Heat-activated closure device for pipe openings in walls

Abstract

 A device (21) for closing an aperture (31) in a partition (30) through which aperture a plastic pipe (32) passes, when the pipe is subjected to elevated temperature causing the wall of the pipe to soften, comprises at least one closure member or shutter (25) for mounting adjacent the wall of the pipe and externally of the pipe; and means (27) acting on the or each closure member or shutter to urge said member or shutter inwardly to effect closure of the aperture; the or each closure member or shutter being adapted (at edge 29) to cut through the pipe when the pipe softens at elevated temperature and/or the device further comprising a thermal link (26) connected to the or each closure member or shutter for maintaining the closure member or shutter offset from the pipe under normal conditions, the thermal link releasing the closure member or shutter when subject to a temperature exceeding a predetermined value so that said means causes the closure member(s) or shutter(s) to effect closure of the aperture.

Description

[0001] The present invention relates to a device for closing at elevated temperature an aperture in a partition, through which aperture at least one plastic pipe passes.

[0002] The term "pipe" as used herein is intended to include tubes, ducts, and other elongate hollow bodies of generally uniform cross section.

[0003] The term "plastic" is used herein to mean materials from which pipes can be made and which at elevated temperature, as under fire conditions, are soft such that they can be cut or deformed and/or burn away. Such a material is e.g. polyvinyl chloride, which is hard at normal ambient temperatures but softens at elevated temperature.

[0004] Buildings and other structures commonly have pipes passing through apertures in partitions such as walls, floors and ceilings. It is desirable that under fire conditions, the passage of combustion products (such as combustion gases and smoke) and flame through such an aperture should be prevented. To prevent passage of air through the aperture under normal conditions the aperture may be of such a size that the pipe or pipes (hereinafter referred to in the singular) passing therethrough are a close fit therein and a sealant may be provided around the pipe to provide a seal between the pipe and the partition. Under fire conditions, if the pipe is made of- plastic, it may soften and deform and/or burn away thereby allowing ready passage of combustion products and flame through the aperture even if a seal had previously been provided between the pipe and the partition. Also the combustion products and flame may enter the pipe and fluid present in the pipe may escape therefrom. The invention aims to overcome or alleviate the disadvantages referred to above.

[0005] In accordance with one aspect of the present invention, there is provided a device for closing an aperture in a partition through which aperture a plastic pipe passes, when the pipe is subjected to elevated temperature causing the wall of the pipe to soften, the device comprising: at least one closure member or shutter for mounting adjacent the wall of the pipe and externally of the pipe, the closure member or shutter being adapted to cut through the pipe when the pipe softens at elevated temperature; and means acting on the closure member(s) to urge said memeber(s) inwardly of the wall of the pipe to effect closure of the aperture when the wall of the pipe softens.

[0006] In accordance with another aspect of the invention, there is provided a device for closing an aperture in a partition through which aperture a plastic pipe passes, when the pipe is subjected to elevated temperature causing the wall of the pipe to soften, the device comprising: at least one closure member or shutter for mounting adjacent the wall of the pipe and externally of the pipe; means acting on the closure member(s) to urge said member(s) inwardly of the wall of the pipe to effect closure of the aperture; and a thermal link connected to the or each closure member or shutter for maintaining the closure member or shutter offset from the pipe under normal conditions, the thermal link releasing the closure member or shutter when subject to a temperature exceeding a predetermined value so that said means causes the shutter to effect closure of the aperture.

[0007] The closure member or shutter may carry intumescent material on at least one side thereof so that when the aperture is closed, the portion of the pipe on said at least one side of the shutter is sealingly closed by intumescence of the intumescent material.

[0008] The invention is further described below by way of example with reference to the accompanying drawings, wherein

Figure I is a front, partly cut away, view of a device according to the invention, mounted on a partition and about a plastic pipe;

Figure 2 is a section along line I - II of Figure 1; and

Figure 3 is similar to Figure 1 but shows the device and pipe after exposure to elevated temperature; and

Figure 4 is a section on an enlarged scale through a shutter of the device.

[0009] Referring to Figures 1 and 2, the device 21 shown therein comprises a frame or support 22 formed by a steel sheet in which an aperture or opening 23 has been cut.

[0010] The frame 22 has attached thereto two L-shaped flanges on opposite sides of the opening 23, the free edges 24' of the flanges being directed towards each other, the flanges thereby forming, together with the frame 22, guides or tracks in which a shutter 25 is slidable.

[0011] The shutter 25 is fastened by a thermal link 26 (shown only diagramatically in the drawings) to the frame 22. A pair of coil tension springs 27 are connected between the shutter 25 and the frame 22 and urge the shutter downwardly (as viewed in Figure 1).

[0012] Stops 28 are provided on the frame 2 as shown, or may alternatively be provided within the guides or tracks referred to above.

[0013] Referring to Figure 4, to the face 25¹ of the shutter 25 facing the frame 22 is adhered, by means of intumescent material 35, a glass fibre mat 36, which serves to reinforce the intumescent material. Edge 29 of the shutter 25 is sharpened to a knife edge.

[0014] The device 21 is mounted on a partition 30. (Figure 2) having an aperture 31 through which a plastic pipe 32 passes, the pipe being a close fit in the aperture. The pipe 12 passes through the opening 23 of the frame 22 and the shutter 25 is arranged offset from the aperture 21 and the pipe 32 with its knife edge 29 adjacent the pipe.

