IMPROVED FIRESTOP STACK FITTING

Abstract: An improved firestop fitting with a flammable main conduit (11) and extension conduit (12) supporting a non-flam­ mable sleeve (14) and plug (16). The plug lodges into the sleeve when a harness (17) is melted by heat from a fire below the floor (100 or 101) in which the fitting is mounted which passes into the conduits. The fitting is relatively light and inexpen­ sive.

Description: According to the preamble of claims 1 and 2 the present invention relates to an improved firestop stack fitting which has a flammable conduit and extension and yet prevents the spread of fire between floors in a building. In particular, the present invention relates to a fitting which uses only a non-flammable plug and a non-flammable sleeve inside the fitting as the essential non-flammable elements which combine together to prevent the spread of fire between floors when the plug is released by the fire. U.S. Patent No. 4583565 shows the closest prior art. In this firestop stack fitting the main conduit and extension conduit were made of cast iron or some other non-flammable material. This combination works very well; however, it is expensive to manufacture. It was thought by the inventor that the conduit and extension had to be non-flammable in order to make the fitting operative. It is therefore an object of the present invention to provide an improved firestop stack fitting wherein the main conduit and extension conduit are composed of a flammable material such that the non-flammable parts are reduced to a minimum without compromising safety. Further it is an object of the present invention to provide an improved firestop stack fitting which is lighter and relatively less expensive to manufacture than the prior art fitting. This object is solved by the characterising parts of claims 1 or 2. The present invention relates to a stack fitting which prevents spead of fire through a floor of a building which comprises: a flammable, fluid carrying main conduit having a first longitudinal axis between towo opposed openings and suitable to be connected through a floor in a building to vertically oriented fluid conduit pipe between the floors; a flammable extension conduit from the main conduit positioned with a second axis at an acute angle from the longitudinal axis of the main conduit with an opening; a non-flammable plug mounted in the extension conduit on a flammable support provided in the extension conduit which is releasable by melting at a lower temperature than the conduits upon exposure on the support to heat through the main conduit from a fire in the building, in which it is arranged to be oriented, below the floor to thereby move the plug into the main conduit; Closure means for the extension conduit opening; and a non-flammable sleeve with openings at opposed ends mounted inside the main conduit below the plug and the extension conduit, wherein when the flammable support is released the plug falls into the non-flammable sleeve to close the non-flammable sleeve and prevent the spread of fire between the floors. Further the present invention relates to a building construction which prevents spread of fires between a floor of the building through a pipe which comprises: a stack fitting which prevents spread of fire which comprises: a flammable, fluid carrying main conduit having a first longitudinal axis between two opposed openings and suitable to be connected through the floor in the building to vertically oriented fluid conduit plastic pipe between floors; a flammable extension conduit from the main conduit positioned with a second axis at an acute angle from the longitudinal axis of the main conduit with an opening; a non-flammable plug mounted in the extension conduit on a flammable support provided in the extension conduit which is releasable by melting upon exposure of the support to heat through the main conduit from a fire in the building, in which it is arranged to be oriented, below the floor to thereby move the plug into the main conduit; closure means for the extension conduit opening; and a non-flammable sleeve with openings at opposed ends mounted inside the main conduit below the plug and extension conduit, wherein when the flammable support is released the plug falls into the non-flammable sleeve to close the non-flammable sleeve; a floor mounting the main conduit of the fitting so as to convey fluid through the floor; and fluid carrying pipe connected to both openings of the main conduit, and in that the flammable material is made from a material which melts at a lower temperature than the conuits. The acute angle is preferably between about 10° and 45°. The present invention will become increasingly apparent by reference to the following description and the drawings. Figure 1 is a perspective separated view of the improved fire stack fitting 10 of the