GB2323529A

GB2323529A - Seal for a fire damper

Info

Publication number: GB2323529A
Application number: GB9802498A
Authority: GB
Inventors: Roy James Jackson
Original assignee: JACKSON INT Pty Ltd
Current assignee: JACKSON INT Pty Ltd
Priority date: 1997-02-18
Filing date: 1998-02-05
Publication date: 1998-09-30
Anticipated expiration: 2018-02-05
Also published as: AU5275298A; GB2323529B; AU726578B2; GB9802498D0

Abstract

A seal 1 for fitting into and opening between a fire damper 3 and a wall 2 comprises a longitudinal, metal sheet having a flat central portion 4 and two longitudinal side portions 6 which are folded at least twice parallel to the longitudinal axis of the sheet. A first fold 8 is folded through more than 90‹ so that both the side portions 6 extend toward each other on one side of the central portion 4 . A second fold 9 is bent through more than 90‹ in an opposite direction to that of the first fold 8 so that outer parts 7 of the side portions 6 extend away from each other substantially parallel to the sheet. The first and second folds 8 and 9 have a number of spaced apart apertures which decrease the resistance of the folds to bending in situ.

Description

Seal For Fire Dampers Field of the Invention The following invention relates to fire dampers, and more particularly to seals for fire dampers.

In buildings have air-conditioning or ventilation systems, the ductwork provided through the building provides a ready means by which fire and products of combustion in any part of the building can spread throughout the building. To impede this spread of fire and products of combustion, according to Australian Standard 1668, fire dampers must be installed in wall, floor and ceiling penetrations which have been formed to pennit the installation of fire-handling systems.

As described in the forward to Australian Standard 1682 relating to the requirements for such fire dampers, fire dampers are intended to partly restore the fire resistance of a wall, floor or ceiling through which a penetration has been made. Accordingly, fire dampers must provide an effective barrier to the passage of fire and products of combustion and must be designed and constructed so that they operate under emergency conditions in extreme temperatures.

As set out in Australian Standard 1668, fire dampers must be attached to the ductwork in such a manner that any deformation of the ductwork under fire conditions will not dislodge the damper or affects its operation or performance. Furthermore, the space between the fire damper and the opening in the wall must be filled with a compressible, non-combustible material for the full thickness of the wall. This material must be compressible so as to allow the frame of the fire damper to expand as it heats up and must adequately seal this expansion gap between the frame and the wall so as to prevent the passage of fire or combustion products.

Conventionally, this gap has been filled with mineral fibre packing, which must be laboriously rammed into the space between the frame of the damper and the wall ensuring that there are no voids left. It is not yet certain whether the use of such mineral fibres poses a health problem if inhaled over a period of time.

Alternatively, the mineral fibre packing can be wrapped around the fire damper and the fire damper can be placed in the wall during construction. However, this method cannot guarantee that the correct clearance is provided for the fire damper to expand when subjected to fire conditions.

Australian Patent No. 624288 to the present applicant addressed the object of enabling the space between a frame of a fire damper and a wall to be sealed to substantially prevent fire and combustion products from passing through and yet be easier and cheaper to install than known methods. b The present invention is an improvement to the apparatus disclosed in Australian Patent No. 624288. Figure 1 of Australian Patent No. 624288 shows a separate corner angle 12 formed of a single, bent piece of sheet metal of a width substantially the same as the width of the central portion 4 of the seals 1. As the corner pieces 12 are separately fabricated, they must then be inserted into each of a pair of adjoining central portions 4 to form the seal 1.

The seals of the above referenced Australian patent show continuous longitudinal folds 8 and 9 running parallel to the longitudinal axis of the seal. As these folds are continuous, they provide a high degree of resistance to bending and thus present a resistance to the thermal expansion of damper 3 toward wall 2.

Object of the Invention It is the object of the present invention to overcome or substantially ameliorate at least one of the above disadvantages and/or more generally to provide an improved seal for fitting in an opening between a fire damper and a wall.

