CA1273302A - Composite fire stop device - Google Patents
Composite fire stop deviceInfo
- Publication number
- CA1273302A CA1273302A CA000531474A CA531474A CA1273302A CA 1273302 A CA1273302 A CA 1273302A CA 000531474 A CA000531474 A CA 000531474A CA 531474 A CA531474 A CA 531474A CA 1273302 A CA1273302 A CA 1273302A
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- CA
- Canada
- Prior art keywords
- sleeve
- assembly
- collar
- pipe
- annular
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Abstract
ABSTRACT OF THE DISCLOSURE
A fire stop collar assembly comprises a plastics sleeve (2) which fits over a plastics pipe. An annular collar (4) of intumescent material is supported by the external surface of the sleeve (2). A tension spring (8) is held under tension on an end of the sleeve (21), with a sheath of refractory fabric (6) being interposed between the spring (8) and the sleeve (2). Upon softening of the pipe and sleeve (2) in the event of a fire, the spring (8) will act to constrict the sleeve and the pipe within the refractory sheath.
A fire stop collar assembly comprises a plastics sleeve (2) which fits over a plastics pipe. An annular collar (4) of intumescent material is supported by the external surface of the sleeve (2). A tension spring (8) is held under tension on an end of the sleeve (21), with a sheath of refractory fabric (6) being interposed between the spring (8) and the sleeve (2). Upon softening of the pipe and sleeve (2) in the event of a fire, the spring (8) will act to constrict the sleeve and the pipe within the refractory sheath.
Description
~2~
., "COMPOSITE FIRE STOP DEVICE"
The present invention rela~es to device~ for the fire stopping of plastlcs pipes.
Plastlcs plpes whlch pass ~hrough fire-resisting walls or floors in a building represent a potentiàl fire hazard. In the event of a fire, the plastics pipe lS llable to melt ~hus creating a void through which hot gases may pass thereby spreading the fire to the space on tne o~her slde of the wall or floor~ In order to avoid this effec~, fire regulations may requ~re ~hat wnere a pipe passes through a fire-resisting wall or floor, means are provid~d or blocklng a void w~lch m~y be formed if the pipe should mel~.
One previously proposed method of blocking a void which may be formed by a melting pipe involves the use of a mecnanlc~l snut-off devlce comprlsing a metal closure plate, usually actuated by gravity or a spring blas to dlsplace the pipe as~lt softens and ~hereby cover the resulting hole in the wall or floor, the plate belng attached to a bracket or other mounting assembly secured to tha wall or floor adjacent the pipe; In addl~lon to simply covering the hole, it is necessary that ~ shut-off device of this type should, after reaching ~he closed position~ provide acro~ the - opening a seal of sufficient ga~ tlghtness that hot gases under pressure in the fire compartmen~ ~hould 3;~
. 2 have a sufficiently low rate of pa~sage through the now covered openiny ~hat tempera~ure rise conditions outside the fire compartmene do not e~ceed tes~
seandard~, or alternatively, tha~ no collapse due to heat softening of pla~tics pipework outgide the fire ~ compartment can occur. --The sealing tightness of such a device can be improved by application of a variety of chemic~l materials which intumesce on hea~ing and eXpand to flll any cracks or gaps which may be lef~ between the metal plate and the area around the hole. Selection of such lntumescing materials must be made with care to ensure that they do not ob'struct the movemen~ of the plate and prevent a full mechanical closure from taking place. Relevant properties of such chemical intumescing materials are the temperature a~ which intumescence begins to occur and the stiffness or strength of the foam generated. In practice it is found that intumescent chemicals of the carbon char forming type are suitable, but unfortuna~ely these materials have the characteristic of burning away at t~e higher temperatures encountered at later stages of the fire. The best of these materials would not exceed 30 minutes of effective sealing performance under fire conditions.
