WO1999018303A1

WO1999018303A1 - Methods of fireproofing of combustible pipes and conduits

Info

Publication number: WO1999018303A1
Application number: PCT/US1998/020767
Authority: WO
Inventors: Adolf R. Hochstim; Jan Hochstim; Charles R. Eminhizer
Original assignee: Hochstim Adolf R
Priority date: 1997-10-07
Filing date: 1998-10-03
Publication date: 1999-04-15
Also published as: AU1065999A; EP1042567A1; EP1042567A4

Abstract

Disclosed is a fireproofing system for any size of combustible pipe or conduit that passes between and through walls and floors. The entire length of a combustible pipe or conduit (1), on each side of a wall or floor is covered with a fire resistant blanket (4). The blanket consists of a temperature resistant, inorganic, heat insulating layer (4a), which is covered by a fire retardant, heat absorbing material (4b). Larger pipes are additionally covered with intumescent fire retarding materials (4d). Near the wall or the floor, a pipe closing mechanism is to be placed on the top of the blanket (4). The closing mechanism is to be activated by the softening of the combustible pipe from the heat in the event of a fire. Such mechanisms include heat shrinkable materials (8a), weights (14, 14a) and springs (15, 18a) including spring hose clamps (20).

Description

METHODS OF FIREPROOFING OF COMBUSTIBLE PIPES AND CONDUITS

BACKGROUND OF THE INVENTION 1. Field of the Invention

This invention is applicable to a fire-stop system for fireproofing combustible pipes (including conduits, tubings). Those pass from wall to wall, floor to floor and through fire rated walls or floors. The present invention is also applicable to stopping fire propagated along burning combustible pipe and sealing the void in the through penetrations. Thus, the method prevents the passage of flames, smoke and fumes across the wall or floor.

The invention is applicable also to pipes with larger diameter than presently can be fireproofed. The invention does not require restraining collars for intumescent materials to be mounted on walls, floors and ceilings. 2. Discussion of the Prior Art

Combustible pipes are much less costly than metallic pipes, and become in many applications in construction and in industry substitutes for metallic pipes and conduits. In some cases, plastic pipes offer also unique advantage in transporting chemical corrosive gases and liquids, with operating temperatures below softening point of plastic pipes.

However, in a fire, unprotected plastic pipes or plastic conduits burn and the fire, smoke and fumes propagate through the fire rated walls and floors to the other side. Penetrations in the fire rated walls and floors by various penetrants like pipes, cables, etc. need to be sealed with fire tested and certified materials to prevent flames, smoke and gases to reach to the other side. For metallic pipes such approved seals are sufficient. If the pipe is combustible, like plastic pipes then as the temperature of the pipe is increasing the pipe becomes soft, then viscous, then chars and burns. Those plastic pipes are used in closed systems (for process and supply) and in open systems(for drain, waste or vent) . The plastic pipes used in construction industry are made from solid core or cellular type polyvinyl chloride(PVC) and acrylonitrile butadiene styrene(ABS) , polyethylene(PE) , fire retardant polypropylene (FRPP) , chlorinated polyvinyl chloride (CPVC) etc. The property that each type of plastic pipe begins to be soft at temperatures between 90°C( for ABS) to 146°C ( for CPVC)and 148°C (for FRPP), has been extensively used in numerous patents, mostly for PVC pipes, soft at 121°C.

SUBSTITUTE.SHEET(RULE 26) One metho ( "Method 1 " ) proposed using sharp metallic blade ("guillotine"), activated by springs, like in patent 5,331,946, or by gravity, like in patent 3,462,890, or by spring and low melting point metallic alloy, like in patents 4,788,800, 4,449,589), or by intumescent(expanding in heat) material (like in patent 5,257,641).

The difficulty in using those devises are that the shatter plate must be greater than the pipe diameter, and that there may not be enough space for them in practical applications. Furthermore, hot shatters, unless insulated, may conduct heat and cause burning of the pipe on the other side of the wall or floor.

The other method ("Method 2_") proposed to use fire retardant pad, or refractory sleeve inserted in to burned pipe and activated by weight attached to a lever and plate, or pulley (patents 5,301,475, 5,421,127).

Stefely in patents 5,301,475 and 5,421,127 relies on a circular collar, weight, and lever to close ceramic sleeve.

In the open burning pipe close to the wall or floor exler in Patents No. 4,559,745 and 4,796,401 proposed using tension spring squeezable refractory fabric to gain short time for his intumescent material (hydrous sodium silicate)to begin to expand inside his metallic restraining holder.

