NL1035548C2 - Coupling piece with flange, pipe system with at least one such coupling piece, method for connecting a pipe and a coupling piece, and device for connecting. - Google Patents

Abstract

The invention relates to a coupling piece (1) for connecting to a flexible conduit (2) formed substantially from plastic, comprising a socket for receiving therein at least one end part of at least one conduit, and a flange (4,5) at a distance of at least approximately a wall thickness of the conduit from the inner side of the socket, wherein at least the inner side of the socket and the flange are formed from thermoplastic material.

Description

CONNECTION WITH FLANGE, PIPE SYSTEM WITH AT LEAST ONE SUCH CONNECTION, METHOD FOR CONNECTING A PIPE AND CONNECTION, AND CONNECTION DEVICE

The present invention relates to various aspects which are related to systems comprising plastic pipes comprising (KLS).

A KLS is used in the known art for many applications, such as drainage of water, supply of water, gas and chemical substances. During the last ten years, KLS have increasingly found their way into Dutch construction as an alternative to steel and copper. KLS for disposal is generally known, among other things through the introduction of PVC. For the supply of hot and cold water and gas and central heating and drinking water 15, partly in view of a required pressure resistance, until recently only copper pipes were used. Due to the high price of copper, as well as copper theft on construction sites, KLS has made a rapid advance, which has not yet been achieved. Simplifications of KLS with regard to their assembly have also led to KLS being accepted by the authorities and being used more and more by installers. It is noted that in many countries KLS has already been used for tap water because the quality thereof is sometimes so limited that the use of metal in pipes is not desirable.

KLS can comprise various types of plastics, with or without a base of, for example, aluminum embedded in plastic to improve the pressure resistance. Thermoplastic plastics are usually used, such as polypropylene (pp), polyethylene (pe), polybutylene (pb) and sometimes PVC. The installation of a system comprises the formation of combinations of pipe and connection pieces, couplings and / or fittings. The type of fitting also determines the nature of 1035548 2 tools to be used. Incidentally, there are more and more systems that do not require any tools at all, the so-called push couplings.

5 The following division can be made into systems that are most widely used in Europe and the world:

Type of plastic Type Characteristic Application Market connection

Cross-linked poly-Axial Flexible, Water / gas 20% ethylene pressverbin Central (VPE) -ding; heating

Radial press connection VPE or PE-RT Axial Form-retaining, Water / gas 60% with flexible press layer aluminum layer; oxygen proof,

Radial vulnerable press connection - polypropylene sleeve welding - Strong, drinking water, 15% exclusively for chemical welding, inexpensive fitting, not flexible

Polybutilene Push fitting Only 5% flexible

No tools

Small diameters

Of the above KLS, the most commonly used are the 10 multi-layer tubes (PE tubes with aluminum base layer, often 3 on the outside and embedded on the inside in the plastic).

With an estimated market share of 60%, these systems are the most used in the built environment. The big advantage of these systems is that they can be bent to retain their shape, just like copper pipes, but that they are much lighter in weight and cheaper. The disadvantage of these known systems is that the fittings or couplings are expensive.

The seal, even under pressure, is obtained by means of an o-ring on the coupling piece. The coupling piece is inserted or pushed into the pipe or tube. The coupling piece is then squeezed shut with great force over the pipe or tube by means of a sleeve.

In another known example, the tube is produced with a thicker tube wall, so that an axial press connection can be made: the tube is screwed up, the fitting is inserted into it and then a thick brass sleeve is slid over the tube making the fitting its gets clamping force.

All such known systems have as a joint property that a variety of tools must be used and the high price of the coupling piece or fitting. A limited advantage of such systems is that no o-ring is used, so that it can have a "certain" appearance.

In the last two years there are also push connections available for pipes or tubes with an aluminum base. These are indeed handy, but on the other hand are expensive and exhibit a not insignificant risk, due to the o-ring, of leakage in combination with apparent convenience. They are not recommended in concrete-like floors. All these KLS therefore have connections of metal with plastic and / or o-rings.

4

As is also apparent from the table, polypropylene pipes and connectors and fittings are also used. One possibility to achieve this involves the use of welding fittings. These fittings are welded to the tube with the aid of a welding device (polyfusion welding). An advantage hereof is that the coupling piece will form one whole with the pipe or tube. Furthermore, there is hardly any narrowing. This offers a high degree of certainty. However, the pipe or tube cannot be deformed manually, so that a rigid tube is generally used. Partly for this reason, a flexible pipe is often used in the final assembly (above the concrete). A welding machine must therefore be used at all times if one wants to connect to the pp pipe. Also, a PP pipe or tube is usually not oxygen-tight, which makes it less suitable for central heating systems.