A further problem associated with the use of such purely mechanical shut-off devices is that for long dura~ion flre performance - say in excess o~ 2 hours -the moving shu~-off plate needs to be of heavily insulated construction so as to prevent transmission of unacceptable amounts of heat through the plate itself and thence through the opening which it covers.
In practice, mechanical devices required for performance to a 2 or 3 hour rating require to be of bulk~ construction and are objectionable both from a . ~3 - cost and fr~m a building install~tl~n point o~ view~
For this reason there is a preference to U8~ a device known as a f~re stop collar which comprises an in~ume~cent packing surrounding the pipe wlthin the floor or wall, rather than on the surface of the floor or wall.
However, with such fire stop collars, the rate-~t _ which they can operate co c105e a softened plastics pipe wlthin-a wall or floor is limited by the rate at wh~ch heat transrnission can reash the packing through the face exposed to the flre. In floor installations, it is found tha~ collars of approprlate design can functlon adequately for uPVC pipes in nominal diameter slzes from 32 mm up to 100 mm. Above 100 mm in size, the collar does no~ act to close the pipe quickly enough and needs to be supplemented by the use of a mechanical shut-off device of the ~ype descrlbed above which acts to close off the pipe opening at the time when the pipe flrst softens.
A similar consideration applies to smaller sizes of pipe when connected tO floor drains and wastes such as from showers, bathrooms, and urinals.
Wlth a view to mlnimizlng these problems, there has been proposed in our U. S. Patent No. 4,559,745 a spring choker device comprising a tension spring which lS .applied around a sheath of refractory material supported on ~he pipe, the spring being forwardly of a fire s~op collar. The spring serves to con~trtct the pipe when it softens prior to actua~lon of the fire stop collar, the pipe within the sheath then burning and foaming to form a carbon.mass which acts as a plug which blocks the.ou~er end of the-sheath to prevent ingress of hot gases. Although this arrangeme~t has been found to operate effectively in ~ 35 fire tests, its lnstallation may be rather .
,.1, ,. ~, 1 , ~ime-ccn~uming ~ prac~ice, a3 ~he spring and ~hea~h need tO be applied separately f~rom the collar.
According ~o the present invention, ~here is provided a fire seop collar as~embly compri~ing a S sleeve of heat softenable material adapted to fit over a plastics pipe, an ~nnular collar of lntume~cent ma~erial surrounding the external surface of ~he sleeve, said collar having an axial end face located inwardly of one axlal end of the sleeve whereby said sleeve defines an annular flange between ~aid axial end face and sald one end, an annular layer of flexible refractory materlal around said annular flange, and force-applying means applied around the refractory layer to apply a radially compressive force to the flange, the arrangement being such that upon sof tening of the annular flange and pipe in the event of a flre, said force-applying means acts to constrict the flange and the pipe which may subsequently burn to form a carbon mass within ~he annular layer of refractory material.
The assembly consisting of the intumescent collar and force-applylng means on a common sleeve defines an lntegral unit which can be quickly and easily installed.
Embodiments of the lnvention will now be described, by way of example only, with reference to ~ the accompanying drawlngs, in -which:
Figure 1 is an axial section through a first embodiment of a flre stop collar assembly in accordance wlth the invention;
: Figure 2 ls an end elevation of the assembly shown in Figure l; .
Figure 3 is a fragmentary axial section of a modified embodiment of the acsembly; and 7;~ 3;~
Figure 4 is a section ~howing~ schematically, a ~ypical lnstalla~lon.
As shown in Flgure 1, a fire ~top collar d~vice for application to a plastics pipe passlng through a wall, ~yp~cally a uPVC pipeg comprises a tubular support sleeve 2 of a size to fi~ over the pipe with a close-sliding fie. The support sleeve 2 is likewise composed of a plastics materlal, so as to be hea~
softenable, the sleeve typically consistlng of uPVC so as to be heat softenable at the same temperature as the plpe itself. The sleeve 2 carries an annular collar 4 of ln~umescent material, for example formed by a spirally-wound strip of relnforc~d hydrous alkal metal sllicate, such as ~hat manufactured by ~.A.S.F.
under ~he trade mark "Palusoln. The strlp m~y be coated on one or both surfaces with synthetic resin such as epoxy or polyurethane and he wound collar may be dipped in molten wax to provide a seal for the edges and any surface cracks. The axial ends of the intumescent collar 4 are displaced inwardly of the axial ends of the suppore sleeve 2, whereby the support sleeve forms annular flanges projecting beyond the ends of the collar 2.