Disclosure of the Invention There is disclosed herein A seal for fitting in an opening between a fire damper and a wall, the seal comprising a longitudinal, metal sheet having a substantially flat central portion and two longitudinal side portions, the side portions being folded at least twice substantially parallel to the longitudinal axis of the sheet, a first of the folds being through more than 90" so that both the side portions extend toward each other on one side of the central portion of the sheet and a second fold being through more than 90" in an opposite direction to that of the first fold so that outer parts of the side portions extend away from each other substantially parallel to the sheet, the side portions thereby talking on a concertina-like configuration, characterised in that the first and second folds comprise a number of spaced apart apertures which decrease the resistance of the folds to bending in situ.

Preferably, the central portion of the sheet is of substantially the same width as the thickness of the wall into which it is to be fitted.

Preferably, the sheet is of substantially the same length as the side of the opening into which it is to be fitted.

Preferably, the outer part of one side portion extends outwardly beyond the position of the first fold.

Preferably, the seal further comprises a corner angle formed integrally with the central portion and extending substantially normally therefrom and providing a means of interengagement with another seal extending essentially normally to the central portion.

Preferably, the corner angle further comprises at least one tab adapted to engage with the central portion of an adjoining seal.

There is further disclosed herein a sealing system for fitting inSdvaFopening between a fire damper and a wall, the system comprising a plurality of the above disclosed seals for fitting into the opening along straight edges thereof, each corner angle cooperating with another of the seals so as to provide a sealing effect between two adjacent seals.

Brief Description of the Drawings A preferred form of the present invention will now be described by way of example with reference to the accompanying drawings, characterised in that: Fig. 1 is a schematic plan view of part of a blank used to form a seal; Fig. 2 is a schematic perspective view of a seal; Fig. 3 is a schematic end elevational view of the seal of Fig. 2; Fig. 4 is a schematic parts-exploded illustration of three of four seals interconnected to form a seal system; and Fig. 5 is a cross-sectional schematic view through part of an opening in a wall having a fire damper and a seal.

Detailed Description of the Invention As shown in the figures, a compressible non-combustible seal 1 for sealing an opening between a wall 2 and a fire damper 3 is formed of a longitudinal sheet of metal having a flat, central portion 4 of substantially the same width as the thickness of wall 2.

The central portion 4 is integrally formed with longitudinal side portions 5, each having an inner part 6 and an outer part 7 defined by two longitudinal folds 8 and 9 running parallel to the longitudinal axis of the seal. The first folds 8, between the central portion 4 and the inner part of the side portions 5, are greater than 90" so as to form an acute angle between the central portion 4 and the side portion 5 with both the side portions extending towards each other. The second folds 9, between the inner 6 and outer 7 parts of the side portions 5, are also greater than 90" so as to cause the outer parts 7 of the side portions 5 to extend away from each other substantially parallel to the central portion 4 of seal 1. Along each of the fold lines 8 and 9, there is provided a plurality of staggered apertures or slots 13 which reduce the rigidity of the folds to allow for easy compression of the side portions during thermal expansion of the fire damper 3. These cuts are formed along the fold lines prior to forming the blank of Fig. 1 into the configuration of Fig. 2.

Once folded, the side portions 5 have a concertina-like configuration allowing the seal to be compressed between the central portion 4 and the outer parts 7 of the side portions 5.

The outer part 7 of one side portion 5 is made to extend beyond the edge of the central portion 4. In this way, as shown in Figure 2, this extended portion of the side portion 5 can be clamped between the fire damper 3 and the retaining angle 10 so as to hold the seal 1 in place. As further shown in Figure 5, the retaining angle is arranged to be attached to the fire damper 3 and to position the damper 3 within an opening in a wall 2 by extending perpendicularly to the damper 3 along the external sides of wall 2.

It will be apparent that, when there is a fire such that the casing of damper 3 heats up and expands, it will act to force the casing of the damper 3 upwards against the outer parts 7 of the side portions 5 of seal 1. The metal seal will also expand as it heats up.

Due to the concertina-like configuration of the side portions 5 and the provisions of apertures 13 of the seal 1, the seal 1 can be compressed, thus tang up the expansion of the casing of the damper 3. It should also be noted that such compression causes the extended portion of the side portion 5 to move from between the fire damper 3 and the retaining angle 10 and therefore, in order to permit such movement, the extended portion of the seal should not be fixed to the fire damper 3 or retaining angle 10.

Although retaining angle 10 has been shown in Figure 5 in one particular configuration, it will be clear to persons skilled in the art that other types of configurations of retaining angles of channels, for example, two right angle channels, one on either side of the wall, could be used instead.