Currently, more and more applications are being made of these pipes as an alternative to steel pipes in offices for heat and cooling ceilings. The connection is fast and relatively cheap and lends itself very well in prefabrication.

According to the present invention, as it is now presented and defined in the appended claims, a coupling piece, a pipe system, a method and a device have been developed.

In summary, the invention, as defined in the independent claims, embraces a coupling piece made of thermoplastic material, such as PE-RT (a reinforced PE), many of which are already being made now. This coupling piece is provided on the inside with a flange, which can also be referred to as an additional sleeve or inner tube. When the pipe is inserted into the coupling piece and after the pipe and the coupling piece have been heated up, the end face of the pipe which is inserted into the coupling piece is transferred over the width of the flange, for example 3.5 mm. and thus protected by this flange. When both the inside of this coupling piece and the flange or collar or additional sleeve are heated, as well as the inside and outside of the pipe or tube, the pipe and the coupling piece will thus be bonded to each other in a very reliable manner. In embodiments with an aluminum base layer in the pipe, after the connection of the coupling piece and the also heated pipe, optimum adhesion and shielding of the aluminum layer results.

Such a shielding is necessary in such an embodiment, because otherwise corrosion will occur on the aluminum in the tube and this corrosion would continue to attack the base layer of aluminum until a leakage occurs. The inner adhesion at the flange is also desirable, often not even necessary, to ensure adequate tensile force. If the flange were not used for this, the fitting would only adhere to the outside of the tube and this may be insufficient under certain circumstances if the thin layer of thermoplastic plastic is taken into account over or on the aluminum base layer.

The pipe and the coupling piece are heated with at least one welding machine, but usually with two welding mandrels: one for the fitting and one for the tube. The welding mandrels are part of the system and with that the method can also be realized. The welding mandrels can be a resp. have a shape adapted to the pipe and the coupling piece, so that the pipe and the coupling piece are heated in the correct form. This does not necessarily have to be desirable or convenient under all circumstances.

The invention combines the advantages of a form-retaining but flexible or at least bendable pipe or tube of, for example, PE, optionally with an aluminum base layer 6 therein, and the advantages of a welded connection. A secure and reliable connection can be achieved without having to use metal couplings with 0-rings. Moreover, the price, in particular for large pipe diameters, is a factor of 10 cheaper. For many installers in Europe, this cost price is another reason to stick to the trusted steel or copper with larger diameters and not to use KLS.

There is also an advantage for users of PP pipes and 10 matching connectors. In the future, the pipe can be flexible and dimensionally stable, but also bendable and, moreover, also oxygen-tight. It is therefore expected that users will be able to switch from the background of PP pipes and from the background of pipes with aluminum base layers to the thus provided system according to the invention, which also benefits uniformity.

A still further advantage is that at those moments where no weld connection can be made, in particular where no electricity is available or in places that are difficult to reach, a press coupling or screw coupling can simply be placed, which in the case of pipes and PP connectors is not possible.

Below, an embodiment of the present invention will be described in conjunction with and with reference to the accompanying figures, which embodiment is non-limitative of the present invention, and in which the same reference numbers can be used for various individual figures and views for identical or similar components, elements and aspects, and in which; 7

FIG. 1 schematically shows a method for assembling a coupling piece and a pipe for forming a pipe system;

FIG. 2 shows the composition according to arrow II of a pipe;

FIG. 3A and 3B show steps in a method for connecting a connector to a conduit according to the present invention; and

FIG. 4 shows a side view in cross-section along the line IV-IV in FIG. 3B.

Fig. 1 shows a coupling piece 1 according to the present invention, which is connected with a method according to the present invention to a pipe 2 for forming a pipe system, as an assembly of coupling pieces and pipes according to the present invention, wherein use can be made be made from a device, also according to the present invention, some of which are shown in FIG. 3A.

The coupling piece 1 is thus shown in FIG. This is sleeve-shaped or tubular. A stop 3 is arranged in the center of the interior of the tubular coupling piece 1, but it can also be displaced over a desired distance relative to the center of the coupling piece 1. At the stop there is a rearward direction in FIG. 1 and a flange 5 extending in the forward direction in FIG. 1 is provided. The flanges 4, 5 therefore extend in opposite directions from the stop 3.

