DE20106824U1 - Modified chambered flat gasket - Google Patents

Description

Modified chambered flat gasket

The invention relates to the transport- and operationally safe integration of a sealing ring consisting of variably interchangeable materials with a special flank design on its circumference into a support ring made of metallic material, wherein this is carried out in particular by applying a slight prestress according to the principle of positive locking.

The new seal design is mainly suitable for the manufacture of flange seals with new possibilities for combining different materials and thus different property profiles. The range can be varied from acid resistance to ensuring high gas tightness at high operating temperatures.

Solutions are known from patent and technical literature as well as from the publication of company developments which, depending on the respective field of application in the flat gasket industry, are provided with or without profiling of the sealing surfaces and are equipped with visible or coated support rings which limit the surface pressure in order to protect the sealing material.

The German company Kempchen & Co GmbH, based in Oberhausen, which is well-known for its production of seals that meet special requirements, has taken on the development of these special shapes and has proposed, for example, surface-increasing, comb-profiled seals with and without overlays. As the surface pressure increases, the comb profiles must be covered with overlays made of e.g. PTFE, graphite, it, aluminum or silver in order to absorb the compression of the "combs".

The installation of such seals requires a high degree of assembly precision and the entire seal must be replaced after maintenance work.

As a further development, the H-shaped, cross-sectionally supporting and interlocking rings, preferably made of a hard and elastic material, have become known. The specially shaped seals are inserted into flanges with a wide variety of sealing strip geometries, whereby the sealing rings, which are embedded in opposite grooves of the supporting ring and have conical flanks pointing outwards, change from a pentagonal to an unequal-sided square cross-section due to surface pressure. They can be centered using a collar worked onto the support ring or an additional sheet metal centering.

For maintenance work, the sealing rings mentioned, which may also be present in pairs, can be easily replaced by a conical flank angle, which is also present here, but in the interest of a safe

During transport or in an already prepared storage situation, the sealing ring may become detached from its position and thus be exposed to damage. This may not be desirable for the intended applications in the areas of high-temperature, high-vacuum technology, chemistry and petrochemistry as well as reactor technology.

These disadvantages of the current state of the art, with regard to the development of special shapes in the flat gasket sector, must be overcome in a further step by introducing suitable measures.

The invention is therefore based on the object of offering a solution which improves the assembly and transport safety of flat gaskets, consisting of the known elements of support ring and sealing ring, by means of a novel geometry, whereby in addition to the desired form fit, the force shunt (KNS) can also be exploited and thus a cost-effective replacement of the sealing materials during maintenance work is possible in an expedient manner.

According to the invention, the problem is solved as follows, with reference to claim 1 for the basic inventive idea. The further development of the innovation results from claims 2 to 4.

Further explanations of the inventive solution will follow.

The new flat gasket consists of the main elements of a fixed support ring and the insertable gasket. There is no need to vulcanize or glue the latter in place, as the contact surfaces on the inner diameter of the support ring and the outer diameter of the gasket have "chambers" in the form of teeth that appear on the outside, thus preventing "shifting" within the support ring. The axially fixed position within the framework of the form fit and the use of an elastic pre-stress of the sealing material is particularly ensured by the fact that the "chambers" have alternating flank designs on the parallel contact surfaces across the width of the sealing material and the support ring, which correspond to a slight positive or negative inclination to the vertical of the complete flat gasket.

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Prepared pairs of support and sealing rings can thus be easily completed for assembly and cyclically planned maintenance work, whereby complex adjustments can be dispensed with right from the start.

The steel ring that holds the chambered seal usually limits the load moment for the sealing material.

In addition to the easy and quick assembly of both elements on site or in the sense of a possible

Due to the required quickly available storage of frequently used sizes, it is also an advantage that a "worn" seal is not completely unusable, but the ring-shaped chambered sealing material can be prepared for reuse by inserting a new one without damaging the support ring.

In addition to metallic materials, the stabilizing support ring can also be made of non-metallic materials, whereby the internal sealing material can also be variably adapted depending on the application for sealing liquids or gases that are under high pressure or are considered aggressive media.

The invention will be explained in more detail using an embodiment. Reference will be made to Figure 1, which shows the chambered flat gasket in plan view.

Figure 2 shows as detail "X" the position and shape of the support ring and inserted seal

The following reference symbols are used:

1 - Support ring

2 - Sealing ring

3 - Chambering

4 - Chambering

5 - Perpendicular

α - flank angle

The support ring 1, consisting of steel or PTFE, has on its inner diameter, for example, 6 chambers 3 arranged at regular intervals, into which the corresponding profiles of the sealing ring 2 engage.

In an analogous manner, the sealing ring 2 has chambers 4, offset by one step, which in turn correspond to the profiles of the support ring 1.

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The decisive advantage of the form-fitting fixation, which can be carried out under low pre-stress, is that the parallel chambers 3,4 in the present example, over the total of 12 existing "toothings" in alternating sequence, create a common flank inclination over the flank angle α, seen to the

Vertical 5. The flank angle α can advantageously take the value around 10°.

In this way, the axial position is already predetermined at the pre-assembly stage and during installation in a flange connection by means of the usual surface pressure to be applied, which guarantees a centric installation situation on all sides.

As a rule, the sealing ring 2 has the greater material thickness, whereby the support ring 1 limits its surface pressure in a conventional manner.

For example, fiber seals can be combined with a very acid-resistant PTFE chamber in a cost-effective manner according to the invention. On the other hand, there are other applications if pure graphite is combined with a pressure-resistant steel reinforcement and if mica protection rings are used in conjunction with pure graphite in order to increase the temperature limits for use in relation to oxygen.

Claims (4)

1. Modified chambered flat gasket, in particular for flange and cover seals, characterized in that a support ring ( 1 ) is in positive engagement via chambers ( 3 ) with the corresponding profiling of a sealing ring ( 2 ) on the one hand and the chambers ( 4 ) are in positive engagement with the profiling of the support ring ( 1 ) on the other hand. 2. Modified chambered flat gasket according to claim 1, characterized in that, in alternating sequence, the flanks of the chambers ( 3 , 4 ) and the flanks of the profiles assigned to them each have a positive or negative angle (α) inclined to the vertical 5 . 3. Modified chambered flat gasket according to claim 1 and 2, characterized in that the chambers ( 3 , 4 ) and the profiles associated with them are variable in shape and number. 4. Modified chambered flat gasket according to claim 1, characterized in that the sealing ring ( 2 ) preferably has elastic properties.