Another method ( "Method 3_.") uses gates pressing on the pipe, activated by a tension spring(Patents 3,678,634, 3,726,050, 5,253,455). The practical problem is that those mechanical devices may fail due to the corrosion, dirt, etc. after prolonged use in a moist and dirty surrounding. Those devices are also costly. Those devices were not listed as tested in USA by Underwriters Laboratories and are probably not in present use.

Another method( "Method 4_.") with many patents whose ideas are very close to each other(4, 136,707 , 4,559,745, 4,669,759, 4,748,787, 4,796,401, 4,850,385, 4,951,442, 4,894,966, 5,058,341, 5,103,609, 5,132,054, 5,132,054) uses intumescent (expanding in heat) fire-retardant material in a wrap layer, with a various metallic restraining collars.

Intumescent fire-retardant material, bounded by collar on one side, expands in one direction toward the center of the pipe filling the void left by the perimeter burned plastic pipe. With different metallic restraining collars mounted on the walls, floors and ceilings and with different intumescent materials, several such systems are ^ing used now in the construction industry and are, for example listed in Fire Resistance Directory by Underwriters Laboratories. All pipes tested, are only for thickness of pipes with US trade designation : Schedule 40 [e.g. for the outside pipe diameters of 3.5 inches.(89 mm) the thickness is given as 0.216 inch(5.5 mm), for diameter 6.625 inch(168 mm) the thickness is given by 0.28 incϋ(7 mm)]:. The problem with those systems is that as the diameter of pipe increases it requires many more layers of wraps{ (e.g. ,6 layers of wrap strips for a pipe with an outside diameter of 6.6 in (168 mm)} with further increase of the cost of still larger restraining collars. At the present there are no systems applicable for plastic pipe with an outside diameter larger than 10.75 inch(27.31 cm). The other problem is how long such intumescent materials will last. Several years ago, Dow Chemical Company withdrew their material from the market because of their fear that their material, based on a sodium silicate technology , may loose its heat expanding properties with an age. Properties of such materials were reported to be sensitive to the moisture, carbon dioxide and ultraviolet radiation. Lately some companies claim no problem with the aging for their material in this respect, although their material is believed also to be based on sodium silicates. Other intumescent materials currently used(Patent 5,132,054, 5,137,658) are based on expanding graphite with encapsulated liquid isobutane, with two stages of intumescent expansion.

In summary, for the fireproofing of plastic pipes penetrating fire rated walls or floors, all patents examined by us and all systems tested and certified by Underwriters Laboratories and listed in their Fire Resistant Directory of 1997, -are restricted to plastic pipes with an outside diameter of less than 10.75 inches (27.31 cm). In patents most use very ingenious but complicated mechanisms, which have not been accepted in the practice. The only extensively used now are intumescent fire-retardant wraps with restraining steel collars, mounted on the walls or floors.

OBJECT OF THE INVENTION

The object of this invention is to present a completely new system of fireproofing of combustible, nonmetallic pipes passing between walls, between floors and through fire rated walls or floors, which for full coverage are still much less expensive than steel pipes and more durable for normal transport of corrosive chemicals.

Near fire rated walls and floors our new methods are simpler than proposed before and now in use. Our new methods are also applicable to combustible pipes with larger diameters, with thinner and thicker pipes than currently can be fireproofed. Our new method does not require restraining metallic (expensive) collars for intumescent materials.

DETAIL DESCRIPTION OF THE INVENTIONS

Fireproofing of Combustible Pipes and Conduits

If one covers the combustible pipe or conduit only with a thin heat insulating blanket(HIB) , or fabric, made from high temperature resistant inorganic materials(refractory, ceramic and fiberglass) one would only keep inside the closed plastic pipe temperature below burning of plastic materials only for a short time,e.g.,up to 10-20 minutes for 6 mm(0.25 in.) thick refractory blanket(see Table I, last column.

