The invention relates to a method of installing a heating pipe, wherein a plastic pipe acting as a water circulation pipe is fitted within a casing pipe after the installation of radiators, the plastic pipe being connected to the terminals of the radiators, and to an arrangement for connecting a heating pipe to a radiator.

Previously the use of plastic pipes as water circulation pipes in the heating systems of apart¬ ments and buildings has been problematic. Among other things, this is due to the fact that a plastic pipe cannot be bent sharply for reasons of flowing tech¬ nique. The bending radius has to be at least 10 times the diameter of the pipe.

For this reason, plastic pipes in one-family houses, for instance, have been brought from below in a sand layer so that it has been possible to make the bending radius sufficiently large. Due to the large bending radius, it has not been possible to install plastic pipes on the surface of a cavity slab con¬ struction, for instance. A further problem with the use of plastic pipes has been that plastic pipes are liable to impacts so that the pipe portion visible between the floor and the radiator is easily damaged, causing water damage. Still another drawback is that it is often necessary to install pipes protruding from the floor in an oblique position, which is aesthetically a poor solution. The oblique position results from said large bending radius.

The object of the invention is to provide a method and an arrangement by means of which the draw- backs of the prior art can be eliminated. This is

achieved by means of a method and an arrangement of the invention. The method of the invention is characterized by cutting off the plastic pipe in such a manner that the ends of the pipe are positioned substantially close to the terminals of the radiator to be connected; fitting a connection box open at the top in the end of the casing pipe; displacing the connection box fitted to the casing pipe relative to the plastic pipe so that the end of the plastic pipe projects outside the connection box; connecting a branch pipe comprising a sharp bend to the plastic pipe; displacing the connection box relative to the plastic pipe so that the end of the plastic pipe is positioned within the connection box and the branch pipe projects from the box substantially upward; and locking the branch pipe and the end of the plastic pipe within the connection box by inserting at least one locking block into the connection box, the lock¬ ing block allowing vertical movement of the end of the plastic pipe. The arrangement according to the invention, in turn, is characterized in that the ar¬ rangement comprises a connection box and a branch pipe, the connection box comprising a housing portion open at the top and at least one clearance portion protruding from said housing portion and having one end arranged to be connected to the casing pipe, the clearance portion being an elongated part arranged to substantially fit the casing pipe so that the connec¬ tion box is displaceable relative to the casing pipe in the direction of the casing pipe so that the end of the casing pipe will be positioned closer to the housing portion, whereby the end of the plastic pipe within the casing pipe is arranged to be passed through the open top of the housing portion outside the connection box to interconnect the branch pipe

and the radiator.

A major advantage of the solution of the inven¬ tion is that the pipe can be installed within a 5 cm surface casting layer and the pipe is nevertheless fully replaceable later on and the visible part of a finished pipework does not differ from traditional metal pipe installations. A further advantage is the simplicity of the method and the arrangement with resultant very low installation costs and rapid in- stallation. Still another important advantage is that the pipe can be replaced simply, which reduces costs in case of damage.

In the following the invention will be de¬ scribed in greater detail by means of preferred em- bodiments shown in the attached drawing, wherein

Figure 1 is a general view of a heating pipe system installed according to the method of the in¬ vention;

Figure 2 is a general view of the arrangement of the invention in connection with a heating pipe system;

Figure 3 shows a second preferred embodiment of the arrangement;

Figure 4 is a side view of a third embodiment of the arrangement of the invention;

Figure 5 is a top view of the embodiment of Figure 4; and

Figure 6 shows a detail developed for applying the method of the invention. Figure 1 is a general view of a radiator-pipe¬ work system installed according to the invention. The radiators are indicated with the reference numeral 1 and the pipework generally with the reference numeral 2. In the example of Figure 1, the floor is formed by cavity slabs 3 covered up by a surface layer 4 of

concrete having a thickness of about 5 cm.

