GB2370987A

GB2370987A - A seal for a fire barrier

Info

Publication number: GB2370987A
Application number: GB0100826A
Authority: GB
Inventors: Stephen James Shaughnessy; Brendan Joseph Mccormack; Alan Schofield
Original assignee: FIREHALT
Current assignee: FIREHALT
Priority date: 2001-01-12
Filing date: 2001-01-12
Publication date: 2002-07-17
Also published as: GB0100826D0

Abstract

A seal for sealing penetrations through fire barriers 15 is formed from a sheet of material 1 which may be wrapped around the periphery of an object 14 or objects extending through the fire barrier 15 and includes means for gripping 4, 5 the fire barrier. The means for gripping may be provided by a plurality of tabs extending from the sheet. Means may be provided (11, 12, 13 in Fig. 6) for fastening the sheet around an object 14. The sheet may include an intumescent material (6 in Fig. 2).

Description

SEAL

The present invention relates to a seal for sealing penetrations through fire barriers.

Fire barriers are typically, but not exclusively, used to divide up cavities in buildings in order to restrict the spread of fire, heat and smoke through and within those cavities. It is common for fire barriers to have to be penetrated by various objects, typically service conduits such as pipes, duct work, cable trays or the like. In order to maintain the performance of a fire barrier, in particular the integrity of the barrier to smoke and flame and its thermal insulation properties, an adequate seal must be effected around any penetrations through the barrier.

Fire barriers take various forms, for example fire resistant boards and flexible barriers comprising mineral or glass fibres. Conventional methods of effecting seals around penetrations through fire barriers have a number of disadvantages. They may provide a somewhat unreliable seal and/or be time consuming and/or inconvenient to implement. For example, a known method for effecting a seal around a penetration through a flexible fire barrier involves making and fitting a glass fibre material cuff tightly around the penetration and to the barrier. This can be very time consuming and requires specialist skills. An alternative known method involves inserting fire resistant material into any gaps between the barrier and a penetration passing through the barrier. This method can lack durability in service and

it can be difficult to ensure that an adequate seal has been effected.

It is an object of embodiments of the present invention to overcome or at least reduce problems associated with conventional sealing of penetrations through fire barriers.

According to a first aspect of the present invention there is provided a seal for sealing penetrations through fire barriers comprising a sheet of material which may be wrapped around the periphery of an object or objects extending through a fire barrier and means for gripping the fire barrier.

The sheet preferably behaves plastically and preferably comprises a metal sheet. Mild steel is a suitable material although it is preferably treated to prevent corrosion or other degradation, for example through being coated.

Means are preferably provided for fastening the sheet around an object. The means for fastening preferably comprises a fastener which is preferably operative to join opposite ends of the sheet and/or respective ends of separate sheets together, possibly in an overlapping relationship, preferably to provide a continuous seal. The sheet may include a number of apertures extending therethrough. The apertures may be spaced apart. The means for fastening may cooperate with one or more aperture (s) in the sheet.

The means for fastening may also comprise a banding arrangement. The sheet preferably comprises an intumescent material. This may

comprise an intumescent paper and/or felt bonded to the remainder of the sheet. Alternatively and/or additionally the intumescent material may comprise a paint or coating applied to the sheet. Provision of an intumescent material, which expands on exposure to heat, results in an improvement in the seal provided around a penetration when exposed to fire.

The means for gripping is preferably formed unitarily with the sheet.

The means for gripping preferably comprises a plurality of tabs extending from the sheet. The tabs preferably extend from two opposite lateral edges of the sheet. With this arrangement the sheet may be fitted around an object or objects extending through a fire barrier so that opposite lateral edges of the sheet lie upon opposite sides respectively of the barrier. Tabs extending from the opposite lateral edges may then be bent towards and into contact with opposite sides respectively of the barrier to grip the barrier either between tabs extending from opposite edges of the sheet and/or between tabs and any other part of the sheet.

According to a second aspect of the present invention there is provided a seal for sealing penetrations through fire barriers comprising a sheet of material which may be wrapped around the periphery of an object or objects extending through a fire barrier wherein the sheet of material comprises an intumescent material.