Below the flanges 4, 5 and against the stop 3, the extreme edge of a pipe 2 can be inserted, namely, the pipe 2 has a slightly smaller diameter 6 with respect to the inner diameter 7 of the coupling piece 1. The wall thickness 8 of the pipe 2 corresponds closely to the distance between the inner wall of the coupling piece 1 and the flanges 4, 5, so that the pipe 2 can be inserted under the flange 4 and against the stop 3 in the direction of arrow A.

A viewing hole 18 can be provided in the coupling piece 1 for optically assessing whether the pipe 2 is slid sufficiently deep into the coupling piece 1 after heating. It is preferable if the viewing hole 18 is situated in the vicinity of the center of the coupling piece 1, such that the interior of the flange 4,5 becomes visible at the stop stop. Multiple viewing holes can be provided on both sides of the stop 3.

Fig. 2 shows the composition of a conduit 2 as it is applicable in a possible embodiment of the present invention. A base layer 9 is made therein of aluminum with layers 10, 11 on either side thereof with adhesive or glue or the like, and the inner surface of the pipe and the outer surface of the pipe 2 are each covered with layers 12, 13 of thermoplastic material, in particular polyethylene, e.g. PE-RD (polyethylene, raised temperature).

Because the extreme edge 14 of the conduit 2 can be protruded under the overhang of at least one of the flanges 4, 5 in Fig. 1, in particular the aluminum of the base layer 9 is well protected and transferred and enclosed by thermoplastic plastic which is essentially inert to corrosion and other harmful influences. The coupling piece according to the invention is of course also applicable to pipes without aluminum base layer 9 or with a layer of other material. Moreover, a good seal can be obtained, for example with the method to be described below.

As shown in Fig. 3A, that each of the coupling piece 1 and the pipe 2 can be placed on a respective heating element 9. The coupling piece 1 can be placed on a heating element 15, which is bus-shaped and has the same dimensions as the conduit 2. Thereby the inner surface of the coupling piece 1 can be heated to a plastic state. If the heating element 15, which is connected to, for example, a voltage source for generating the required heat, has the same thickness as the pipe 2, at least one of the flanges 4, 5 can hereby also be heated to a plastic state. To this end, the coupling piece 1 can be placed on the heating element 15 in the direction of double arrow B or can be slid over it, or the heating element 15 can be slid into the coupling piece 1. The coupling piece 1 and the heating element 15 are then separated again.

Simultaneously or shortly before or after, the pipe 2 is inserted into or between 2 heating elements 16, 17, both of which are bus-shaped or cylindrical, and are arranged concentrically. Furthermore, the heating elements 16 and 17 are each connected to a voltage source for supplying electric power and bringing the heating elements 16 and 17 to a higher temperature. If the line 2 is then inserted between the heating elements 16 and 17, the temperature of the inner surface and the outer surface of the conduit 2 are heated to a temperature where the materials on the inner surface and on the outer surface have become plastic. Here too, a double arrow C is shown to make it clear that there is a relative movement of the assembly of the heating elements 16, 17 with respect to the pipe 2, 30 and with the arrows D and E respectively the heated ends of the coupling piece 1 and the pipe 2 face each other. This is followed by the movement shown in Fig. 3B. Namely, then the pipe 2 is inserted into the coupling piece 1 in the direction of arrow F, or the coupling piece 1 is slid over the free end of the pipe 2. This situation is further shown in FIG.

In Fig. 4, the conduit 2 is shown to comprise an aluminum base layer 9 per tube. This base layer 9 is coated on the inside and on the outside with layers 12, 13 of thermoplastic material, in particular polyethylene. The material of the coupling piece 1 can contain polypropylene or any other thermoplastic material. In the state of Fig. 4, the inner surface of the coupling piece 1 and at least one of the flanges 4 are heated, whereby possibly also the stop 3 or even the other of the flanges 5 can be brought into a plastic state. The layers 12, 13 of the conduit 2 have also been brought into a plastic state. Before the various materials have cooled down to a lower temperature again than the lower limit for the plastic state, the coupling piece 1 and the pipe 2 are brought together. The free end of the pipe 2 then ends up between the inner surface of the coupling piece 1 and the flange 4, possibly even against the stop 3. The outer layer 12 of the pipe 2 will thereby adhere to the inner surface of the coupling piece 1, and an annular inner surface of the material of the inner layer 13 of the conduit 2 will adhere to the flange 4. The flange 4 has an anchor shape in combination with the flange 5 and the stop 3. A good engagement or clamping can thus be achieved. from the free end of the conduit 2. The point shapes at the ends of the flanges 4, 5 can also drill into the plasticized material of the inner covering layer 13 of the conduit 2 to achieve an even better seal. In a specific embodiment 11 of a method according to the invention, the front end of line 2 is calibrated and slanted at an angle k before it is slid between the heating element 16, 17. After heating, the angle k falls into the cavity at arrow F (Fig. 4) which can have the same angle as the chamfered side. The reason for this is to obtain a larger welding surface (pytagoras scaffolding = sloping side is a larger surface). Another reason is that the flange 4 may have such a maximum size that, if heating takes place for (too) long, there is no restriction in the connection.

