GB2244782A

GB2244782A - Fireproof sealing system for bolted flanges

Info

Publication number: GB2244782A
Application number: GB9110303A
Authority: GB
Inventors: Hans J Tuckmantel
Original assignee: Kempchen and Co GmbH
Current assignee: Kempchen and Co GmbH
Priority date: 1990-05-23
Filing date: 1991-05-13
Publication date: 1991-12-11
Anticipated expiration: 2011-05-13
Also published as: GB2244782B; GB9110303D0; DE4113817A1; DE4113817C2; NL9100791A

Abstract

A sealing system for the sealing of pipelines (1) or vessels between flanges (2) which are joined together with the aid of flange bolts (3), having a strip- or ring-shaped sealing element (4) disposed in a seal seating gap (5) and terminating in front of or inside a flange compartment (6). To the outer edge of the sealing element (4) there is attached a fireproofing element (7) which in the case of fire liberates an intumescent or fireproof foam in the vicinity of the sealing system, the fireproof foam expanding to at least fill the flange compartment (8). <IMAGE>

Description

PIPELINE ETC. SEALING SYSTEM This invention relates to a sealing system for the sealing of pipelines and vessels between flanges which are joined together with the aid of flange bolts, having a stripor ring-shaped sealing element disposed in a seal seating gap and terminating in front of or inside a flange compartment.

The sealing element can more particularly but not necessarily be a metallic gasket, in the form for example of a corrugatedprofile gasket overlain with strips or rings of a soft or soft-resilient sealing material and/or with a foil or sheet of expanded and consolidated graphite. In the simplest case, the sealing element can be an "O"-ring or a series of two or more "0-rings. In any and every case, however, the sealing element is of a type which will fail to maintain safe sealing as soon as it is exposed to the high temperatures reached when for example the sealing system is exposed to a fire. The fire resistance of the entire sealing system as just described is thus in need of improvement and clearly inadequate under extreme conditions.

A basic object of the invention is to provide an improved sealing system of the type initially described, in such a manner that it will maintain adequate fire resistance even under extreme conditions.

According to the present invention there is provided a sealing system for the sealing of pipelines and vessels between flanges which are joined together with the aid of flange bolts, having a strip- or ring-shaped sealing element disposed in a seal seating gap and terminating in front of or inside a flange compartment, and a fireproofing element attached to the outer edge of the sealing element and the fireproofing element, in case of fire, liberates a fireproof foam in the vicinity of the sealing system, which fireproof foam expands to at least fill the flange compartment, and possibly erupt out of the flange compartment.

In all circumstances, the flange bolts are also encased in foam, so that the sealing element itself and the bolts remain functional and are protected against the thermal action from the seat of the fire, more particularly against radiant heating effects. Foam-producing fireproofing materials of a wide variety of types are available (cf. for example EP 0 003 772 and EP 0 138 546).

The invention arises from the discovery that the fire resistance of a sealing system of the type initially described can be significantly enhanced with the aid of foam-producing fireproofing materials, provided a fireproofing element is formed in the specified manner, attached as specified and thus combined with the rest of the sealing system components.

Various possibilities for further detailed adaptation and modification are within the scope of the invention.

Thus, the fireproofing element can have a metallic carrier and the fireproofing material can be placed on the metallic carrier. In the sealing of flanges with plain gaskets, the usual outer locating ring of the seal can also be coated with the fireproofing material. In this connection, it is possible to adapt the fireproofing elements as an integral part of the sealing element, more particularly by attaching the metallic carrier to the sealing element.

One particularly important embodiment of the invention is characterised in that the metallic carrier has holes for the flange bolts, and the fireproofing material is disposed on the metallic carrier outside and in front of the flange bolts.

It is usually sufficient to confine the fireproofing material to the areas outside and in front of the flange bolts, but in every case the flange bolts can be safely protected from fire damage in this way.

Another embodiment is characterised in that the fireproofing element is disposed partly in the seal seating gap, preferably attached to the sealing element, and projecting into the flange compartment. It is preferable in this case to extend the fireproofing element as far as the flange bolts, so that the latter are safely included in the protection zone. It is within the scope ofthe invention to make the fireproofing element as a separate additional component. For this case in particular, a preferred embodiment of the invention is characterised in that the fireproofing material is encased in a synthetic thermoplastic material, in which it is shaped to form the fireproofing element (cf. DE 37 27 271).It is within the scope of the invention to prepare the fireproofing element from a fireproofing material by injecting the latter into the flange compartment and/or the seal seating gap and hardening it in situ.

The invention will now be described in greater detail, with reference to a schematic drawing of embodiments thereof, purely by way of example, in which drawings: Figure 1 is an axial section through a sealing system of the invention; Figure 2 shows the system of Figure 1 during or after an outbreak of fire; Figure 3 is a corresponding view of Figure 1 of another embodiment of the sealing system of the invention; and Figure 4 shows a further embodiment, as in Figure 1.