Preferably the sheet behaves plastically and comprises a sheet of

metal, for example mild steel which is preferably treated to prevent corrosion or other degradation. Means for fastening the sheet around an object are preferably also provided. The means preferably comprise a fastener which is preferably operative to join opposite ends of the sheet and/or respective ends of separate sheets together, possibly in an overlapping relationship, preferably to provide a continuous seal. A banding arrangement could also be used.

The intumescent material may comprise an intumescent felt and/or paper which may be bonded to the remainder of the sheet. Alternatively and/or additional intumescent material may comprise an intumescent paint or coating.

Preferably, means for gripping the barrier are also provided. These are preferably formed unitarily with the sheet and may comprise tabs extending from the sheet. The tabs preferably extend from each of two opposite lateral edges of the sheet.

According to a third aspect of the present invention there is provided a method of installing a fire barrier so that an object or objects extend (s) through the barrier comprising the steps of: providing a seal comprising a sheet of material which may be wrapped around the periphery of an object or objects extending through a fire barrier and means for gripping the fire barrier; securing the seal around the periphery of the object or objects that

are to extend through the barrier ; installing the fire barrier such that the object or objects extend therethrough; and gripping the fire barrier with the means for gripping.

The seal is preferably fitted around the periphery of the object or objects such that a physical seal is formed between the seal and object or objects. The fire barrier is preferably gripped with the means for gripping such that a physical seal is formed between the seal and the fire barrier.

Seals according to the present invention may be easily fastened, without specialist skills, around an object or objects which penetrate (s) the fire barrier and to the fire barrier itself. This helps to close any gaps between the object and fire barrier and effect a seal. Provision of intumescent material enables that seal to be enhanced in the event of fire.

In order that the invention may be more clearly understood an embodiment thereof will now be described by way of example with reference to the accompanying drawings of which: Figure 1 is a plan view of a sheet of material of a seal according to the invention ; Figure 2 is an end view of a seal according to the invention comprising the sheet of Figure 1 in a bent configuration; Figure 3 is a plan view of a fastener for use with the seal of Figure 2; Figure 4 is a side view of the fastener of Figure 3;

Figure 5 is a side view of the seal of Figure 2 secured around a pipe ; Figure 6 is a cross-section of part of the seal of Figure 5 taken along the line VU-VS of Figure 5; Figure 7 is a part cross-sectional part cut-away view of the pipe and seal of Figure 5 installed in a fire barrier; Figure 8 is a part cross-sectional view of the arrangement shown in Figure 7 with the seal shown folded to grip the barrier; and Figure 9 is an end view of a seal according to the invention fitted around two pipes extending through a fire barrier.

Referring to Figures 1 and 2 a seal comprises a sheet of mild steel of gauge suitable for folding by hand, treated to resist corrosion. The sheet 1 is of a generally elongate rectangular shape having a central portion 2.

A plurality of transverse elongate apertures 3 are evenly spaced apart along the length of the central portion 2.

Extending substantially perpendicularly from opposite lateral edges of the central portion 2 are a plurality of spaced apart short 4 and long 5 tabs. The short tabs 4 all extend from one edge of the central portion 2 and are about half the length of the long tabs 5 which all extend from the opposite edge. All of the tabs 4,5 are substantially rectangular in shape with rounded corners at their free ends.

The sheet is cut in one piece from a larger flat sheet. The sheet 1 may be produced in any convenient size. In one example though it is about

1. 2 metres in length. The central portion 2 is 65mm wide. The short tabs 4 are 38mm and the long tabs 80mm in length. All the tabs are 16. 5mm wide and distributed at a pitch of 18mm.

A layer of intumescent felt or paper 6 corresponding in shape to the central portion 2 of the sheet, save that it does not include any apertures, is bonded to the underside of the central portion 2 with a suitable adhesive.

In an alternative embodiment the intumescent layer 6 includes apertures corresponding to the apertures 3 in the sheet 1. This can be achieved by bonding the intumescent layer 6 to the sheet prior to cutting of the sheet 1.