In order to extend the time for the fire protection of combustible pipes or conduits our idea is to use (see FIG. 1) not only heat insulating blanket(HIB) 4a (e.g. , amorphous wool, containing no fibers, for health consideration) and to add to it heat absorbing and fire retarding materials. We will refer to it as fire resisting blanket, FRB, 4_.. For an example, HIB could be spray coated on the inner surface, preferable on on both surfaces, with a thin layer (about 1 mm) of fire retardant, water based, heat absorbing paint, paste, or powder (see claim 16). This type of FRB blanket when subjected to a temperature up to 927°C (1700°F) for one hour, up to 1010°C (1850°F) for two hours and up to 1051°C (1925°F) for three hours, in a standard testing oven, as used in U.S.A. for example by Underwriters Laboratories (UL) , is designed to keep the inside temperature of the pipe below the temperature at which it carbonizes (see Table I)._tFor PVC pipe this temperature is 218°C(450°F) , for CPVC it is 232°C (475°C), (see Table I). Those temperatures are slightly higher than those called T hourly rating, used in U.S.A., which are 181°C(325°F) above ambient temperature, i.e., about 200°C(400°C) for 1,2,3 and 4 hours.

Fire resistant blanket(FRB) 4_. should be slightly loose to allow for small contraction of blanket material in the heat(e.g. 2 to 5%) and should be covered with thin sheet of protective weather cover ,1c, e.g. , by layer of fiberglass or aluminum or stainless steel foil.. In covering large pipes about 1 inch (2.54 cm) in width should be added for the overlap for large pipes. The FRB can be secured to the combustible pipe for an example with a stainless steel hose band clamps, ∑, or using 0.75 in. (19 mm) wide fiberglass filament tape and steel tie wire.

FRB can also incorporate existing fire retardant intumescent material 4d,4e, which could be a paint- like material, it should expand about 30 to 50 times by volume at approximately 140°C (248°F) and prefarable chemically binds the nitrogen-oxide and chlorine decomposition products released by PVC during its pyrolization, Thus, besides its fireproofing ability, such materials also suppresses the generation of toxic products usually formed during combustion of PVC. Second layer of HTB can be added under the insulating layer as shown in FIG.l. Another type of intumescent fire retardant material _.4d which exists and be used in FRB, specially inside wall or floor, when exposed to the temperature of 300°C (572°F) creates a voluminous foam through a carbonization reaction. This foam is fire resistant and a good heat insulator. The foaming increases volume several times.

Region I. Fireproofing of Entire Length of Combustible Pipes and Conduits Presently used ceramic blanket, like 3M Fire Master™(see Table I) cover plastic pipes and conduits and require for 1-2 hours fire protection thickness of 1-3 inches( 3.5-7.5 cm). The fire protection is the passing of fire test in UL, or in a similar furnace, according to the time-temperatures specification given by ASTMS(UL263) . For details see Appendix A. For the same ceramic blanket with thickness of 0.5 inch(1.8 cm) the flame spread along the longitudinal dimension of plastic pipe according to the test specified by UL 910(NFPA 262) was 1.4 ft(42 cm) in 20 minutes. Because FRB has additional properties, like heat absorption, much thinner, thus more flexible and therefore easily squeezable blanket can offer better and longer fire protection. For extra safety we are proposing special firestops, located at different distances from each other, along the length of plastic pipe, covered with FRB(see FIG.12). The firestop are to consist, for example, from the following: steel clamp, then underneath in the following order: FRB, heat shrinking wrap, intumescent fire retardant wrap on the top of plastic pipe or conduit. The other simpler option is to use steel clamp, FRB and intumescent wrap. This method can be used fort large plastic pipes.

Region II. Sealing Through Penetrations

The entire void(see 2 in FIG.2) inside fire rated walls or floors (e.g., made from concrete or fire rated gypsum panels) should be sealed around the fire resistant blanket, FRB, with tested and approved seals (see UL Directory) , (see 5_ in FIG. 3). For an example the seal can be rigid, cementitious, heat absorbing material, which absorbs heat and expands on curing making tight fit. It should be waterproof_^ The seal so installed (see 5_. in FIG 3) will prevent flames, heat, smoke and gases to pass to the other side of the wall or floor and will be resistant to over- pressure caused by the fire and water pressure from the fireman's hose.

The fire system of covering the combustible pipe, or conduit, in Region I and Region II offers complete fire protection to combustible pipes, for a continues operation (e.g. ,for up to 3 hours in fire) of any diameter, any thickness and any composition of combustible pipes.

For an extra safety, inside penetrations in walls and floors , one can place intumescent fire retardant wrap between pipe and FRB inside the penetration ( see Method I) .

If one considers pipes or walls (floors) movements, or an extra heat insulation, then the FRB blanket on each side of the wall or floor can be mounted to the floor or wall with a metallic anchor rings (see 6 in FIG.4 ) fastened to the floor or wall. The blanket either continuos on or stops as in FIG. 4.