A layer of flexible refractory fabric composed of tightly woven silica, glass or other refractory fibre, optionally coated for lmproved gas tightness, forms an annular sheath 6 interposed between the collar-4 and the support sleeve 2. The fabric of the sheath 6 projects beyond each end of the collar 2, the overall length of the fabric being greater than ~hat of the support sleeve 2, and at its axial end portions the fabric is split axially to def-ne a series of tongues 6a. A respective tension spring 8 under relatively . hlgh tension is suppor~ed on each of the ~wo annular flanges of che support sleeve 2, with the fabric .~' '' ' ... ...
~7~
sheath 6 being lnterposed between the springs 8 and ~he sleeve 2. The finger~ 6a at each axial end of the fabric sheath 6 are wrapped rearwardly around a major por~on of ~he circumference of the spring turnst wi~h the free ends of the fingers 6a being anchored by means of a rubber or other resilient ~and 10 applied under tension around the sleeve 2. The fabric fingers Sa thus act ~o hold the springs 8 on the sleeve 2.
The entlre assembly is shrunk wrap ln plastlcs film 12 whlch 1S cut away around the lnner bore of the support slee~e 2 to enable the sleeve 2 to be placed on the pipe. The film 12 acts ~o seal the intumescent collar 4 from attack by carbon dioxide in the atmosphere and also against possible water damage which may occur when the pipe is at floor level in areas susceptible ~o flooding. In addition to the sealing functicn, the plastics wrapping 12 also prevents mortar or other foreign mat~er from lodging in the coils of the springs 8 during installation and which would impede operation of the springsO
T~e fire stop collar assembly is designed ~o be mounted on the pipe by being passed over the open end of the pipe during erection of a buildlng at a stage when most of the piping is left open ended in the vicinlty of a wall ! such as a shaft wall, prior to fitting off at a later stage. Figure 4 shows a typical lnstallatlon on a plpe 20 within a-wall 22.
Rendering 24 of the wall stops short of the pipe, so rhat the end edges of the intumescen~ collar are exposed for activa~ion in the even~ of a fire. If desLred, a plastlcs flange:26 may be mounted on the pipe 20 in order to conceal the exposed edge of the collar ~ssembly; such a flange will not however, substan~ially impede heat penetration to the intumescent collar.
.~
In the event of a fire, the pipe 20 softens and the support sleeve 2 also sof~ens. The por~ion of the plpe 20 and sleeve 2 immediately surrounded by the sprlng 8 at the side of the collar assembly exposed tO
the fire lS radially con~racted under the ~ension of the spring. The plastics material within the sheath 6 ~- ~ of refractory material tends tO burn and foam ~o form a carbon mass which blocks the outer end of the sheath - - 6 and ~he cons~riction formed by the radially-constructed portion of the pipe 20 and sleeve
., "COMPOSITE FIRE STOP DEVICE"
The present invention rela~es to device~ for the fire stopping of plastlcs pipes.
Plastlcs plpes whlch pass ~hrough fire-resisting walls or floors in a building represent a potentiàl fire hazard. In the event of a fire, the plastics pipe lS llable to melt ~hus creating a void through which hot gases may pass thereby spreading the fire to the space on tne o~her slde of the wall or floor~ In order to avoid this effec~, fire regulations may requ~re ~hat wnere a pipe passes through a fire-resisting wall or floor, means are provid~d or blocklng a void w~lch m~y be formed if the pipe should mel~.