Figure 2 is a detailed view of an arrangement providing a connection between the pipework 2 and the radiator 1. The pipework 2 comprises a casing pipe 5 and a plastic pipe 6 acting as a water circulation pipe. The casing pipe 5 is preferably made of a plas¬ tic material.

According to the method of the invention the casing pipe 5 is first disposed on the surface of the cavity slabs 3. The length of the casing pipe 5 can be greater than the length of two successive radi¬ ators 1, whereby the casing pipe winds from one radi¬ ator to another. Then the plastic pipe 6 is inserted within the casing pipe 5. The plastic pipe is dis- posed freely within the casing pipe 5.

At the following step the plastic pipe 6 is cut into a suitable length so that the pipe ends are po¬ sitioned substantially close to terminals 7 in the radiator 1 to which the pipe is to be connected. A connection box 8 is then fitted in the end of the casing pipe.

The connection box 8 comprises a housing por¬ tion 9 open at the top and a clearance portion 10 protruding from the housing portion, the end of the clearance portion being arranged to be connected to the casing pipe 5.

At the following step the connection box 8 is displaced relative to the plastic pipe 6 so that the end of the plastic pipe can be guided so as to extend through the housing portion 9 open at the top out¬ side the connection box 8. This displacement can be carried out in various ways. In the solution of Fig¬ ure 2, the clearance portion 10 of the connection box 8 is elongated so that the connection box 8 can be pushed towards the casing pipe, the clearance portion

10 being thereby inserted into the casing pipe 5 in a piston-like manner, and the end of the plastic pipe 6 can be led through the open top of the housing por¬ tion 9 outside the connection box 8. A branch pipe 11 comprising a sharp bend is then attached to the end of the plastic pipe 6, which at this stage extends outside the connection box 8, that is, in Figure 2, to the left side of the connec¬ tion box. The branch pipe 11 is made of metal. It can be attached to the end of the plastic pipe 6 in various ways. In the example of Figure 2, one end of the branch pipe 11 is so shaped that it can be in¬ serted within the plastic pipe 6. Thereby the connec¬ tion can be made, e.g., by fitting a copper ring 12 around the plastic pipe. The copper ring can be clamped around the end of the plastic pipe and that of the branch pipe by means of a suitable clamp de¬ vice, as shown in Figure 2.

At the following step the connection box 8 is displaced in a direction towards the plastic pipe 6 so that the end of the plastic pipe 6 will be posi¬ tioned within the housing portion 9 of the connection box and the branch pipe 11 projects from the box sub¬ stantially upward. In the example of Figure 2, this displacement is carried out by pulling the connection box outward from the casing pipe over a sufficiently long distance, whereby the end of the plastic pipe is displaced back to the point shown in Figure 2.

The end of the plastic pipe is then locked in position by pushing at least one locking block 13 from above into the connection box 8 within the hous¬ ing portion 9 of the connection box 8. The locking block/blocks 13 comprises/comprise a recess such that it allows the displacement of the end of the plastic pipe vertically but not sidewardly. This is of im-

portance when the branch pipe 11 is connected to the terminals 7 of the radiator 1. The branch pipe hole in the locking block 13 may be eccentric as well. The upper surface of the locking blocks is flush with the edges of the housing portion to achieve an even final floor surface. The locking blocks can be locked with¬ in the housing portion by a suitable snap-action con¬ nection, for instance, simultaneously ensuring that the blocks are properly positioned. Furthermore, a groove 14 extending around the housing portion can be formed between the locking block 13 and the upper edge of the housing portion. This detail makes it possible to cut a carpet 15 in an advantageous manner if the pipe 6 is to be reached later on. It is also advisable to make the locking blocks slightly lower than the housing portion 9, whereby possible im¬ purities on the bottom of the housing portion will not prevent the locking blocks from assuming their proper position. At the following step the branch pipe 11 is attached to the radiator in any known manner. This process is repeated with each radiator, and finally the cavity slabs 3 and the pipework are covered up with surface concrete, the desired carpet or the like being spread on the concrete.