Region IA. Near Wall or Floor. Sealing- of Burning Plastic Pipes with Squeezed FRB

The fire protection offered in Regions I and II, for entire length of combustible pipes is cheaper than using metallic pipes, but may be not practical in two cases: a. if the of cost of FRB is higher than two known closing devises, b. if in the case of fire there a is concern for a particular situation, that on the fire side some mechanical object falling on the pipe may break the pipe. The last concern can be avoided by providing closing mechanisms near the walls, or floors (see FIGS.6-11, 13-16) , or in addition in several locations in Region (see FIG.12) for an extra safety for fully covered pipe.

Various ways of closing the heat softened pipe to flames and gases were proposed and were reviewed by us in the Discussion of the Prior Art. Most were either to complicated for practical use, and those currently in use are for pipes with an outside diameter less than 10.75 in( 27.3 cm).

Basically, one can squeeze(pinch) the FRB and the heat softened pipe by either applying uniform pressure around- forming a reduced cylinder(tube) , or by applying horizontal pressure to a two flat plates, like squeezing FRB and the plastic materials into a "sandwich". One can show mathematically that the second method is more effective in tightly packing the materials together and requires less force. If FRB is to thick, one can use thinner FRB near closing device merging with thicker FRB, and / or squeeze pipe in front of the FRB.

When fire will propagate along the pipe it will encounter the compressed small tube or a "sandwich", both with interwoven plastic material with FRB, and thus encounter heat insulating, heat absorbing, intumescent, fire retardant materials. This almost solid core block, will char, generate smoke and will prevent, or significantly reduce, further spread of fire inside FRB.

In Methods A-I we are proposing several new ideas for closing the FRB blanket, covering the heat softened plastic pipes, which are also applicable to larger than 10.75 in (27.3 cm) pipes-the currently largest plastic pipe which can be fireproof using collars and intumescent wraps.

Method A. Use of Heat Shrinking Material for Closing FRB Around Combustible Pipes (Squeezing into a Smaller Tube)

Certain organic molecules, like polyolefin, after special treatment of induced elastic stretching, shrink 2-5 times, when exposed to the heat in the range of 125-130°C, which is the range of softening of plastic pipes ( 90-l48°C) (Table 1A) . Several companies are making such materials for sealing torn insulation on an electrical cable with a torch. One heat shrinking material MBSM is made by Raychem Corporation. When it is wrapped around cable and then exposed to the heat it shrinks 5 times in the circumference (thus also in the diameter). It is heat shrinkable, wraparound sleeve, consisting of reinforced fabric contained in a polymer matrix material. The wrap 8a from Raychem has insertible metal channel strips 8c to butt the flexible sheet of wrap together( see FIG.5). It occurred to us that placing small band of such heat shrink wrap around the fire resistant blanket, FRB, which in turn covers the thermo-plastic pipe(see 8a in FIGS.5, 6, 7 and 8), when exposed to the heat it will shrink, closing(cinching) the blanket around the heat softened pipe to a smaller diameter tube. As can be seen from Tables I for a typical furnace, like UL, with the increasing temperature first ABS pipe will soften at the temperature of 90°C, then PVC, PE, PEX at 121°C, then heat shrinking material MBSM will begin to shrink from 125 to 130°C. The CPVC and FRPE pipes will become soft at the temperature of 146-148°C. The fire simulated in the standard oven should reach 125 °C in about 8 seconds and the thin MBSM should reach that temperature at the same time is expected to complete shrinking before T=150°C,i.e, in about 10 seconds.

For pipes with an outside diameter equal or smaller than 10 inches (25.4 cm), the HSM type to be used is such that it should shrink by a factor of 2-3. Raychem is making such HSM, with trade name of CPSM, also from radiation cross-linked polyolefin, as a wrap or as a tube. After squeezing FRB, the fire along the pipe will then encounter inside plastic pipe soft plastic material surrounded by FRB ( see FIG.6a). For comparison in flattening FRB and pipe ( to be discuused later) the fire will encounter different situation (see FIG.7).

For pipes having an outside diameter greater than 10 inch(25.4 cm), we are proposing in addition to cover the plastic pipe with a layer of intumescent fire retarding strip, or paint or incorporate it in FRB(see 4d,4e) and then covering it with FRB . Upon heating HSM will squeeze the FRB around the soften pipe into an almost solid core.