Prior to bonding of the intumescent layer 6 to the sheet, the sheet is bent along lines 7,8, 9 and 10 shown in Figure 1 to adopt the profile shown in Figure 2. The sheet is bent along line 7 so that the short tabs 4 extend substantially at right angles to the central portion 2 in a direction away from the side of the central portion 2 to which the intumescent material 6 is bonded. The sheet 1 is similarly bent along line 8, although only through about 45 . A further slight bend is introduced along line 9 in the same direction as those made along lines 7 and 8. The tip of each of the long tabs 7 is bent through substantially 900 along line 10 in the direction of the side of the sheet 1 to which the intumescent material 6 is bonded. As will be seen below the sheet is intended to be further bended along lines 8 and 9 in use.

The sheet 1 is preferably, but not essentially, bent prior to bonding of the intumescent layer 6 to reduce the risk of the intumescent layer 6 becoming damaged during bending of the sheet 1.

The apertures 3 in the sheet 1 serve several purposes. They enable opposite ends of the sheet, or part of the sheet or two sheets, to be fastened together using the fastener shown in Figures 3 and 4. Referring to these Figures the fastener comprises a piece of mild steel sheet, of the same gauge as the sheet 1, treated to prevent corrosion comprising a rectangular portion 11 with rounded corners and two tabs 12 extending from the mid-points of the two longer sides of the rectangular portion 11 respectively so as to form a cross-shape. A layer of intumescent felt or paper 13 of corresponding shape to the rectangular portion 11 is bonded to that portion with a suitable adhesive. To fasten opposite ends of the sheet 1 together the tabs 12 of the fastener are passed through respective apertures 3 located at opposite ends of the sheet 1 and folded over to lie adjacent to the sheet 1.

In use the sheet 1 is wrapped around the periphery of an object which extends or will extend through a fire barrier so that the short 4 and long 5 tabs lie on opposite sides respectively of the barrier. Figures 5 and 6 show the seal fastened around a pipe 14. It will be appreciated, however, that the seal could be fastened around objects with a different crosssection, for example rectangular. The seal could be fastened around more

than one object.

Referring to Figures 5 and 6 the central portion 2 of the sheet 1 of the seal is wrapped around the periphery of the pipe 14 with the intumescent material 6 facing the surface of the pipe. Opposite ends of the sheet 1 are fastened together by a fastener 11,12 of the type shown in Figures 3 and 4 so that the sheet 1 fits snugly around the pipe 14. The sheet 1 is preferably fitted as closely as possible around any object although provision of the intumescent layer ensures that any gaps are sealed in the event of fire. The rectangular portion 11 of the fastener is disposed between the sheet 1 and the surface of the pipe 14. The intumescent material 13 of the fastener is directed towards the pipe. The two tabs 12 of the fastener extend through apertures in opposite ends respectively of the sheet 1 and are folded back towards the rectangular portion 11 of the fastener thereby to hold the ends of the sheet 1 together. The ends of the sheet 1 approach or abut each other, they do not overlap.

Although the seal is suitable for use with any type of fire barrier it is particularly intended for use with flexible fire barriers. Figures 7 and 8 show how the seal and pipe of Figure 5 would be installed in a fire barrier 15.

Referring to these Figures the pipe 14 is shown extending through an aperture in p. flexible fire barrier 15. The aperture has been formed by making a number of cuts through the barrier 15 to form a feathered edge to the aperture. The seal is fitted around the pipe 14 such that the short

tabs 4 lie adjacent to one side of the barrier 15 and the long tabs 5 are disposed on the opposite side of the barrier 15. The excess, feathered, barrier material lies adjacent to the central portion 2 of the sheet 1.

Once the arrangement shown in Figure 7 has been achieved the long tabs 5 are folded along lines 8 and 9 of Figure 1 over the excess barrier material in order to trap the barrier material between the long tabs 5 and the central portion 2 and the short tabs 4, thus gripping the barrier 15. This establishes a physical seal between the barrier 15 and the sheet 1. The sheet 1 itself and the intumescent materials 6 and 13 establish a physical seal with the pipe 14. Thus, a physical seal is established between the pipe 14 and barrier 15.

