The multiple wall angle connection allows to connect pipes and containers with great flexibility and a good compensation of the heat expansion. To connect two pipes (1, 2), for example, three coaxial angle connections (3, 4, 5) are interconnected. The internal connection (5) is connected to the first pipe (1) and the external connection (3) to the second pipe (2). The connections are interconnected by junction pieces (7) of semi-toric shape arranged at each side, at respective ends. Straight pipe portions (9-13 and 19-23) can be provided between the connections and the junction pieces. They can be cylindrical or conic. Control apparatus can be inserted within the space comprised between the different connections.

The instant invention relates to a pipe connection of two pipelines 
preferably disposed at an angle to one another. In the construction of 
facilities, the individual parts of which are connected to one another by 
pipelines, there is a striving generally, for reasons of flow technology 
and cost, to manage with the shortest possible pipelines and, for this 
purpose, to construct as compactly as possible with consideration to other 
vital viewpoints, for example, the accessibility for monitoring and 
repairs. This viewpoint applies to an amplified extent in 
nuclear-technological facilities and therein, in turn, especially for the 
primary zone of a nuclear reactor, amongst others to keep costly radiation 
shielding to as little as possible at the periphery. These viewpoints are 
opposed by the necessity of caring for the reduction of the stresses which 
are produced by the thermal expansion of the pipelines per se and the 
parts of the facilities connected thereby. In nuclear-technological 
facilities with the temperature thereof consisting of several hundred 
degrees Celsius, the thermal expansions can reach such a considerable 
scale as to force a "yielding" suspension of the pipelines. Compensation 
can be effected in zones which are less vulnerable from the 
safety-engineering standpoint by corrugated tube compensators, the 
introduction of which into the primary circulation of nuclear reactors 
being, however, a subject of concern. The possibility is provided here 
only of providing the pipelines with an expansion capability in the form 
of loops which, however, have a large space occupancy. To increase the 
flexibility of such loops, it is known (German Published Prosecuted 
Application DE-AS No. 15 25 842) to divide the pipeline in the vicinity of 
the loop into several mutually parallel connecting pipes of smaller 
diameter which, however, raises various problems with respect to flow 
engineering and manufacturing technology especially for lines conducting 
liquid metal. 
The problem of the instant invention is to provide a curved connection of 
two pipelines which has a high elasticity and thus permits, within a very 
small space, the compensation of considerable thermal expansions in 
pipelines. The connection should, moreover, also suffice for meeting the 
other requirements that are to be met by a pipeline, for example, with 
regard to testability, even after a given operating period. Curved 
connections of two pipelines disposed at an angle to one another lend 
themselves especially well to a use as expansion compensation members, 
because such bends are more flexible than straight pipe lengths. 
The solution for the problem is effected by a band connection for pipelines 
and vessels, comprising a first and a second pipeline, a multiplicity of 
coaxial spaced-apart pipe bends disposed within each other, the pipe bends 
including at least an outer, an inner, and at least one middle pipe bend 
each having ends, one of the ends of the outer pipe bend being integral 
with the second pipeline, one of the ends of the inner pipe bend being 
integral with the first pipeline, and half torus-shaped connecting pieces 
connecting one of the ends of the at least one middle pipe bend to the 
next inner pipe bend and connecting the other of the ends of the at least 
one middle pipe bend to the next outer pipe bend. The connection of 
mutually coaxial pipe lengths of varying diameters at the ends thereof by 
means of half torus-shaped connecting members is known from German Pat. 