For rapid onset of fires, like in oil, or pit fires( e.g., reaching 1000°C in 5 minutes, see UL 1709 High Intensity Fire Test) the use of slightly fireproofed HSM will allow HSM to shrink, before is burned. One can place on the top of heat shrink material (HSM) , a thin layer of insulation. Such fireproofed HSM will have a delaying in time shrinkage. After HSM will tightly squeeze FRB and the softened plastic pipe, and if HSM will continue to shrink and squeeze further FRB, HSM may break or split at the joint, so that HSM in form of a tube may be preferable.

A variation is to place FRB 4_. on the outside (see FIG.8) with intumescent fire retardant 9a on the top of HSM 8a,, which is on the top another layer of FRB (not shown in FIG.8) and on the top of plastic pipre 1 . The HSM will shrink squeezing FRB and may burn among intumescent material .

Method B. Using Cord with Weight or Retractive Spring to Close FRB(Squeezing in to Smaller Tube)

A steel cable is passed on the top of FRB (on top of combustible pipe), preferably inside of cylindrical tube made from high temperature resistant ceramic material (see FIG.9, 10). Weight 14_. is attached on one or both ends to a rope or cable ,or rope or cable is attached to retractive spring(FIG.lOb) .

Method C. Use of Various Springs to Close FRB Around Combustible Pipe(Squeezing to a Smaller Tube)

A direct use of stretched springs may damage FRB, therefore we recommend covered following springs. a. Use of "heat shrinkable belt", made from one or several stretched springs. When in stretched position those springs are submerged into a low melting point, molten plastic material. When cooled off the stretched springs .will be inside flexible "heat shrinkage belt" . Such belt is to be placed on FRB, instead of HSM (see A) b.Use of several springs (see FIG. 14).

Method D. Use of Weights to Close FRB

(Squeezing FRB and Plastic Pipe into a Flat "Sandwich") The flat "sandwich" configuration is more efficient means of constricting FRB and plastic material.

Use of moderately heavy steel chain (see FIG. 11) fixed to the floor or to a horizontal steel plate mounted to the wall. The chain 14a passes over FRB. As the combustible pipe becomes soft in the heat the chain will close the FRB.

Instead of springs in FIG.13, one can use heavy upper movable plate as weight(see FiG.13a).

Method E.Use of Various Springs to Close FRB Around Combustible Pipes (Squeezing to Flaf'Sandwich" ) a. Use of several(e.g. , four)_springs between two parallel, movable steel plates (see FIG.13). b. Use of "heat shrinkable spring belt", for application C.a. above, on the sides of two parallel moving plates

(see FIG.13c). Those are stretched springs immers in a molten plastic, which upon cooling are flexible. When heated, plastic will melt and those heat resistant springs_will be activated.

Method F. Folding, Bending Heat Soften Pipe with FRB. FRB blanket can be closed when pipe is soft from the heat by bending the pipe and FRB in upward pr to the side position. The analogy is lifting n <i£3tι covered -with a robe and observing closure at the elbow position. The closure can be made, for an example, by two springs. We had good result by fasting two spings at the same place one one steel clamp and similarily on the other side of the pipe to the same place on a second steel clamp.

Method G. Temperature Activated Closure Device Two flexible closure bars are permanently bend at each other end, the ends of left bar are bent to the left and the ends of the right bar are bent to the right. At one end of each bar is attached a hinged clip. When the ends of the bars are brought together, the clip secures them and the hinged flap of the clip extends down the side of the bar not having the a clip attached. The hinged flap is held in place by a bend made from a material which melts at a temperature where pipe will be softened. The bars then will squeez FRB and plastic pipe.

Method H. Use Of Intumescent Wraps Inside Walls and Floors With or Without Squeezing FRB

For small closed pipes, with outside diameter up to 2.4 in(6cm) some companies (see UL Directory) used their intumescent materials inside walls and floors, without any restraining collars or seals. For larger pipes we are proposing to enlarge the annular space near each side of the wall and floor in order to :(i) to place on the top of combustible pipe or conduit enough thicknes( depending on the pipe's or conduit's diameter) of intumescent fire retardant material, (ii)covere it with FRB blanket and (ii) sealing the space touching wall's or floor's material -for the required depth and thickness with fire rated rigid seal.

Method I. Use of Spring Hose Clamp to Squeeze FRB and the Plastic Pipe The hose spring is made from a heat induced elastic metal, which works like a spring or like a heat shrink(see Method A). It can be used on top of FRB which is on the top of plastic pipe, or on a thin layer of ceramic ahead of layer of FRB. Upon heating, the plastic pipe becomes soft and can be squeezed. Various options discussed in Method A with heat shrink material HSM apply also with the use of hose sping under a tension..

