Insert block half, and a sealing system comprising said insert block half

The claimed invention relates to an insert block half, and a sealing system comprising said insert block half.

Background of the invention

Sealing systems for cables and pipes are required in several different applications, for example in ships, offshore industry and buildings, in case of accidents like a fire, an explosion or leaking liquids. The sealing system is used for protecting important components and areas, and to delay the spread of fire or a leaking liquid within for example a ship, a building, a vessel or oil platform. Sealing systems for cables and pipes are therefore frequently used in several applications in order to seal cable and pipe transits.

In order to reduce the overall weight of ships, offshore platforms and buildings etc. previously used metal pipes are replaced by pipes made of a plastic material. These plastic pipes are also easier to install, which reduces the overall cost for the installation.

Plastic pipes are however not as resistant to fire and heat as metal pipes. The use of plastic pipes therefore requires different types of sealing systems for transits through partition walls in order to avoid that fire is spread via the pipe transits through partition walls etc. and to stop leaking fluids from passing through the remaining opening when the pipe has burnt off.

Previously used sealing system for pipes comprises a cylindrical tube shaped frame secured in the partition wall. The diameter of the frame is selected from the diameter of the plastic pipe that should be lead through the partition wall. The frame diameter must be big enough to make room for a cylindrically shaped sealing device fitted around the pipe within the frame. Each sealing device consist of two pressure sealing rings placed close to the ends of the cylindrical tube shaped frame and an intermediate ring of an

intumescent material. Each sealing ring comprises an elastic ring and at least two screws passing through the elastic ring in axial direction of the ring. Each screw is provided with a tensioning arrangement so that the screw, when tensioned, compresses the elastic ring in axial direction and thereby forcing the elastic ring to expand in radial direction both inwards and outwards to seal the pipe transit.

The intumescent material will, when the critical temperature for the specific material in use is reached, expand considerably and seal the entire space within the frame to thereby avoid that the fire or water is spread to the opposite side of the partition wall.

Intumescent materials are frequently used in fire protecting devices since the increased volume when a specific temperature is reached is used for sealing different passages or gaps when a critical temperature is reached.

The known sealing system for plastic pipes does however suffer from several draw- backs. The first one is that only one pipe is allowed to pass through each frame. Different areas where sealing systems are required do however include several pipes in different sizes, which consequently result in that a number of frames in different sizes must be installed in the partition walls. This is costly, and if some pipes must be replaced the diameter must remain the same to fit within the already installed frame. Secondly, another drawback is that the overall axial length of the sealing system is long since it includes two pressure sealing rings and an intermediate ring of an intumescent material. The fact that the intumescent material is placed in the middle of the two sealing ring does also have a negative impact on when the expansion of the intumescent material is activated, since the sealing rings will protect the intermediate in- tumescent ring from the heat and therefore delay the activation of the intumescent material. In the end, the delay increases the risk that fire is spreading to other areas via the passage.

A more flexible and quicker reacting sealing system is consequently desired.

Summary of the invention

The claimed invention provides a sealing system that reduces the above described drawbacks, and provides a more flexible sealing system. This is achieved by using a device and system as defined in the characterising portions of the independent claims.

Sealing systems used today for cables and metal pipes lead through partition walls comprises a metal frame secured in a partition wall. Each pipe or cable passing through the frame is surrounded by a rectangular parallelepipedic insert block, normally made of two identically shaped insert block halves. Each insert block half is provided with a half cylindrical groove with a diameter that matches the diameter of the pipe or cable so that the two sections fit around the pipe or cable when put together. The pipe and the insert block are stored within a rectangular or tube shaped frame. If the frame comprises more than one insert block a metallic plate, provided with protruding flanges that keeps the insert blocks in the right transverse position within the frame, is placed between each layer of insert blocks within the frame in order to secure each layer in the frame. If the frame is rectangular is at least one pressure sealing means placed somewhere within the frame, and if the frame is tube shaped the sealing means are provided around the at least one insert block within the tube shaped frame. The pressure sealing means are, when tensioned, applying a pressure on the in- sert block or blocks within the frame so that gaps between the different components within the frame are sealed. The size of the insert blocks are selected to fill the interior width of the frame completely when packed side by side and the size of the groove is selected to provide a tight fitting around the pipe or cable extending through the insert block.

The claimed invention is characterised in that the rectangular parallelepipedic insert block comprises two insert block halves, and that at least one of the insert block halves has a section consisting of an intumescent material, which expand at a predetermined temperature.