The present method enables rapid installation as it is to be noted that the pipe 6 need not be dis¬ placed, that is, the pipe 6 can be fixed at one end, for instance, and nevertheless the installation work can be carried out in a very advantageous manner.

Figure 3 shows the second embodiment 18 of the connection box. The connection box comprises a housing portion 19 and a clearance portion 20. The casing pipe is indicated with the reference numeral 5. In the embodiment of Figure 3, a sleeve member 21

is fitted in the end of the casing pipe 5 and arranged to be slideably fitted in the clearance por¬ tion 20.

Figures 4 and 5 show the third embodiment of the arrangement. The connection box is indicated with the reference numeral 28. The housing portion is in¬ dicated with the reference numeral 29 and the clear¬ ance portion with the reference numeral 30. The casing pipe is indicated with the reference numeral 5 and the plastic pipe correspondingly with the refer¬ ence numeral 6. In the embodiment of Figure 4, the branch pipe and the plastic pipe are connected to¬ gether by a threaded part 31. The threaded part 31 can be attached to the plastic pipe in any manner known per se. In the embodiment of Figure 4, it is essential that the clearance portion 30 is so shaped that the threaded part 31, that is, the connecting part between the plastic pipe and the branch pipe can be displaced within the clearance portion 30 by dis- placing the plastic pipe 6 relative to the casing pipe 5. The significance of this detail becomes ap¬ parent in connection with the replacement of the pipe 6, whereby the connecting work can be carried out in an advantageous manner as the ends of the plastic pipe can thereby always be passed outside the connec¬ tion box, which enables the connections to be made rapidly. On account of the threaded connection, the connection box is in this embodiment provided with shoulders 32 which prevent the turning of the thread- ed part 31 when the branch pipe is screwed onto the threads on the threaded part 31.

As already mentioned above, the displacement of the connection box relative to the plastic pipe 6 can be ^' carried out in various ways. Figure 6 shows one preferred alternative. The casing pipe is indicated

with the reference numeral 5 and the plastic pipe correspondingly with the reference numeral 6. The casing pipe is provided with an expansion means 40 formed by two portions 41, 42 telescopically moveable relative to each other. Due to the expansion means the connection box (not shown in Figure 6) connected to the casing pipe can be displaced relative to the plastic pipe so that the end of the plastic pipe can be passed outside the connection box. In the embodi- ment of Figure 6, the connection box can be connected to the casing pipe, e.g., as shown in Figures 2 to 5. It is to be noted that it is not necessary in this embodiment to displace the connection box relative to the casing pipe; the displacement, however, is possible if required.

As is apparent from the above, a pipe connec¬ tion can be made in a very simple way according to the invention. The work is easier to carry out when a chute 43 is formed in the housing portion of the con- nection box, which chute passes the plastic pipes automatically to the right position when the end is positioned outside the connection box. The chute 43 is shown in Figure 5. The housing portion can further be provided with a guide 44 which guides the locking ring 12 automatically to the right position for making the connection. The guide 44 is shown in Fig¬ ure 2, for instance.

The above examples are by no means intended to restrict the invention but the invention can be mod- ified completely as desired within the scope of the claims. Accordingly, it is obvious that the arrange¬ ment or its parts need not necessarily be exactly similar to those shown in the figures, but solutions of other kinds are possible as well. The housing por- tions, for instance, can be of any shape; the housing

portion can be round as shown in Figure 5 or square- shaped, rectangular, etc. The connection box can be made of any suitable material, such as plastic, metal etc. The connection box can be attached to the casing pipe in other ways than by the friction-based connec¬ tion shown in the figures. The expansion means 40 need not, either, be such as shown in Figure 6, but it can simply be in the form of straight pipe at¬ tached at both ends to the casing pipe so that the ends of the casing pipe can be displaced toward each other and away from each other. The casing pipe and the expansion means in the form of a straight pipe can be interconnected, e.g., similarly as the connec¬ tion box and the casing pipe in the embodiment of Figure 2. The connection box can comprise two parts with two identical clearance portions protruding out¬ ward from it.