One previously proposed method of blocking a void which may be formed by a melting pipe involves the use of a mecnanlc~l snut-off devlce comprlsing a metal closure plate, usually actuated by gravity or a spring blas to dlsplace the pipe as~lt softens and ~hereby cover the resulting hole in the wall or floor, the plate belng attached to a bracket or other mounting assembly secured to tha wall or floor adjacent the pipe; In addl~lon to simply covering the hole, it is necessary that ~ shut-off device of this type should, after reaching ~he closed position~ provide acro~ the - opening a seal of sufficient ga~ tlghtness that hot gases under pressure in the fire compartmen~ ~hould 3;~
. 2 have a sufficiently low rate of pa~sage through the now covered openiny ~hat tempera~ure rise conditions outside the fire compartmene do not e~ceed tes~
seandard~, or alternatively, tha~ no collapse due to heat softening of pla~tics pipework outgide the fire ~ compartment can occur. --The sealing tightness of such a device can be improved by application of a variety of chemic~l materials which intumesce on hea~ing and eXpand to flll any cracks or gaps which may be lef~ between the metal plate and the area around the hole. Selection of such lntumescing materials must be made with care to ensure that they do not ob'struct the movemen~ of the plate and prevent a full mechanical closure from taking place. Relevant properties of such chemical intumescing materials are the temperature a~ which intumescence begins to occur and the stiffness or strength of the foam generated. In practice it is found that intumescent chemicals of the carbon char forming type are suitable, but unfortuna~ely these materials have the characteristic of burning away at t~e higher temperatures encountered at later stages of the fire. The best of these materials would not exceed 30 minutes of effective sealing performance under fire conditions.
A further problem associated with the use of such purely mechanical shut-off devices is that for long dura~ion flre performance - say in excess o~ 2 hours -the moving shu~-off plate needs to be of heavily insulated construction so as to prevent transmission of unacceptable amounts of heat through the plate itself and thence through the opening which it covers.
In practice, mechanical devices required for performance to a 2 or 3 hour rating require to be of bulk~ construction and are objectionable both from a . ~3 - cost and fr~m a building install~tl~n point o~ view~
For this reason there is a preference to U8~ a device known as a f~re stop collar which comprises an in~ume~cent packing surrounding the pipe wlthin the floor or wall, rather than on the surface of the floor or wall.
However, with such fire stop collars, the rate-~t _ which they can operate co c105e a softened plastics pipe wlthin-a wall or floor is limited by the rate at wh~ch heat transrnission can reash the packing through the face exposed to the flre. In floor installations, it is found tha~ collars of approprlate design can functlon adequately for uPVC pipes in nominal diameter slzes from 32 mm up to 100 mm. Above 100 mm in size, the collar does no~ act to close the pipe quickly enough and needs to be supplemented by the use of a mechanical shut-off device of the ~ype descrlbed above which acts to close off the pipe opening at the time when the pipe flrst softens.
A similar consideration applies to smaller sizes of pipe when connected tO floor drains and wastes such as from showers, bathrooms, and urinals.
Wlth a view to mlnimizlng these problems, there has been proposed in our U. S. Patent No. 4,559,745 a spring choker device comprising a tension spring which lS .applied around a sheath of refractory material supported on ~he pipe, the spring being forwardly of a fire s~op collar. The spring serves to con~trtct the pipe when it softens prior to actua~lon of the fire stop collar, the pipe within the sheath then burning and foaming to form a carbon.mass which acts as a plug which blocks the.ou~er end of the-sheath to prevent ingress of hot gases. Although this arrangeme~t has been found to operate effectively in ~ 35 fire tests, its lnstallation may be rather .
,.1, ,. ~, 1 , ~ime-ccn~uming ~ prac~ice, a3 ~he spring and ~hea~h need tO be applied separately f~rom the collar.