In the event that the barrier 15 is exposed to fire the intumescent material 6,13 on the sheet 1 and fastener 11,12 will expand considerably.

The expanding material will fill any voids between the sheet 1 and the pipe 14 and flow out of opposite ends of the sheet 1 and through apertures 3 helping to fill any voids between the barrier 15 and the sheet improving sealing of the penetration and maintaining integrity of the barrier 15.

Referring to Figure 9, this shows how a seal may be fitted around two pipes 14 extending through a barrier 15. The same reference numerals are used in this Figure as in the other Figures to identify corresponding components of the seal. The two pipes 14 are adjacent one another and the seal extends around both pipes. A bolt 16 extends through apertures

in the portions of the seal extending along opposite sides of the space between the two pipes 14. The bolt 16 and an associated nut 17 threaded onto the bolt 16 are operative to urge the portions of the seal extending along opposite sides of the space between the pipes 14 together to close the space and bring the seal into contact with a greater proportion of the outside surface of each of the pipes 14.

Provision of the intumescent materials enables the seal to maintain the integrity of the barrier during the continued dynamics of a fire, which might otherwise affect the performance of the seal.

The seal enables an effective seal to be conveniently and quickly effected between a fire barrier and a penetration therethrough, compared to existing methods. The seal is similarly effective when used with flexible or rigid barriers.

The above embodiment is described by way of example only. Many variations are possible without departing from the invention.

Claims

CLAIMS 1. A seal for sealing penetrations through fire barriers comprising a sheet of material which may be wrapped around the periphery of an object or objects extending through a fire barrier and means for gripping the fire barrier.
2. A seal as claimed in claim 1, wherein the sheet is a metal sheet.
3. A seal as claimed in either claim 1 or 2, wherein means are provided for fastening the sheet around an object.
4. A seal as claimed in claim 3, wherein the means for fastening comprises a fastener which is operative to join opposite ends of the sheet and/or respective ends of separate sheets together.
5. A seal as claimed in either claim 3 or 4, wherein the sheet has a number of spaced apart apertures extending therethrough with which the means for fastening may co-operate.
6. A seal as claimed in any of claims 3 to 5, wherein the means for fastening comprises a banding arrangement.
7. A seal as claimed in any preceding claim, wherein the sheet comprises an intumescent material.
8. A seal as claimed in any preceding claim, wherein the means for gripping is formed unitarily with the sheet.
9. A seal as claimed in any preceding claim, wherein the means for gripping comprises a plurality of tabs extending from the sheet.
10. A seal for sealing penetrations through fire barriers comprising a sheet of material which may be wrapped around the periphery of an object or objects extending through a fire barrier wherein the sheet of material comprises an intumescent material.
11. A seal as claimed in claim 10, wherein the sheet is a metal sheet.
12. A seal as claimed in either claim 10 or 11, wherein means are provided for fastening the sheet around an object.
13. A seal as claimed in claim 12, wherein the means for fastening comprises a fastener which is operative to join opposite ends of the sheet and/or respective ends of separate sheets together.
14. A seal as claimed in either claim 12 or 13, wherein the means for fastening comprises a banding arrangement.
15. A seal as claimed in any of claims 10 to 14 comprising means for gripping the barrier.
16. A seal as claimed in claim 15, wherein the means for gripping is formed unitarily with the sheet.
17. A seal as claimed in claim 16, wherein the means for gripping comprises tabs extending from the sheet.
18. A method of installing a fire barrier so that an object or objects extend (s) through the barrier comprising the steps of: providing a seal comprising a sheet of material which may be wrapped around the periphery of an object or objects extending through a fire barrier and means for gripping the fire barrier; securing the seal around the periphery of the object or objects that are to extend through the barrier ; installing the fire barrier such that the object or objects extend therethrough; and gripping the fire barrier with the means for gripping.
19. A method as claimed in claim 18, wherein the seal is fitted around the periphery of the object or objects such that a physical seal is formed between the seal and object or objects.
20. A method as claimed in either claim 18 or 19, wherein the fire barrier is gripped with the means for gripping such that a physical seal is formed between the seal and the fire barrier.
21. A seal substantially as herein described with reference to the accompanying drawings.