[0015] If a fire occurs adjacent the partition 20, the pipe 32 becomes heated and therefore softens and/or may catch light and start to burn away.

[0016] When the thermal link 26 reaches a predetermined temperature it melts or breaks releasing the shutter 25, which is then pulled by the springs 27 across the aperture 21 in the partition 20 to engage the stops 28 and thereby closing the aperture. The shutter 25 itself, as it moves across the aperture 21, deforms the pipe and/or its knife edge 29 cuts through the pipe, which has been softened by the heat of the fire. In either event, as shown in Figure 3, the aperture 71 is closed by the shutter 25 thereby preventing or at least inhibiting combustion products and flame passing through the aperture and the portions of the pipe on either side of the shutter 25 are sealingly closed by the shutter at their cut or deformed ends.

[0017] The intumescent material 35 intumesces under the heat of the fire and provides a seal between the partition 3 and the shutter 25 around the perimeter of the opening 23 and also serves to effect sealing of the pipe at its adjacent cut surface. The glass fibre mat 36 serves to apply the pressure generated by the intumescing of the intumescent material 35 over its entire area to the area of the partition 30 around the opening 23 and to the adjacent cut surface of the pipe to enhance the sealing of the opening and of the pipe at that surface. Also if the fire is on the side of the shutter 25 remote from the intumescent material 35, the intumescent material serves to inhibit transmission of heat to the cut surface of the pipe adjacent the intumescent material.

[0018] It will be appreciated that in the absence of the device 1, combustion products and flame would be able to pass through the aperture 11 as a result of the wall of the pipe 12 softening and consequently deforming and/or the wall of the pipe burning away.

[0019] If desired the intumescent material and a glass fibre mat may be similarly provided on the face 25" of the shutter 25 in addition to or instead of on the face 25' of the shutter so as to seal the pipe as its cut surface adjacent thereto in the event of a fire.

[0020] The frame 22 may be coated with intumescent material to assist in sealing the aperture 11 under fire conditions.

[0021] If desired the device 21 may be mounted between the skins of a double-skinned partition and thereby be concealed within the partition.

[0022] The openings 23 may be circular and of a diameter such that the pipe 22 is a close fit therein.

[0023] The device 21 may be modified so that it can be fitted around a pipe already installed in position and passing through an aperture in a partition.

[0024] It is to be understood that more than one plastic pipe may pass through the aperture 21 in the partition 30 and under fire conditions all such pipes are cut through or deformed by the shutter 25 as described above.

[0025] Moreover the device 21 may be used in association with a range of sizes of aperture in a partition. I.e. the device 21 is not restricted to use in association with an aperture of particular size in a partition.

[0026] It will be appreciated that only the length of the pipe 12 within and adjacent the device 21 need be of plastic: the remaining lengths of the pipe may be of metal or other material more resistant to heat.

[0027] The intumescent material referred to above may be as described in our British patent no. 1601131 or British patent applicaton no. 8421431.

Claims

1. A device for closing an aperture in a partition through which aperture a plastic pipe passes, when the pipe is subjected to elevated temperature causing the wall of the pipe to soften, the device comprising: at least one closure member or shutter for mounting adjacent the wall of the pipe and externally of the pipe the closure member or shutter being adapted to cut through the pipe when the pipe softens at elevated temperature; and means acting on the closure member(s) or shutter(s) to urge said member(s) inwardly of the wall of the pipe to effect closure of the aperture.

2. A device according to claim 1, further comprising a thermal link connected to the or each closure member or shutter for maintaining the closure member or shutter offset from the pipe under normal conditions, the thermal link releasing the closure member or shutter when subject to a temperature exceeding a predetermined value so that said means causes the closure member(s) or shutter(s) to effect closure of the pipe and/or the aperture.

3. A device according to claim 1 or 2, wherein at least one face of the or each closure member or shutter is provided with a layer of intumescent material to seal by intumescence the aperture and/or the pipe at the adjacent cut surface thereof.

4. A device according to claim 3, wherein glass fibre reinforcement is adhered to said face of the or each closure member or shutter by said intumescent material.

5. A device for closing an aperture in a partition through which aperture a plastic pipe passes, when the pipe is subjected to elevated temperature causing the wall of the pipe to soften, the .. device comprising: at least one.'closure member or shutter for mounting adjacent the wall of the pipe and externally of the pipe; means acting on the closure member(s) to urge said member(s) inwaroly of the wall of the pipe to effect closure of the aperture; arid a thermal link connected to the or each closure member or shutter for maintaining the closure member(s) or shutter(s) offset from the pipe under normal conditions, the thermal link releasing the closure member or shutter when subject to a temperature exceeding a predetermined value so that said means causes the closure meatier(s) or shutter(s) to effect closure of the aperture.

6. A device according to claim 5, wherein the or each closure member or shutter is adapted to cut through the pipe at elevated temperature when released by the thermal link.

7. A device according to claim 5 or 6, wherein at least one face of the or each closure member or shutter is provided with a layer of intumescent material to seal by intumescence the aperture and/or the pipe at the adjacent cut surface thereof.

8. A device according to claim 7, wherein glass fibre reinforcement is adhered to said face of the or each closure member or shutter by said intumescent material.

Drawing