GB2108614A - Fire-seal for pipe or duct extending through wall, floor or ceiling - Google Patents

Abstract

A fire-seal for a pipe or duct extending through a wall, floor or ceiling comprises a sleeve (1) having an outer cylindrical casing (2), a perforate cylinder (4) of material of high thermal conductivity contained within the cylindrical casing, and a cylindrical layer (5) of intumescent material on the inner surface of the outer cylindrical casing and within which the perforate cylinder is embedded. The perforate cylinder is preferably of wire mesh and adjacent the inner surface of the layer of intumescent material. <IMAGE>

Description

SPECIFICATION Fire-seal for pipe or duct extending through wall, floor or ceiling The present invention relates to a fire-seal for a pipe or duct (or trunking) extending through an aperture in a wall, floor or ceiling. By a "fire-seal" in this specification we mean a device for preventing or inhibiting penetration of smoke, fumes (combustion gases) and flame through the aperture under fire conditions.

For convenience wall, floors and celings will hereinafter be referred to simply as "walls".

Under fire conditions, smoke, fumes and combustion gases are liable to penetrate through an aperture in a wall and through which a pipe or duct extends, especially where the pipe is of plastics material which softens causing the pipe to collapse when exposed to elevated temperature.

To prevent such passage of smoke, fumes and flame, it is known to provide a fire-seal in the form of a sleeve to surround the pipe or duct at or adjacent the aperture in the wall, the sleeve comprising intumescent material which when exposed to elevated temperatures intumesces (i.e.

swells to form a voluminous solid mass) to thereby provide sealing between the pipe or duct and the wall. The sleeve is formed of two semi-cylindrical sections which have to be fitted together around the pipe after it has been positioned to extend through the aperture.

The known sleeves, as described above, have proved expensive and to have a number of disadvantages in installation and use. Such disadvantages are that the sleeve either has to be fitted below or above concrete floors and ceilings or if the sleeve is to be fitted in a ceiling or floor, an outsize hole has to be left in the ceiling or floor and then made good after the sleeve (and the pipe or duct) are in their final positions.

The present invention aims to provide an improved fire-seal for pipes and ducts extending through walls.

In accordance with the present invention, there is provided a fire-seal for a pipe or duct extending through a wall, the fire-seal being in the form of a sleeve comprising an outer cylindrical casing of material of high thermal conductivity contained within the cylindrical casing, and a cylindrical layer of intumescent material on the inner surface of the outer cylindrical casing and within which the perforate cylinder is embedded.

Preferably the perforate cylinder is of wire mesh.

Preferably the perforate cylinder is adjacent the inner surface of the layer of intumescent material.

Preferably the outer cylindrical casing has radially inwardly directed end flanges, the layer of intumescent material extending from one end flange to the other end flange.

Preferably both the outer cylindrical casing and the perforate cylinder are of steel.

The invention is further described below by way of example with reference to the accompanying drawings, wherein:~ Figure 1 is a perspective view, partly cut away, of a fire-seal according to the invention; and Figure 2 is a section through the fire-seal, showing the seal in position in a horizontal partition.

Referring to the drawings, a fire-seal for a pipe or duct is in the form of a sleeve 1. The sleeve 1 comprises a cylindrical metal casing 2 having radially inwardly extending flanges 3 and 3' at its ends. A cylinder 4 of wire mesh is contained within the metal casing 2. Figure 1 shows the sleeve 1 cut away along the dashed lines to reveal the wire mesh sleeve 4 clearly.

The casing 2 also contains a thick cylindrical layer of intumescent material 5, on the inner surface of the casing 2 and extending between the flanges 3. Within the intumescent material 5 is embeded the wire mesh cylinder 4, the wire mesh cylinder being adjacent the inner surface of the layer of intumescent material.

The sleeve 1 may be manufactured as follows.

The wire mesh cylinder 4 provided with the end flange 3 but not the end flange 3' is fitted inside the metal cylinder 2. The cylinders are placed on a former of the same cross-sectional dimensions as the pipe which the sleeve is intended to surround.

The space between the former and the metal cylinder 2 is then filled with a composition which hardens to form the intumescent layer 5, the layer 5 adhering to the metal cylinder 2. The assembly thus made is removed from the former and the end flange 3' is attached to the assembly to complete the sleeve 1.

Referring to Figure 2, the sleeve 1 is installed around a pipe or duct 10 extending through an aperture in a horizontal partition 11, which forms a ceiling and/or floor. In installing the sleeve 1, the aperture may be of the same cross-sectional size as the sleeve. Alternatively and preferably, as shown, a concrete or cement screed 1 2 may be poured into the aperture to surround the sleeve 1 and, when set, to hold the sleeve in position. The pipe or duct 10 can then be slide through the bore 6 of the sleeve 1 to its desired position.

Under fire conditions, the cylinder 2 and the wire mesh 4, both of which are of metal, conduct heat rapidly throughout the intumescent material, which intumesces to form a voluminous coherent fire-resistant mass which fills any gaps which may develop around the portion of the pipe or duct 10 in the partition 11, even if the pipe or duct collapses.

The metal cylinder 2 may be painted on its outer surface with intumescent paint to provide sealing between the cylinder and the partition under fire conditions.

The sleeve 1 may be round in section for surrounding a pipe or may be square in section for surrounding a duct e.g. for electrical cables.

It will be appreciated that the sleeve 1 according to the invention can be installed into shuttering as a floor is being laid and concreted completely around. Alternatively, a hole can be left in a concrete floor of a size to take the sleeve such that making good is necessary. The sleeve can thus be installed in the floor during the making of the floor and the pipe or duct subsequently installed.

The intumescent layer used in the present invention may be the intumescent material formed on hardening or setting of the mastic or putty as described in our British patent application no.

8204488. Thus the mastic or putty may be the composition used to fill the space between the former and the metal cylinder 2 as described above.

Claims (6)

1. A fire-seal for a pipe or duct extending through a wall (as hereinbefore defined), the fireseal being in the form of a sleeve comprising an outer cylindrical casing, a perforate cylinder of material of high thermal conductivity contained within the cylindrical casing, and a cylindrical layer of intumescent material on the inner surface of the outer cylindrical casing and within which the perforate cylinder is embedded.

2. A fire-seal according to claim 1, wherein the perforate cylinder is of wire mesh.

3. A fire-seal according to either preceding claim, where the perforate cylinder is adjacent the inner surface of the layer of intumescent material.

4. A fire-seal according to any preceding claim, wherein the cylindrical casing has radially inwardly directed end flanges, the layer of intumescent material extending from one end flange to the other end flange.

5. A fire-seal according to any preceding claim, wherein both the outer cylindrical casing and the perforate cylinder are of steel.

6. A fire-seal according to claim 1, substantially as described herein with reference to and as illustrated in the accompanying drawings.