According ~o the present invention, ~here is provided a fire seop collar as~embly compri~ing a S sleeve of heat softenable material adapted to fit over a plastics pipe, an ~nnular collar of lntume~cent ma~erial surrounding the external surface of ~he sleeve, said collar having an axial end face located inwardly of one axlal end of the sleeve whereby said sleeve defines an annular flange between ~aid axial end face and sald one end, an annular layer of flexible refractory materlal around said annular flange, and force-applying means applied around the refractory layer to apply a radially compressive force to the flange, the arrangement being such that upon sof tening of the annular flange and pipe in the event of a flre, said force-applying means acts to constrict the flange and the pipe which may subsequently burn to form a carbon mass within ~he annular layer of refractory material.
The assembly consisting of the intumescent collar and force-applylng means on a common sleeve defines an lntegral unit which can be quickly and easily installed.
Embodiments of the lnvention will now be described, by way of example only, with reference to ~ the accompanying drawlngs, in -which:
Figure 1 is an axial section through a first embodiment of a flre stop collar assembly in accordance wlth the invention;
: Figure 2 ls an end elevation of the assembly shown in Figure l; .
Figure 3 is a fragmentary axial section of a modified embodiment of the acsembly; and 7;~ 3;~
Figure 4 is a section ~howing~ schematically, a ~ypical lnstalla~lon.
As shown in Flgure 1, a fire ~top collar d~vice for application to a plastics pipe passlng through a wall, ~yp~cally a uPVC pipeg comprises a tubular support sleeve 2 of a size to fi~ over the pipe with a close-sliding fie. The support sleeve 2 is likewise composed of a plastics materlal, so as to be hea~
softenable, the sleeve typically consistlng of uPVC so as to be heat softenable at the same temperature as the plpe itself. The sleeve 2 carries an annular collar 4 of ln~umescent material, for example formed by a spirally-wound strip of relnforc~d hydrous alkal metal sllicate, such as ~hat manufactured by ~.A.S.F.
under ~he trade mark "Palusoln. The strlp m~y be coated on one or both surfaces with synthetic resin such as epoxy or polyurethane and he wound collar may be dipped in molten wax to provide a seal for the edges and any surface cracks. The axial ends of the intumescent collar 4 are displaced inwardly of the axial ends of the suppore sleeve 2, whereby the support sleeve forms annular flanges projecting beyond the ends of the collar 2.
A layer of flexible refractory fabric composed of tightly woven silica, glass or other refractory fibre, optionally coated for lmproved gas tightness, forms an annular sheath 6 interposed between the collar-4 and the support sleeve 2. The fabric of the sheath 6 projects beyond each end of the collar 2, the overall length of the fabric being greater than ~hat of the support sleeve 2, and at its axial end portions the fabric is split axially to def-ne a series of tongues 6a. A respective tension spring 8 under relatively . hlgh tension is suppor~ed on each of the ~wo annular flanges of che support sleeve 2, with the fabric .~' '' ' ... ...
~7~
sheath 6 being lnterposed between the springs 8 and ~he sleeve 2. The finger~ 6a at each axial end of the fabric sheath 6 are wrapped rearwardly around a major por~on of ~he circumference of the spring turnst wi~h the free ends of the fingers 6a being anchored by means of a rubber or other resilient ~and 10 applied under tension around the sleeve 2. The fabric fingers Sa thus act ~o hold the springs 8 on the sleeve 2.
The entlre assembly is shrunk wrap ln plastlcs film 12 whlch 1S cut away around the lnner bore of the support slee~e 2 to enable the sleeve 2 to be placed on the pipe. The film 12 acts ~o seal the intumescent collar 4 from attack by carbon dioxide in the atmosphere and also against possible water damage which may occur when the pipe is at floor level in areas susceptible ~o flooding. In addition to the sealing functicn, the plastics wrapping 12 also prevents mortar or other foreign mat~er from lodging in the coils of the springs 8 during installation and which would impede operation of the springsO
T~e fire stop collar assembly is designed ~o be mounted on the pipe by being passed over the open end of the pipe during erection of a buildlng at a stage when most of the piping is left open ended in the vicinlty of a wall ! such as a shaft wall, prior to fitting off at a later stage. Figure 4 shows a typical lnstallatlon on a plpe 20 within a-wall 22.