The time-temperature of the standard testing furnace, simulating typical fire, follows in U.S.A. American Society of Testing Materials, Standard ASTM E119, which is the same as UL Standard 263 by Underwriters Laboratories. The international Standard ISO 834 is very similar. Table I shows temperatures for various times in the ISO furnace, and the time when various plastic pipes will become soft, viscous, carbonize and ignite. As can be seen from Table I there are about 2 minutes to close the pipe. If the plastic pipe is well insulated, like in our invention, then one needs delaying time to allow pipe to soften and to increase the heat flow to the area of the pipe being constricted. If the pipe, in front of FRB, is covered with a thin layer of refractory material and then squeezed with a spring clamp or heat shrink HSN, this will delay the fire inside the pipe and allow the pipe under FRB to soften. TABLE I. TEMPERATURES FOR DIFFERENT TIMES IN AN OVEN AND PROPERTIES OF THERMO PLASTICS

COMPUTED***

ISO CORRESPONDING

OVEN TEMPERATURES,°C

TEMPERATURES * BEHIND CERAMIC BLANKET AND PAPER

TIME TEMPERATURE

PROPERTIES OF** KAOWOOL SF607

THERMO PLASTICS BLANKET PAPER BLK t,sec T,°C ABS PVC CPVC 0.25in. 0.25in.lin.

FRPP (6mm) (6mm) (25mm)

4 90 ABC: softens

7 121 PVC: softens

8 125

9 135

10 146 FRPP,CPVC: softens

14 177 PVC:viscous

18 202 CPVC:viscous

21 218 PVC: carbonizes

23 232 CPVC; carbonizes

75 380 FRPP: flash ignition

82 391 PVC: flash ignition

2.0 mm_ 443 CPVC: flash ignition

2.1 min 454 PVC: sustained ignition

2.2 mm 466 ABS: sustained ignition

3 min 502

6 600 90 80 75

10 min 678 200 150 131

15 min 738 370 300 159

30 841 650 540 190 lh 945

2h 1049 244

3h 1110 268

* The oven temperatures were obtained from ISO's equation:

T(°C)=149.8 ln(0.1333 t_sec +l)+20

** Properties of thermoplastic materials were obtained from manufacturers

*** Time depended heat transfer calculation, courtesy of Thermal Ceramics . TABLE II. SUMMARY OF NEW METHODS FOR FIREPROOFING OF COMBUSTIBLE PIPES AND CONDUITS

FRB-flexible, high temperature resistant, heat insulating blanket, coated with fire retardant, heat absorbing paste or paint and sometimes with a layer of intumescent material

HSM-heat shrink wrap (e.g. radiation cross-linked polyolefin)

REGION I REGION IA REGION II all space between space near the void space inside wall to wall or fire rated wall or fire rated wall or floor to floor floor floor around the pipe see FIG. 2 see FIG.2 (see 3_. in FIG.2)

1. cover pipe with FRB 1. covering with 1. lacing FRB

(claim l,6)FIG.l FRB(see 4_. in around the pipe 2. special firestops FIGS.3-etc. ) and sealing with

(claim 12 ), FIG.12 (claim 2 ) standard fire stop 5. 3. heat absorbing 2. closing pipe FIG.4a or powder in FRB with: mounting FRB 4 on (clasim 5_,6_. a. HSM see 8a, FIGS. wall or floor (see 5, 6, 8, 12a, 15) FIGS.4b, c) (claim 3 )

(claim 1, 8 , 9_.) b.rope and weight 2.placing intumescent FIG.9, 12) fire retardant wraps ( claim 11a) inside enlarged c.rope and spring annular space on FIG.10(claim lie) top of pipe or d. chain and steel plate conduit, with

FIG.lKclaim lib) FRB and rigid e. springs and steel plate seal (claim 4)

FIGS.13a.b(claim lid) f.weight and steel plate

FIG.13c.d(claim 7b) g. temperature activated closure device (claim lie) h. ending method

FIG.14(claim llf) i. spring hose clamp20(claim llg)FIG.15 3. cover pipe with HSM 8a intumescent fire retardant 9a and FRB (claim 8 FIGS.8 4.heat insulated HSM

( claim 11a) 5. intumescent fire retardant between 9a, HSM 8a and FRB 4(claim 13) 6. on pipe in front of FRB 4_.: ceramic 4aι, HSM or spring hose clamp 20. (see FIG.15) (claim 14) LIST OF FIGURES

FIG.l Cross section of fire resistant blanket (FRB) 4..