No. 22 59 584, which is concerned, at any rate, with an elastic 
lead-through of pipelines through the wall of a nuclear reactor 
containment. In the proposed curved connection, the individual pipe bends 
are connected, so to speak, in series, and forces or moments applied from 
the outside travel therethrough one after the other and stress them to an 
equal extent. The deformation of the entire connection results from the 
sum of the individual deformations for each pipe bend, as the man of skill 
can calculate it with the aid of the known method described, for example, 
in H. Hampel: "Pipeline Statics", Berlin 1972, page 128 et seq. Also 
proposed is that the number of the pipe bends encased within one another 
are three, five, seven and so forth, if two pipelines are connected to one 
another. On the other hand, if a pipeline is additionally connected with a 
vessel or container, then the number of the pipe bends encased within one 
another is two, four, six and so forth. 
The straight pipe lengths which are furthermore to be connected between the 
pipe bends and the half torus-shaped connecting members, have the problem 
of equalizing or just permitting the varying elliptical deformation of the 
curved pipe cross section, because this is prevented by direct fastening 
of the connecting members. In a three-shell curved pipe, for example, the 
deformation of the middle shell with respect to the outer and inner shells 
is offset through 90.degree.. 
The frustroconical shape of the straight pipe lengths which is additionally 
proposed in has the effect that with only negligibly increased dimensions 
a larger path for the bending is available than with the use of 
cylindrical pipe lengths, with, of course, increased manufacturing expense 
.

It is, of course, also possible to produce other connections, for example 
also those with a 180.degree. angle. A first pipeline 1 is to be connected 
to a second pipeline 2 disposed at a right angle thereto, it being assumed 
that the flowdirection is from the first into the second pipeline. The 
connection in the example is formed of three pipe bends 3,4,5 disposed 
within and coaxial to one another, the inner pipe bend 5 being connected 
at the one end thereof to the first pipeline 1, and the outer pipe bend 3 
at the one end thereof through a conical intermediate member 14 to the 
second pipeline 2. A straight cylindrical pipe length 11 is added to the 
free end (FIG. 1) of the inner pipe bend 5, and another straight 
cylindrical pipe length 12 to the free end of the outer pipe bend 3. The 
middle pipe bend 4 likewise has at both ends thereof straight cylindrical 
pipe lengths 10 and 13, respectively, of equal length with the foregoing. 
The straight pipe lengths 12 and 13 or 10 and 11, respectively, are 
connected to one another by half torus-shaped (of U-shaped cross section) 
connecting pieces 6 and 7, respectively. The term "torus", in this 
connection, is supposed to include also such annular members having a 
cross section deviating from a pure circular shape, for example, 
elliptical. The spacing between the pipe bends is of such dimension that 
they and the pipe lengths connected thereto, respectively, do not come 
into contact with one another during the anticipated bendings. This is 
achieved in an alternate embodiment (FIG. 2) by the frustoconical 
construction of several of the straight pipe lengths, identified here by 
19,22,23 whereas the others, here 20,21 are cylindrical. The opening of 
the frustum of the cone is, in this regard, located on the side lying 
opposite the pipe bends 3,4,5. In a pressure transmitting pipeline, the 
outer pipe bend 3 and the inner pipe bend 5 are loaded from the inside, 
the middle pipe bend 4, however, is loaded from the outside, which must be 
taken into account in the dimensioning of the wall thickness thereof. The 
spacing between the inner pipe bend 5 and the middle pipe bend 4 and the 
straight pipe lengths connected thereto can be of such dimension that 
inspection instruments, for example for examining welding seams, can be 
introduced into the gap intermediate thereto. If necessary, a drain 
opening, not illustrated here, can be provided at suitable locations (in 
the connecting piece 6 here) in order to drain off liquid filling the 
intermediate space between the individual pipe bends. In another device, 
for example, turned upside down, a blow-off opening can serve for 
degassing the pipe connection. 
It is immediately apparent that the demand for additional space for the 
proposed curved connection as compared to a simple pipe bend is only very 
small. For a pipeline of the nominal width (NW) 550 with a wall thickness 
of 10 mm (which is also true for the inner pipe bend 5) and a spacing of 
the individual pipe bends from one another of 20 mm, an increasing in 
bending elasticity of about 100% with respect to the simple curved 
connection is produced.