Rendering 24 of the wall stops short of the pipe, so rhat the end edges of the intumescen~ collar are exposed for activa~ion in the even~ of a fire. If desLred, a plastlcs flange:26 may be mounted on the pipe 20 in order to conceal the exposed edge of the collar ~ssembly; such a flange will not however, substan~ially impede heat penetration to the intumescent collar.
.~
In the event of a fire, the pipe 20 softens and the support sleeve 2 also sof~ens. The por~ion of the plpe 20 and sleeve 2 immediately surrounded by the sprlng 8 at the side of the collar assembly exposed tO
the fire lS radially con~racted under the ~ension of the spring. The plastics material within the sheath 6 ~- ~ of refractory material tends tO burn and foam ~o form a carbon mass which blocks the outer end of the sheath - - 6 and ~he cons~riction formed by the radially-constructed portion of the pipe 20 and sleeve
2. Thls mass forms a plug which seals the pipe against lngress of hot gases. It is to be noted that the portlon of the sheath around the carbon mass is formed at least partially by the flngers 6a used to retain the spring 8 and which unroll from around the sprlng upon softening of the pipe 20 and sleeve 2 to extend generally axlally along the collapsed pipe.
The plug thus formed, provides a seal for a sufficlent tlme pending actlvation of the intumescent collar 4 whlch expands radially inwardly to block the vold through the wall. To facilitate intumescence throu~hout the length of the intumescent collar 4, the turns of the spirally wound intumescent layer are interleaved wi~h metal foil such as alumlnium foil to promote heat transfer wlthln the collar. The amount of metal foil is, however, kept to a minimum in order to avoid excessive heat transfer from the fire side of the wall to the other slde~of the wall.
When the 1ntumescent material expands, the initial expansion occurs ln a wedge shape which tends ~o thrust the pipe out towards the side of che wall remote from the fire. If the pipe is securely held, the rhrust will act to move the collar assembly outwardly from the side of che wall exposed to the 35 fire. To prevent ~hls action, it is necessary to ~, . ~i , anchor ehe collar assembly wlthin ~he wall. Such anchorage may be provided w~h gmaller size devices by so rendering the wall that the render overlaps the end of the assembly without completely covering ~he end of the assembly (as shown in Figure 4). In addi~ion, the~e will-be frictional adhesion to ~he mortar itself. The thrusting action described above becomes ~ ~~
ncreasingly se~ re as the diameter of the pipe lncreases. To obviate thls effect by stabilizing the turns of lntumescent material against a telescoping ac~ion, the intumescent collar 4 may be provlded with annular metal plates 30 held against its opposed axial faces as shown in Figure 3. The annular plates 30 are flanged and are held together by axial metal straps 32 distributed around the circumference of the collar 4 and bent around the flanges of che plates 30. In Flgure 3, mortar anchoring sprags 34 are at~ached to the straps 32. These sprags 34 may be used when setting the assembly into poured concrete or br1ckwork mortar, the sprags 34 being bent outwards at right angles to ~he axis of the assembly for anchorage within the concrete mortar. Instead of ~he sprags 34, tne metal plates 30 may be of greater diameter than the collar 4, whereby the device may be anchored by mor~ar between the two metal plate~.
The material from whlch the springs 8 are formed should be such that the spring should be capable of maintalnlng requisite inward radial force on the wails of the pipe 20 and sleeve 2 until softening and collapse lS complete. This perlod ranges from about 5 minutes lnto the fire for the smaller pipe diameters, and up to 10 minutes into the fire for the larger pipe diameters of 100 mm and above. Generally, ordinary low alloy spring steels would not maintain adequate _ _35 spring temper sufficiently long into the flre to be relIable for servlce, and conventional stalnlc~s steels of the 18/B type have been found satlsfactory on smaller plpe sizes. For larger pipe diameters it may be desirable to employ high alloy, precipitation hardenlng spring steels capable of high temperature servlce eo at least 600C.