The claimed invention is usable in existing cable and pipe transit systems already installed in different partition walls. This is an advantage since the existing frames are usable for the new plastic pipes when the existing metal pluming is replaced or modified. If the pipe or pipes are destroyed by fire the intumescent material will, when the critical temperature is reached, expand and close the opening in the insert block to prevent that fire is spread to the opposite side of the partition wall. The possibility of using already installed sealing systems reduces the cost considerably since both the time for installation and the cost form material is reduced.

The volume of the intumescent material increases considerably (about 20 times its original volume) when the critical temperature is reached.

If only one insert block half is of the above described type the other one will be a conventional insert block half made entirely of elastic sealing material.

The claimed invention is further characterised in that the insert block half comprises a centre portion and two outer portions placed on both sides of the centre portion in the axial direction of the groove. The centre portion is made of an elastic sealing material and the two outer portions are made of the intumescent material. This embodiment of the invention has the advantage that the portions comprising the intumescent material will be positioned towards the area where the fire, and consequently also the heat is. The intumescent material will therefore be exposed to the critical temperature earlier, and close the passage in the partition wall earlier. The risk that the fire is spread further compared to the already existing devices, where the intumescent material is placed between the sealing devices, is therefore reduced considerably.

Yet another favourable embodiment of the claimed invention is characterised in that all sides, except the side provided with the groove and the groove, are surrounded by a cover having the same shape as the insert block half, except that the sides placed adja- cent to the side provided with the groove are slightly shorter than the corresponding side of the insert block half. The cover ensures that the expanding intumescent material

inside the cover is expanding in the direction where the passage through the insert block is. The shorter sides of the cover are necessary to make sure that the elastic sealing portions on the two insert block halves are in contact with each other. This embodiment ensures that the passage will be closed as quickly as possible.

If the radius of the of the groove is large in relation to the size of the insert block half, the length of the insert block half in the axial direction of the groove could be increased so that the outer sections could include a larger volume of intumescent material. The increased volume of the intumescent material ensures that the passage for the pipe will be sealed completely.

Another favourable embodiment of the invention is characterised in that the cover on the three sides arranged in planes parallel to the axial direction of the groove is provided with a slot transverse to the axial direction of the groove so that the centre por- tion is uncovered. The slot ensures that a sufficient pressure is applied to the elastic central portion to seal the transit.

The cover is preferably made of a not thermally insulating material, preferably a metallic material, to ensure that the expansion of the intumescent material not is delayed.

In one preferred embodiment of the invention is each of the outer portions consisting of at least two different layers of intumescent material.

Each insert block in the pipe transit comprises two insert block halves placed together with their substantially semicircular grooves together so that a substantially circular passage through the insert block is generated. At least one, but preferably both, of the two insert block halves is an insert block half comprising intumescent material as described above.

The invention is used in a sealing system for at least one plastic pipe passing through a partition wall. The system comprises a frame secured in the partition wall, at least one

insert block as described above and pressure applying means for sealing said system. The insert block is fitted around the plastic pipe and placed within said frame together with the pressure applying means that, when tensioned, seals said system.

Brief description of the drawings

The claimed invention is described in detail with reference to the attached drawings illustrating:

Figure 1 Illustrates a schematic view of a prior art sealing system for pipes and cables. Figure 2 Illustrates a perspective view of one embodiment of an insert block half according to the present invention.

Figure 3 Illustrates a sectional perspective view of a rectangular seal- ing system comprising one embodiment of the present invention. Figure 4 Illustrates a sectional perspective view of a tubular sealing system comprising one embodiment of the present invention.

Detailed description

A conventional sealing system 10, illustrated in figure 1, comprises a frame 11 secured in a not illustrated partition wall. The size of the frame 11 is selected from the number of cables and/or pipes that has to be lead through the wall. Cables and/or pipes are lead through the frame 11 via rectangular parallelepipedic insert blocks 12 fitted around the cables and/or pipes and stored within the frame 11. The shape and size of the blocks is selected so that they fill the width of the frame 11 completely. Each insert block comprises to substantially identically insert block halves 15 made of an elastic sealing material resistant to pressure, liquids and heat. If the number of cables or pipes not is enough to fill the space within frame, blind insert blocks 13 without an opening are used to ensure that the space within the frame 11 is filled completely. Between every

layer of insert blocks is a plate 16 provided in order to maintain the insert blocks in the intended position within the frame 11. Somewhere within the frame 11 is a pressure applying device 14 arranged. The pressure applying device 14 does, when the screws 15 are tensioned, expand which results in a pressure applied on the insert blocks 12 and 13 within the frame 11. The pressure applied on the insert blocks 12 and 13 seals the cable transit.