The sealing system depicted in the Figures is intended for the sealing of pipelines 1, vessels and the like between flanges 2, which are joined together with the aid of flange bolts 3. The sealing system functions by means of a stripor ring-shaped sealing element 4, which is disposed in a seal seating gap 5 and teminates in front of or inside a flange compartment 6. It will be seen from Figures 1 and 3 that there is attached to the outer edge of the sealing element 4 a fireproofing element 7 which in case of fire liberates a fireproof material 10 to form a foam 8 in the vicinity of the sealing system. The fireproofing material 10 is selected and applied in amounts such that the foam 8 expands in case of fire to fill the seal seating gap 5 as far as required and at least the adjacent flange compartment 6, from which it may even erupt.Fireproofing materials 10 of the type in question expand into a foam 8, usually more than ten times the original volume, when the ambient temperature significantly exceeds a limit determined by their chemistry. The foam 8 remains heat resisting up to high temperatures, so that the space between the flanges 2 and beyond the flange bolts 3 remains full of the heat resisting foam 8. It is possible in this way to shield the sealing element 4 itself, together with the flange bolts 3, against radiant heat from heat or flames and thus significantly prolong their fire resisting life.

Figure 2 shows the fireproofing material 10 of Figure 1 expanding into Figure 8.

Figure 1 shows that the fireproofing element 7 has a metallic carrier 9, the fireproofing material 10 being disposed on the metallic carrier 9. In the Figure 1 embodiment, the metallic carrier 9 is attached to the sealing element 4.

In both the embodiment shown in Figure and the embodiment shown in Figure 3, the fireproofing element 7 is disposed partly in the seal seating gap 5, but extends into the flange compartment 6. In these embodiments it extends out to the flange bolts 3, so that the flange bolts 3 are safely protected as described.

In the embodiment shown in Figure 3, the fireproofing element 7 is a separate additional component. For this purpose, the fireproofing material 10 is encased in a synthetic thermoplastic material and shaped therein to form the fireproof ing element 7.

It is within the scope of the invention to inject a fireproofing material into the flange compartment 6 and/or the seal seating gap 5, where it is hardened to form a fireproofing element 7.

The embodiment shown in Figure 4 is of independent significance. It will be seen that the metallic carrier 9 has holes A through which pass the flange bolts 3. The fireproofing material 10 is disposed on the outer side, in front of the flange bolts 3. It could additionally be attached to the sealing element 4, but in any case it safely protects the flange bolts 3. It is also possible to cover the entire sealing system with a fireproof collar, surrounding the outer edges of the flanges 2.

Claims

1. A sealing system for the sealing of pipelines and vessels between flanges which are joined together with the aid of flange bolts, having a strip- or ring-shaped sealing element disposed in a seal seating gap and terminating in front of or inside a flange compartment, and a fireproofing element attached to the outer edge of the sealing element and the fireproofing element, in case of fire, liberates a fireproof foam in the vicinity of the sealing system, which fireproof foam expands to at least fill the flange compartment.

2. A sealing system as in Claim 1, wherein the fireproofing element has a metallic carrier and the fireproofing material is disposed on the metallic carrier.

3. A sealing system as in Claim 2, wherein the metallic carrier is attached to the sealing element.

4. A sealing system as in either of Claims 2 and 3, wherein the metallic carrier has holes for the flange bolts and the fireproofing material is disposed on the metallic carrier outside and in front of the flange bolts.

5. A sealing system as in any of Claims 1 to 4, wherein the fireproofing element is disposed partly in the seal seating gap and projects into the flange compartment.

6. A sealing system as in Claim 1 and either of Claims 4 and 5, wherein the fireproofing element is adapted as a separate additional component.

7. A sealing system as in any of Claims 1 to 6, wherein the fireproofing material is encased in a synthetic thermoplastic material and shaped therein to form the fireproofing element.

8. A sealing system as in any of Claims 1 to 6, wherein the fireproofing element consists of a fireproofing material which is injected into the flange compartment and/or the seal seating gap and hardened in situ.

9. A sealing system for the sealing of pipelines and vessels between flanges which are joined together with the aid of flange bolts substantially as hereinbefore described with reference to Figures 1 and 2 of the accompanying drawings.

10. A sealing system for the sealing of pipelines and vessels between flanges which are joined together with the aid of flange bolts substantially as hereinbefore described with reference to Figure 3 of the accompanying drawings.

11. A sealing system for the sealing of pipelines and vessels between flanges which are joined together with the aid of flange bolts substantially as hereinbefore described with reference to Figure 4 of the accompanying drawings.