-- The refract~ry fabrlc used in the assembly must be able tO deform under external spring pressure without tearing or c-racklng under fire conditions at temperatures of up tO at least 800C. The fabric must also malntaln an effectlve reslstance to passage of ho~ gases for a sufflcient time ln the flre period -for example, lO to 20 mlnutes, depending upon the pipe diameter - tO allow closure of the pipe opening to be effected by the intumescent collar 4 The assemblies described provide integral spring choker and fire stop collar assemblies which are easy to lnstall and whl~ch act to block the pipe opening prior to activatlon of the intumescent collar itself.
The embodiments have been described by way of example only, and modifications are possible within ~he scope of the lnventlon.
~ _ . , ,
The plug thus formed, provides a seal for a sufficlent tlme pending actlvation of the intumescent collar 4 whlch expands radially inwardly to block the vold through the wall. To facilitate intumescence throu~hout the length of the intumescent collar 4, the turns of the spirally wound intumescent layer are interleaved wi~h metal foil such as alumlnium foil to promote heat transfer wlthln the collar. The amount of metal foil is, however, kept to a minimum in order to avoid excessive heat transfer from the fire side of the wall to the other slde~of the wall.
When the 1ntumescent material expands, the initial expansion occurs ln a wedge shape which tends ~o thrust the pipe out towards the side of che wall remote from the fire. If the pipe is securely held, the rhrust will act to move the collar assembly outwardly from the side of che wall exposed to the 35 fire. To prevent ~hls action, it is necessary to ~, . ~i , anchor ehe collar assembly wlthin ~he wall. Such anchorage may be provided w~h gmaller size devices by so rendering the wall that the render overlaps the end of the assembly without completely covering ~he end of the assembly (as shown in Figure 4). In addi~ion, the~e will-be frictional adhesion to ~he mortar itself. The thrusting action described above becomes ~ ~~
ncreasingly se~ re as the diameter of the pipe lncreases. To obviate thls effect by stabilizing the turns of lntumescent material against a telescoping ac~ion, the intumescent collar 4 may be provlded with annular metal plates 30 held against its opposed axial faces as shown in Figure 3. The annular plates 30 are flanged and are held together by axial metal straps 32 distributed around the circumference of the collar 4 and bent around the flanges of che plates 30. In Flgure 3, mortar anchoring sprags 34 are at~ached to the straps 32. These sprags 34 may be used when setting the assembly into poured concrete or br1ckwork mortar, the sprags 34 being bent outwards at right angles to ~he axis of the assembly for anchorage within the concrete mortar. Instead of ~he sprags 34, tne metal plates 30 may be of greater diameter than the collar 4, whereby the device may be anchored by mor~ar between the two metal plate~.
The material from whlch the springs 8 are formed should be such that the spring should be capable of maintalnlng requisite inward radial force on the wails of the pipe 20 and sleeve 2 until softening and collapse lS complete. This perlod ranges from about 5 minutes lnto the fire for the smaller pipe diameters, and up to 10 minutes into the fire for the larger pipe diameters of 100 mm and above. Generally, ordinary low alloy spring steels would not maintain adequate _ _35 spring temper sufficiently long into the flre to be relIable for servlce, and conventional stalnlc~s steels of the 18/B type have been found satlsfactory on smaller plpe sizes. For larger pipe diameters it may be desirable to employ high alloy, precipitation hardenlng spring steels capable of high temperature servlce eo at least 600C.
-- The refract~ry fabrlc used in the assembly must be able tO deform under external spring pressure without tearing or c-racklng under fire conditions at temperatures of up tO at least 800C. The fabric must also malntaln an effectlve reslstance to passage of ho~ gases for a sufflcient time ln the flre period -for example, lO to 20 mlnutes, depending upon the pipe diameter - tO allow closure of the pipe opening to be effected by the intumescent collar 4 The assemblies described provide integral spring choker and fire stop collar assemblies which are easy to lnstall and whl~ch act to block the pipe opening prior to activatlon of the intumescent collar itself.
