composite plastics may be appropriate in certain circumstances.

Figure 7 corresponds to a rectangular profile as opposed to a rounded profile of Figure 6. Here, the shroud 70 is, once again attached by screw fastening mean 64 and comprises an intumescent inside surface 76. The shroud could of course be fastened by other means, such as rivets, bolts and other forms, but this will depend upon the materials of the partitions to which the shroud is to be fastened.

Figures 8a and 8b show further designs comprising general "L" and "W" elements (in cross section) 80 and 82 respectively with intumescent material 86 arranged about an inside surface. Figure 9a and 9b comprise generally rectilinear shrouds: shroud 90 comprises a rectilinear "L" shape in cross section; composite shroud 92, 94 is made from small rectangular elements with corresponding shaped mating sections through which self-tapping screws may be placed to fixingly locate one element with respect to the other. It will be understood that, for example with reference to Figure 9b, that the elements 94, may be splayed wither inwardly or outwardly, if this assists in location of the shroud. It will be further appreciated that the shrouds may comprise many other shapes in cross-section, for example comprise an "F" shape; the shroud may accommodate multiple conduits were the spaces between adjacent conduits would not allow pipe collars or allow the use of mortar. The present invention simply provides a shroud assembly of a backing material such as a mild steel, painted or otherwise to enclose a pipe or conduit about an apertures region of the pipe as it passes through a partition, whereby the intumescent properties of the shroud enable the intumescent product to expand and fill any gaps when exposed to heat at the activation temperature of the intumescent compound, to provide fire-stop capabilities which is simple and inexpensive to install.

Some of the advantages of the present invention include the following; simpk installation; formed-in place shrouding; a system which is easily assembled and maintenance free, is unaffected by humidity and is suitable for making good around most types of service penetrations.

Claims (3)

1. Claims 1) A device for shrouding a services conduit penetration aperture and services conduit about an interface in a building partition, the device comprising a first end and a second end, the first end operable to abut against a first building partition and the other end to surround at least in part a services conduit, the device comprising a heat resistant material having an intumescent material affixed upon an inside surface thereof, the device surrounding the conduit at least in part.
2. 2) A device according to claim I wherein the device in conjunction with one or more building partitions encircles the conduit.
3. 3) A device according to claim I wherein the device is manufactured from one of a sheet metal., composite plastics material, metal cast 4 A device according to claim I wherein the device is a unitary device, shaped to enclose, in part, an axial section of the conduit.5) A device according to claim I wherein the device is a composite device, comprised of twO or more component elements and adapted to enclose, in part, an axial section of the conduit.6) A device according to claim I wherein the intumescent compound has an activation temperature of between 80°C and 200°C.7) A device according to claim 7 wherein the activation temperature is between 140° C and 190°C.