Now turning to Figure 4, there are shown three seals 1 at right angles to each other, as they would be in position around a fire damper. Of course there would normally be four such seals around the damper, but only three adjacent seals are illustrated. In order to prevent passage of fire or combustion products from around the edges of the seals 1, there is provided a corner angle 12 formed integrally with the central portion 4 though bent so as to extend essentially normally therefrom. The width of corner angle 12 is substantially the same as the width of the central portion 4 of the seals 1. The corner angle 12 can slide into adjacent seals 1 between the central portion 4 of the inner part 6 of the side portion 5 thereof. Each corner angle 12 comprises three tabs 13 extending therefrom. Each tab is bent outwardly from the corner angle 12 after a cut is made around all but one side thereof. This side forms the connection between the tabs 13 and the corner angle 12. The end of one central portion 4 remote from the corner angle 12 of that seal can be secured to an adjoining seal by interaction with the tabs 13. That is, the end of central portion 4 mentioned can be resiliently retained by the tabs against the inwardly facing surface of the corner angle of the adjoining seal. When the fire damper expands and causes the seals to compress, the mentioned end of the central portion 4 can slide in the space between the tabs and the adjoining corner angle, thus maintaining the integrity of the overall sealing effect.

It will be apparent, therefore, that the sealing system described above has the same features of compressibility and non-combustibility as the conventional mineral fibre wall, but is substantially easier to install.

The seal also has the advantage that the fire damper can be supplied to a builder with the seals already in place around the damper so that the fire damper can be built directly into a wall by a bricklayer rather than having to build a wall leaving an opening into which the damper is later filled. The shape and size of the seal can be made such that the bricklayer only needs to lay the bricks so as to contact the surface of the seal in order to make sure that adequate expansion space is provided.

Furthermore, the shape of the seals and corner angles substantially prevents the entry of brick mortar into the expansion gap provided by the seal during installation.

Therefore a brick layer can fixed the damper in position without concern that insufficient expansion space has been left around the damper. This will reduce the number of instances where the opening that has been left in a wall is later discovered to provided too small an expansion gap and the installation does not pass inspection.

Further advantage of the preferred embodiment of the invention is that by clamping the extended portion of the side portion of the seal between the brackets attached to the fire damper, the seals are held in place around the damper so that there are no loose parts which could be lost or wrongly positioned by inexperienced builders.

As used herein, the word "comprising" and its derivatives is intended to mean "includes, though is not limited to".

Claims

CLAIMS:

1. A seal for fitting in an opening between a fire damper and a wall, the seal comprising a longitudinal, metal sheet having a substantially flat central portion and two longitudinal side portions, the side portions being folded at least twice substantially parallel to the longitudinal axis of the sheet, a first of the folds being through more than 90" so that both the side portions extend toward each other on one side of the central portion of the sheet and a second fold being through more than 90" in an opposite direction to that of the first fold so that outer parts of the side portions extend away from each other substantially parallel to the sheet, the side portions thereby talking on a concertina-like configuration, characterised in that the first and second folds comprise a number of spaced apart apertures which decrease the resistance of the folds to bending in situ.

2. The seal of claim 1, characterised in that the central portion of the sheet is of substantially the same width as the thickness of the wall into which it is to be fitted.

3. The seal of claim 1 or claim 2, characterised in that the sheet is of substantially the same length as the side of the opening into which it is to be fitted.

4. The seal of any one of the preceding claims, characterised in that the outer part of one side portion extends outwardly beyond the position of the first fold.

5. The seal of any one of the preceding claims, further comprising a corner angle formed integrally with the central portion and extending substantially normally therefrom and providing a means of interengagement with another seal extending essentially normally to the central portion.

6. The seal of claim 5, characterised in that the corner angle further comprises at least one tab adapted to engage with the central portion of an adjoining seal.

7. A sealing system for fitting into an opening between a fire damper and a wall, the system comprising a plurality of the seals of any one of the preceding claims for fitting into the opening along straight edges thereof, each corner angle cooperating with another of the seals so as to provide a sealing effect between two adjacent seals.

8. A seal, substantially as hereinbefore described with reference to the accompanying drawings.

9. A sealing system, substantially as hereinbefore described with reference to the accompanying drawings.