GB2150254A

GB2150254A - Device for closing at elevated temperature a plastic pipe and/or an aperture in a partition through which aperture the pipe passes

Info

Publication number: GB2150254A
Application number: GB08427118A
Authority: GB
Inventors: Charles Barry Malcolm-Brown; Peter Mackie; Robert Alfred Tanner
Original assignee: Dixon International Ltd
Current assignee: Dixon International Ltd
Priority date: 1983-10-26
Filing date: 1984-10-26
Publication date: 1985-06-26
Also published as: GB8427118D0; GB2150254B

Abstract

A device (21) for closing a plastic pipe (32) and/or an aperture (23) in a partition through which the 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 (25) for mounting adjacent the wall of the pipe and externally of the pipe and means (27) e.g. springs acting on the closure member(s) or shutter(s) to urge said member(s) or shutter(s) inwardly of the wall of the pipe to effect closure of the pipe and/or the aperture. The closure member(s) or shutter(s) may be held in position externally of the pipe by the wall of the pipe or by a thermal link (26) which releases the closure member(s) or shutter(s) at elevated temperature. Intumescent material (35, Fig. 7 not shown) may be provided. <IMAGE>

Description

SPECIFICATION Device for closing at elevated temperature a plastic pipe andlor an aperture in a partition through which aperture the pipe passes The present invention relates to a device for closing a plastic pipe and/or an aperture in a partition, through which aperture the pipe passes, when the pipe is subjected to elevated temperature, as under fire conditions, causing the pipe to soften.

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

The term "plastic" is used herein to mean materials from which pipes can be made and which soften at elevated temperatures, e.g. polyvinyl chloride.

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 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.

In accordance with the present invention, there is provided a device for closing a plastic pipe and/or an aperture in a partition through which aperture the 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; and means acting on the closure member(s) to urge said member(s) inwardly of the wall of the pipe when the wall of the pipe softens to effect closure of the pipe.

The invention is further described below by way of example with reference to the accompanying drawings, wherein Figure 1 is a front, partly cut away, view of a first device according to the invention, mounted about a plastic pipe; Figure 2 is a section through the device, along line Il-Il of Figure 1; Figure 3 is similar to Figure 1 but shows the device and pipe after exposure to elevated temperature; and Figure 4 is a front, partly cut away, view of a second device according to the invention, mounted on a partition and about a plastic pipe; Figure 5 is a section along line IV-lV of Figure 4; and Figure 6 is similar to Figure 4 but shows the device and pipe after exposure to elevated temperature; and Figure 7 is a section on an enlarged scale through a shutter of the second device.

Referring to Figures 1 and 2, the device 1 shown therein comprises a steel frame 2 formed of two parts 3 and 4 which are fastened together by bolts 5.

The frame 2 has a front wall 14 provided by the parts 2 and 3 but no rear wall. An aperture 6 is formed in the front wall 14 of the frame and two channel-section pipe closure members 7 are provided within the frame, respectively above and below the aperture. Springs 8 are provided in the frame between upper and lower walls 9 of the frame and the pipe closure members 7. The members 7 include limbs 7' which are provided with, at least on their faces directed away from the wall 14, a layer of intumescent material 17.

The device is mounted on a partition 10 (see Figure 2) having an aperture 11 through which a pipe 12 passes, the pipe being a close fit in the aperture. The pipe 12 passes through the aperture 6 of the frame 2 and the pipe closure members 7 are arranged to act on diametrically opposite portions of the wall of the pipe, the springs 8 urging the pipe closure members in position.

If fire occurs adjacent the partition 10 the pipe becomes heated and therefore softens. The pipe closure members 7 are then driven by the springs 8 towards each other thereby squashing the pipe and closing it, as shown in Figure 3.

The limbs 7' of the pipe closure members 7 are of sufficient extent to act as shutters to close the aperture 11 in the partition 10 at the same time as the pipe is squashed.

Also, under the heat of the fire, the intumescent material intumesces to assist in closing the pipe 12 and to seal the aperture 11 in the partition 10.

It will be appreciated that only the length of the pipe 12 within and adjacent the device 1 need be of plastic: the remaining lengths of the pipe may be of metal or other material more resistant to heat.

If desired the device 1 may be mounted between the skins of a double-skinned partition and thereby concealed within the partition.

The aperture 6 may, instead of being square as shown, be circular and of a diameter such that the pipe 12 is a close fit therein.

More than one plastic pipe 12 may pass through the aperture 11.

Referring to Figures 4 and 5, 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.

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.

The shutter 25 is fastened by a thermal link 26 (shown only diagrammatically 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 4).

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

To the face 25' 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.

The device 21 is mounted on a partition 30 (Figure 5) having an aperture 31 through which a 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.

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.

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 aperature. 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, the aperture 21 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.

The intumescent material 35 intumesces under the heat of the fire and provides a seal between the partition 30 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 overs its entire area to the area of the partition 30 around the opening 23 and to the adjacent cut surface of the pipe to enhacethesealing 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.

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.

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 at its cut surface adjacent thereto in the event of a fire.

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

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

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

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.

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.

The intumescent material referred to above may be as described in our patent no. 1601131 or application no.84214311.

The intumescent material of the device of Figures 1 to 3 may be reinforced by glass fibre similarly to the intumescent material of the device of Figures 4 to7.

Claims

1. A device for closing a plastic pipe and/or an aperture in a partition through which aperture the 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; and means acting on the closure member(s) to urge said member(s) inwardly of the wall of the pipe when the wall of the pipe softens to effect closure of the pipe.

2. A device according to claim 1, wherein the closure member(s) or shutter(s) is (are) adapted to act on the pipe under normal conditions (i.e. at normal ambient temperature), the wall of the pipe holding the closure member(s) in position, softening of the wall of the pipe at elevated temperature allowing the closure member(s) or shutter(s} to move to effect closure of the pipe and/ or the aperture.

3. 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 shutter to effect closure of the pipe and/or the aperture.

4. A device according to any preceding claim, wherein the closure member(s) or shutter(s) are shaped to deform the portion(s) of the wall of the pipe on which they act towards opposite wall portion(s) of the pipe to effect closure of at least the pipe at elevated temperature.

5. A device according to any of claims 1 to 3, wherein the closure member or shutter is adapted to cut through the pipe when the pipe softens at elevated temperature.

6. A device according to claim 4 or 5, wherein at least one face of the 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.

7. A device according to claim 6, wherein glass fibre reinforcement is adhered to said face of the closure member or shutter by said intumescent material.

8. A device according to any preceding claim, wherein there are two of said closure members or shutters arranged to be urged by said means towards each other and, in use, being arranged diametrically opposite each other relative to the pipe.

9. A device for closing a plastic pipe andlor an aperture in a partition through which aperture the pipe passes when the pipe is subjected to elevated temperature causing the wall of the pipe to soften, substantially as described herein with reference to and as illustrated in Figures 1 to 3 and Figures 4 to 7 of the accompanying drawings.