4a-fire resistant, heat insulating, inorganic blanket

(HIB). Optional-second HTB under 4c , as shown. 4b-fire retardant, heat absorbing paste, paint, etc. 4c-weather proofing, e.g., thin layer of fiberglass, or aluminum and stainless steel foil. d- (optional) intumescent fire retardant. Specially to be used inside walls or floors 4e-(optional) intumescent coating removing chlorine compounds from burning PVC or CPVC. FIG.2 Combustible pipe(or conduit) 1 passes between walls or floors 2 ( Region I), inside of fire rated walls or floors 3. (Region II).

Region I, close to the wall or floor is referred as Region IA. FIG.3 Combustible pipe (or conduit)!, covered along entire length with fire resistant blanket A (FRB-see FIG.2) and penetrations inside wall or floor are sealed with fire seal 5 ) . FIG.4. Use of FRB 4: near wall or floor and the fire seal 5 . FIG.4a, 4b Method of attaching FRB 4_. to the wall and floor, for extra protection agaάnst movements. FIG.5a, 5b, 5c Inmstallation of Heat Shrink Material MBSM, 8a. FIG.5a MBSM stretched out as a sheet with 2 rails 8d FIG.5b MBSM wrap folded around the pipe with the sliding steel channel strip 8c. FIG.5c MBSM wrap δa_^completed around the pipe with FRB. FIG.6a, Use of heat shrink material (HSM) a, or other squeezable device on the top of fire resistant blanket (FRB) 4_., on the top of combustible pipe 1 . FOG.6b Exposed to the heat, 2a will shrink to 8b , the pipe with original diameter D will shrink to d. The circle with AB indicates the cross section of the pipe at points AB. The softened by heat plastic material ib_occupies one of possible forms. FIG.7 Cross-section of flatened pipe with FRB between parallel plates. Fire is on the left. FIG.8a The same as in Fig.6, except the fire resistant blanket(FRB) 4_. is on the outside. The plastic pipe is being squeezed by HSM preventing fire and heat from below and above the pipe. Extra intumescent material 9b fills the space between the pipe and FRB. FIG. 8b. The same as FIG.8a after epansion. FIG.9a FRB closing mechanisms: (cord attached to structure- not shown) : weight JL4. pulling on cord ϋ on a horizontal pipe. FIG.9b The same on vertical pipe, by placing horizontal pipe covered with FRB. FIG.9c. Use of steel rope H inside of fire resistant, flexible tube to which is attached weight 14. FIG.10 The same as in FIG.9c, but the rope is attached to a retractive spring 15. FIG.11a Weights 14 attached to a steel cord , or weighted heavy chain 14a is fastened to a horizontal steel plate 12, mounted on each side of the wall 2 . FIG. lib The same as in FIG.11a, different view. FIG. lie Heavy chain 14a is mounted to the floor 2a or to a steel plate 16. FIG.12a Examples of special fire stops for the entire length of plastic pipe (Region I and la) for a complete pipe's coverage with FRB. FIG.12b The crossection for FIG. 12a. FIG.13a Springs 12 are attached on the bolt 21 to two parallel steel plates ( with upper plate moving). FIG.13b Close view of the bold 1 and spring 18.

FIG.13 c. Heavy plate sliding down when plastic softens.

FIG.13d. Close view of the bolt 2! and the srew 17.

FIG.14 Bending FRB and the soften from the heat plastic pipe by means of two heat resistant springs 12 and two steel clamps 2. Only one possible way is shown.

FIG.15 Use of hose clamp under tension 22 or HSM 8a for first closing plastic pipe, covered with thin HSM 4a,, in front of FRB 4., to be closed later by other means. LIST OF REFERENCE NUMERALS IN FIGURES

1 combustible pipe(or conduit) la squeezed softened by heat pipe 1 lb charring pipe's material 2_. fire rated wall or floor 2a fire rated floor 2b fire rated ceiling void inside of wall or floor

4. fire resistant blanket(FRB)

4a inorganic high temperature resistant, heat insulating layer

4b fire retardant, heat absorbing paste or paint

4c thin insulation layer(e.g., fiberglass, or aluminum and stainless steel foil. 4d (optional) intumescent fire retarding layer(same as 9a) . 4e (optional) intumescent fire retardant layer, removing chlorine in burning CPV or CPVC pipe.

5. penetration fire stop seal in void

6 steel anchor ring with FRB mounted on the wall or floor

2 stainless steel band clamp

8a heat shrink material (HSM) , before shrinking

8b heat shrink material(HSM) , after shrinking

8c metal channel strip to butt wrap

8d rail

8e burning HSM material

9a intumescent strip, before expansion(same as 4d) .