The embodiments have been described by way of example only, and modifications are possible within ~he scope of the lnventlon.
~ _ . , ,
Claims (12)
1. A fire stop composite assembly which is positionable on a plastic pipe as a composite, said assembly comprising:
a rigid sleeve of heat-softenable material adapted to be fit over a plastic pipe;
an annular collar of intumescent material surrounding an external surface of the sleeve, said collar having an axial end face located inwardly of one axial end of the sleeve;
said sleeve defining an annular flange between said axial end face of the collar and said one end of the sleeve;
an annular layer of flexible refractory material around said annular flange;
force-applying means applied around the refractory layer to apply a radially compressive force to the flange, wherein upon softening of the annular flange and pipe in the event of a fire said force-applying means acts to constrict the flange and the pipe which may subsequently burn to form a carbon mass within the annular layer of refractory material, and wherein said assembly is positionable as a composite on the pipe by slidably engaging the sleeve on the pipe.
a rigid sleeve of heat-softenable material adapted to be fit over a plastic pipe;
an annular collar of intumescent material surrounding an external surface of the sleeve, said collar having an axial end face located inwardly of one axial end of the sleeve;
said sleeve defining an annular flange between said axial end face of the collar and said one end of the sleeve;
an annular layer of flexible refractory material around said annular flange;
force-applying means applied around the refractory layer to apply a radially compressive force to the flange, wherein upon softening of the annular flange and pipe in the event of a fire said force-applying means acts to constrict the flange and the pipe which may subsequently burn to form a carbon mass within the annular layer of refractory material, and wherein said assembly is positionable as a composite on the pipe by slidably engaging the sleeve on the pipe.
2. The assembly of claim 1, wherein the annular collar is located radially inwardly of both axial ends of the sleeve such that an annular flange is defined at each end of the sleeve, and a force-applying means and annular layer of flexible refractory material are provided around each flange.
3. The assembly of claim 2, wherein the annular layer of flexible refractory material extends between the opposed ends of the sleeve such that the collar and each of the force-applying means surrounds the layer.
4. The assembly of claim 1, wherein the force-applying means comprises a tension spring applied under the tension to the flange.
5. The assembly of claim 4, wherein the spring is retained on the sleeve by split end portions of the flexible refractory material which are wrapped around the spring and anchored to the sleeve.
6. The assembly of claim 1, wherein the refractory material comprises a refractory fabric.
7. The assembly of claim 1, wherein the sleeve comprises a rigid plastic.
8. The assembly of claim 1, wherein the collar is a strip of intumescent material spirally wound, with metal foil interposed between the turns.
9. The assembly of claim 1, further comprising a shrink-wrapped plastic material disposed around the sleeve, collar and force-applying means.
10. The assembly of claim 2, further comprising a pair of annular reinforcing flanges adjacent each axial end of the collar; and means connecting the reinforcing flanges.
11. The assembly of claim 10, wherein the reinforcing flanges comprise metal flanges and the connecting means comprise metal straps extending axially between the metal flanges.
12. The assembly of claim 11, wherein the straps carry sprags for anchoring the assembly within a wall.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000531474A CA1273302A (en) | 1987-03-09 | 1987-03-09 | Composite fire stop device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000531474A CA1273302A (en) | 1987-03-09 | 1987-03-09 | Composite fire stop device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1273302A true CA1273302A (en) | 1990-08-28 |
Family
ID=4135124
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000531474A Expired CA1273302A (en) | 1987-03-09 | 1987-03-09 | Composite fire stop device |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1273302A (en) |
-
1987
- 1987-03-09 CA CA000531474A patent/CA1273302A/en not_active Expired
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKLA | Lapsed |