One embodiment of the claimed insert block half 20 is illustrated in figure 2. The insert block half is shaped as a substantially rectangular parallelepiped provided with a substantially semicircular groove 21 extending along one of the sides of the block half 20. The axial direction of the groove 21 is substantially parallel to the edges of the block half 20. The insert block half 20 comprises a centre portion 22 and two outer portions 23 placed on both sides of the centre portion 22 in the axial direction of the groove 21. The centre portion 22 is made of an elastic sealing material and the two outer portions 23 are made of intumescent material. All sides of the insert block half 20, except the side provided with the groove 21 and the surface of the groove 21, are surrounded by a cover 24. The cover 24 has substantially the same shape as the insert block half 20, except that the sides placed adjacent to the side provided with the groove 21 are slightly shorter than the corresponding side of the insert block half 21 in order to ensure that, when two insert block halves are fitted around a plastic pipe, the elastic central portions 22 on the insert block halves will be in contact with each other and seal the pipe transit when the pressure applying device is applying a pressure on the insert block halves 20 In order to further ensure that the pipe transit is sealed properly is the cover 24 on the three sides arranged in planes parallel to the axial direction of the groove 21 provided with a slot 25 transverse to the axial direction of the groove 21 so that the centre portion 22 is uncovered. The slot 25 guarantees that pressure will be applied on the central portion 22. In order to not delay the expansion of the intumescent material is the cover 24 made of a not thermally insulating material, preferably a metallic material. . The cover 24 is used both for keeping the intumescent mate- rial in the right position in relation to the central portion 22 and directing the expansion of the intumescent material towards the groove 21, and thereby sealing the groove

21 if the pipe is burning. Both ends, in axial direction of the groove 21, of the illustrated insert block half 20 are tapered starting from the two edges 26 on the three outside surfaces of the block half 20. The length of existing insert block halves, consisting entirely of elastic sealing material, used in already installed is equal to the length be- tween the two edges 26 on the insert block half 20. In order to make the claimed insert block half fit within existing sealing systems must the length of the insert block half be equal to the length of the insert block used today or provided with tapered ends to make room for the plate 16 separating each layer of insert blocks within a frame 11. The preferred illustrated insert block half embodiment has the advantage that since the length of the insert block half is increased compared to existing elastic insert block half the size of the two outer portion 23 could be increased which makes it possible to incorporate more intumescent material into the two outer portions 23 and further improve the sealing of the groove 21.

Figure 3 and 4 illustrates the claimed invention used in two different types of frames, one rectangular and one tube shaped frame. In order to illustrate the interior of each sealing system are some parts removed.

The rectangular sealing system 30 comprises a frame 31 secured in a not illustrated partition wall, three layers 32, 33, 34 of insert bocks separated by plates 35 and a pressure applying device 36. The sealing system 30 is arranged to provide transit for four pipes 37, only two illustrated in the drawing. Insert blocks consisting of two insert block halves 20 according to the claimed invention are fitted around the pipes 37 and placed within the frame 31. The pipes 37 and the insert blocks fitted around the pipes 37 does however not fill the entire frame 31 and the remaining space are filled with blind insert blocks 38 having the same size as the claimed insert blocks. When all pipes 37, insert blocks, blind insert blocks 38 and separating plates 35 are in the intended position within the frame is the pressure applying device 36 positioned within the frame 31. The pressure applying device 36 is provided with screws 39 which, when tensioned, makes the device 36 apply a pressure on the different parts within the frame 31 and seal the pipe transit.

The tubular sealing system 40 comprises a tube shaped frame 41 secured in a not illustrated partition wall, one insert block a pressure applying device 46. If the diameter of the tube shaped frame 41 is big or the insert blocks and pipes small more than one in- sert block and pipe could be placed within the frame. An insert block consisting of two insert block halves 20 according to the claimed invention are fitted around the pipe 47 and placed within the frame 41. The pipe 47 and the insert block fitted around the pipe 47. When the pipe 47, the insert block and the pressure applying device 46 are in the intended position within the tube shaped frame 31 the pressure applying device 36 is tensioned. This is done by screws 49 which extend in substantially the same direction as the pipe 47. When the screws 49 are tensioned and the pressure applying device is compressed a pressure is applied on the insert block which and the pipe transit is sealed.

The size of the insert block half 20, and consequently the an insert block, is selected to fit within the standard sizes used for sealing systems today, and the radius of the groove 21 is selected to match the specific pipe that the insert block half 21 will be fitted around. The size of the groove 21 must match the size of the pipe 37 to provide a reliably sealing around the pipe 37