9b intumescent strip, after expansion

10 slightly heat insulated heat shrink material high temperature resistant ceramic or stainless steel rope high temperature resistant ceramic tube restraining chain weight a weighted chain recoilable, retractive heat resistant spring steel plate a heavy steel plate(e.g., or steel plate with concrete) screw heat resistant spring a heat resistant spring(s) stretched out inside " heat shrinkable belt"inside flexible plastic mold b relaxed spring, without plastic mold plastic mold σsβ÷ damp' under tension teel bolt

Claims

Claims: We Claim:

1. Fire protection of a combustible pipe by covering it on the outside with a fire resistant blanket (FRB) consisting of at least one layer selected from the group consisting of: (i) a layer of high temperature resistant heat insulating material, (ii) a layer of fire retardant, heat absorbing materials, (iii) an intumescent fire retardant layer, and (iv) a thin, weather insulating, light reflecting layer.

2. Fire protection of combustible pipe penetrating a fire rated structures, by covering it with squeezable fire resistant blanket(FRB) , claimed in claim 1 , that extends through the fire rated structure and protrudes on each side of the structure for a distance of approximately the diameter of the pipe.

3. Fire protection according to claim 2 , with moveable combustible pipes and conduits, wherein the fire resistant blanket FRB, as claimed in claim 1, is mounted on each side of fire rated structure with a steel anchor ring and a stainless steel band clamp.

4. Fire protection according to claim 2 , of a combustible pipe inside a fire rated structure with the addition of:

(i)an intumescent fire retardant material, (ii)the FRB, claimed in claim 1, and covered by a (iii) fire rated seal, preferably a rigid one that expands during curing.

5. Fire protection using FRB blanket, claimed in claim 1, with the further addition of a heat absorbing powder which can be made from an inorganic, cementitious mixture of minerals used as a fire seal, with an added water, cured, and powderized again.

6. FRB blanket, as claimed in claim 1 and with an addition of powder claimed in claim 2 can be used in other applications, like for fire protection of steel beams, steel columns, aluminum pipes, etc.

7. Fire protection of the inside of combustible pipe in the application claimed in claim 2 , comprising of a heat shrink tube HSM, placed on the top of FRB, claimed in claim_J,, which is on the top of a combustible pipe, which softens at elevated temperatures, at which HSM shrinks, closing the plastic pipe.

8. Fire protection according to claim Z, further comprising of the FRB , with intumescent fire retardant material, as claimed in claim l,(iii), placed over HSM, which is to be on the top of a thin layer claimed in claim l,(i), which covers the combustible pipe.

9. Fire protection of combustible pipes, as claimed in claim 2, for rapidly starting fires, in order to delay burning of the HSM by covering it with at least the following materials: (a) heat insulation and (b)an intumescent fire retardant.

10. Fire protection according to claim 2 for means of various mechanical closing devises over FRB, claimed in claim 1 , which closes as the pipe is softened by heating.

11. Fire protection according to claim 12, wherein the means for closing pipe comprise of at least one element selected from the group consisting of: (a)weight attached to high te erature resisant rope; (b) weights attached to steel cord, fixed to a steel plate, mounted to the structure;

(c) high temperature resistant rope with retracting spring;

(d) stainless steel, heat resistant springs between two parallel stainless steel plates mounted to a fire rated structure;

(e) automatic device using a lateral pressure applied on opposite sides of the pipe by two pre-flexed closure bars, by using bars bent at each end and clamping the two bars together at their ends with low melting point material for the activation;

(f) bending FRB and plastic pipe by means of a stainless steel spings, preferable covered with ceramic tube;

(g) stainless steel tension spring.

12. Fire protection according to claim 1, further comprising placing fire stops in a several locations along a length of FRB.

13. Fire protection according to claim 1 , further comprising placing underneath the FRB, a layer of intumescent material, then heat shrink material (HSM) on the top of another FRB, on top of the plastic pipe,

14. Fire protection according to claim 12, for improving heat flow to speed up the softening of the combustible pipe under the FRB, by means of : ( i) covering the pipe, in front of FRB with a thinner version of the FRB, (ii) placing heat conductor on the pipe, leading directly to a thin metallic bands on the pipe, where the main closing devise is located, and (iii) placing heat releasing chemicals underneath the metallic bands, permitting at the same time closing FRB and pipe on both sides of the structure.