present invention showing the non-flammable plug 16 and non-flammable sleeve 13 prior to release by a fire from the floor below the fitting 10. Figure 2 is a front partial cross-sectional view of the assembled fire stack fitting shown in Figure 1, particularly illustrating the position of the released plug 16 in dotted lines in sleeve 13. Figure 3 is an enlarged front partial sectional view of the unreleased plug 16 mounted on harness 17 in extension 12. Figure 4 is a front sectional view of an alternative type of coupling 30 which is pressed into a pre-formed or cored hole in a floor 101 rather than being cast in place in the manner of coupling 15 in floor 100. Figure 5 is an enlarged front partial cross-sectional view of the mounting of the sleeve 13 in a coupling 15 in the floor 100. Figures 1 to 5 show the improved fire stack fitting 10 or portions thereof. The fitting 10 includes a main conduit 11 and an integral extension conduit 12 at an acute angle c between a first longitudinal axis a-a of the conduit 11 and an axis b-b of the extension conduit 12. The conduits 11 and 12 are made of a flammable material particularly a plastic material, and generally in the form of an integral "Y" with collars or enlarged portions 11b, 11d and 12a for attaching pipe or other fittings. An iron sleeve 13 is fitted into the conduit 11 below the extension conduit 12 and is held in place by a plastic spacer tube 14 which mounts around the outside cylindrical of the sleeve 13 and is secured by solvent welding to the inner wall 11a of conduit 11 and then to the inner wall 15a of a plastic coupling 15. The sleeve 13 has an outer ring 13a which is engaged for support by one end of the spacer tube 14. The coupling 15 is mounted through a concrete floor 100 (Figures 2 and 5). The spacer tube 14 and sleeve 13 at an opposite end from inside ring 13a engage an internal ring 15b which is integrally formed inside the coupling 15. In this manner the non-flammable sleeve 13 is secured in place inside the coupling 15. The coupling 15 has external rings 15c and is cast in place in the floor 100 and held in place in the floor 100 by external rings 15c. The coupling 15 has a lower mounting flange 15d which is used to support the coupling 15 on a form (not shown) during pouring of the concrete floor 100. Figure 4 shows a coupling 30 which is pressed and secured in place with an adhesive in a cored opening in concrete floor 101. An upper flange 30a provides support for the coupling 30 in the floor 101. The sleeve 13 and spacer tube 14 are mounted in the couling 30 and engage an internal ring 30b of the coupling 30 in the same manner as in coupling 15. Figures 1 to 3 show a non-flammable cone shaped plug 16 mounted on a harness 17 in the extension conduit 12. The harness 17 acts to release the plug 16 by melting. The harness 17 includes collar 17a with integral temperature crossed straps 17b and 17c. A single strap 17b or 17c is as effective and less expensive. The inside portion of the collar 17a engages a lip 16a of the plug 16 and the truncated conical apex 16b of the plug 16 is supported by straps 17b and 17c. The harness 17 is mounted in the opening 12c of the extension conduit 12 and rests on the shoulder 12b (Figure 3) of the extension conduit 12. The plug 16 rests on the harness 17 and is small enough to pass through the extension conduit 12 when the harness 17 is melted by a fire. A cap 18 closes the opening 12c of the extension conduit 12 and is sealed on the extension conduit 12 by a clamp 19 in a recess 18a of the cap 18. Essentially the mounting of the plug 16 is similar to that shown in U.S. Patent No. 4583565. The fitting 10 is coupled to pipes 102 and 103 on either side of the floor 100 or 101 which are usually made of plastic. The plastic pipe 103 is solvent welded into the coupling 15 or 30 against the ring 15b or 30b. O rings 103a can be used for additional seating. The pipe 102 is generally provided with a flexible PVC coupling rubber sleeve 104 secured by solvent welding inside a shoulder 10a of the conduit 11 and secured to pipe 102 by a clamp 105. This construction allows easy mounting of the pipes 102 and 103. In operation a fire inside pipe 103 allows heat to reach the harness 17 which melts the straps 17b and/or 17c. The plug 16 is released and lodges in the sleeve 13 to provide a fire seal between the upper and lower portions of floor 100 or 101. This prevents the spread of fire between the floors 100 or 101. Preferably the inner portion 13b of lips 13a on the sleeve 13 is chamfered to make certain that the plug 16 moves correctly and reliably into the sleeve 13. It will be appreciated that the plug 16 can have any shape although the truncated cone shape is preferred. The plug 16 could be round for instance. The essential feature is that the sleeve and plug mate together sufficiently to provide the fire seal.

Claims: 1. A stack fitting which prevents spread of fire through a floor of a building which comprises: a flammable fluid carrying main conduit (11) having a first longitudinal axis (a-a) between two opposed openings and suitable to be connected through a floor in a building to a vertically oriented fluid conduit pipe (102, 103) between the floors (100, 101); a flammable extension conduit (12) from the main conduit (11) positioned with a second axis (b-b) at an acute angle (α) from the longitudinal axis (a-a) of the main conduit (11) with an opening; a non-flammable plug (16) mounted in the extension conduit (12) on a flammable support (17) provided in the extension conduit (12) which is releaseable by melting upon exposure of the support (17) to heat through the main conduit (11) from a fire in the building, in which it is arranged to be oriented, below the floor to thereby move the plug (16) into the main conduit (11); closure means (18) for the extension conduit opening, characterised by: a non-flammable sleeve (13) with openings at opposed ends mounted inside the main conduit (11) below the plug (16) and the extension conduit (12), wherein when the flammable support (17) is released the plug falls into the non-flammable sleeve (13) to close the non-flammable sleeve (13) and prevent the spread of fire between the floors (100, 101); and in that the flammable support (17) is made from a material which melts at a lower temperature than the conduits (11, 12). 2. A building construction which prevents spread of fires between a floor of the building through a pipe which comprises a stack fitting comprising: a flammable fluid carrying main conduit (11) having a first longitudinal axis (a-a) between two opposed openings and suitable to be conneted through a floor in a building to a vertically oriented fluid conduit pipe (102, 103) between the floors (100, 101); a flammable extension conduit (12) from the main conduit (11) positioned with a second axis (b-b) at an acute angle (α) from the longitudinal axis (a-a) of the main conduit (11) with an opening; a non-flammable plug (16) mounted in the extension conduit (12) on a flammable support (17) provided in the extension conduit (12) which is releaseable by melting upon exposure of the support (17) to heat through the main conduit (11) from a fire in the building, in which it is arranged to be oriented, below the floor to thereby move the plug (16) into the main conduit (11); closure means (18) for the extension conduit opening, characterised by; a non-flammable sleeve (13) with openings at opposed ends mounted inside the main conduit (11) below the plug (16) and the extension conduit (12), wherein when the flammable support (17) is released the plug falls into the non-flammable sleeve (13) to close the non-flammable sleeve (13); a floor (100) mounting the main conduit (11) of the fitting so as to convey fluid through the floor (100); and a fluid carrying pipe (102, 103) connected to both openings of the main conduit (11); and in that the flammable support (17) is made from a material which melts at a lower temperature than the conduits (11, 12). 3. The fitting of claim 1 or 2, wherein the main conduit (11) and extension conduit (12) are integral, each having a circular internal cross-section, wherein the non-flammable sleeve (13) has a circular cross-section, wherein the plug (16) is shaped as a cone with a base and with a truncated apex positioned towards the main conduit (11) and wherein upon release the plug (16) enters into an uppermost of the opening in the sleeve (13) to close the opening. 4. The fitting of one of claims 1 to 3, wherein the plug (16) has an integral lip (16a) adjacent to the base having a diameter slightly smaller than an internal diameter of the extension conduit (12) and larger than an internal diameter of the sleeve (13) and wherein when the plug (16) is released, the lip (16a) rests on the sleeve (13) at an uppermost of the ends with the apex (16b) inside the upper most of the openings in the sleeve (13). 5. The fitting of one of claims 1 to 4, wherein the upper most of the openings in the sleeves (13) has a chamfered lip for guiding the release plug (16) into the non-flammable sleeve (13). 6. The fitting of one of claims 1 to 5, wherein the non-flammable sleeve (13) has an enlarged outer ring (13a) above an elongated cylindrical portion on an outside wall around the longitudinal axis of the main conduit (11) and wherein a plastic spacer tube (14) is mounted on an inside wall of the main conduit (11) and the elongated cylindrical portion of the sleeve (13) to hold the sleeve (13) in the main conduit (11). 7. The fitting of one of claims 1 to 6 wherein the flammable support (17) is provided by a low melting temperature plastic harness with a strap (17b, 17c) upon which the plug (16) rests. 8. The fitting of claim 7 wherein the harness is attached adjacent to the extension conduit opening. 9. The fitting according to claim 7 or 8 wherein the harness is mounted in an enlarged portion of the extension conduit (12) adjacent to the closure means (18) for the extension conduit opening. 10.The fitting of one of claims 1 to 9 wherein the closure means (18) includes a elastomeric cap secured adjacent to the tension conduit opening by a ring clamp (19). 11. The fitting of one of claims 1 to 10, wherein the second axis (b-b) is at an angle (α) between about 10 and 45 degrees from the first axis (a-a) so that when the first axis (a-a) is vertical the plug (16) will fall by gravity into the main conduit (11) and sleeve (13) from the extension conduit (12) upon release on the flammable support (17). 12. The fitting of one of claims 1 to 11, wherein the main conduit (11) includes a coupling (15) around which cement is poured. 13. The fitting of one of claims 1 to 12, wherein the main conduit includes a coupling (15) which is inserted into a coved opening in the floor (100). 14. The fitting of claims 1 to 13, wherein the main conduit (11) includes a plastic coupling (15) mounted through the floor (100).

Inventors: CORNWALL, KENNETH ROSS
Applicants: CORNWALL, KENNETH ROSS
Application year: 1988
Main classification: E03D1
IPC codes: A62C4, A62C2, A62C3, E03B7, F16L5