After taking cognizance of the foregoing, many alternative and additional embodiments will occur to those skilled in the art, all of which are within the scope of the present invention, insofar as they at least comply with the definitions defined in the appended claims by letter 15 or in spirit. It is thus possible that even other thermoplastic materials are used than the aforementioned polyethylene or PE-RT. the stop does not have to be a continuous ring, but only serves to keep the flanges 4, 5 at a distance from the inner surface of the coupling piece 1. The coupling piece 1 does not have to be a sleeve to define a continuous passage. The coupling piece 1 can also be an end cap, or a T-junction, or any other connecting element. The coupling piece 1 can on the one hand also be provided with screw thread, for example to form a connection with an external component, for example the screw thread on the outside of a tap, whereby screw thread can then be arranged on one side in the interior of the coupling piece 1. It is also possible to arrange a threaded element over the coupling piece 1, wherein counter-thread can then be defined in the outer surface of the coupling piece 1. Only the heating elements are shown of the device for realizing the method according to the invention, which elements are as it were negatives of the elements and components to be heated, in particular the coupling piece and the pipe. Other components and aspects of such a device are well within the reach and ability of the conventional or average person skilled in the art, so a further consideration or description thereof is omitted. Nevertheless, it will be clear that a device for realizing the method and then in conjunction with a coupling piece according to the present invention, optionally in combination with a pipe, is all within the scope of the present invention, as defined in the appended claims.

It is also possible, within the scope of the present invention, to provide the flange in the form of a tube separate from the sleeve, which, if desired and depending on the circumstances, can be arranged in the pipe without abutment.

1035548

Claims (11)

1. Coupling piece for connection to a flexible pipe formed essentially of plastic, comprising a sleeve for receiving at least one end part of at least one pipe, and a flange at a distance of at least approximately a wall thickness of the pipe from the pipe. inside of the sleeve, wherein at least the inside of the sleeve and the flange are formed from thermoplastic material, wherein the thermoplastic material is one from the group comprising: polyethylene (PE), reinforced PE, PE- RT (PE-Raised Temperature). Coupling piece according to claim 1, further comprising a stop between the sleeve and the flange. 3. Coupling piece according to claim 2, wherein the stop is made of a thermoplastic material. Coupling piece according to at least one of the preceding claims, wherein the sleeve can be pressure-deformed in the unheated state. A pipe system comprising at least one pipe formed from substantially plastic and a coupling piece for connection to the pipe, which coupling piece comprises: a sleeve for receiving therein at least one end part of at least one pipe, and a flange at a distance of at least approximately a wall thickness of the pipe from the inside of the sleeve, wherein at least the inside of the sleeve, the flange and the inner and outer wall of the pipe are formed from thermoplastic material, the thermoplastic material being one of them the group comprising: polyethylene (PE), reinforced PE, PE-RT (PE-raised temperature). 6. Pipe system according to claim 5, further comprising at least one additional pipe, which can also be connected or connected in and with the sleeve. 7. Pipe system according to claim 6, wherein the pipe and the additional pipe enclose an angle defined by the sleeve. 8. Pipe system as claimed in claim 5, 6, or 7, wherein the sleeve forms at least one of the connections of: an end piece or closure piece, a continuous connection, a knee connection, a T-connection, a cross connection, etc. . 9. Method for connecting a coupling piece according to at least one of the preceding claims 1-4 and including at least one thermoplastic plastic pipe, comprising heating the inside and the outside of the pipe, and the inside of the sleeve and the flange, combining the conduit and the sleeve, and allowing the assembly thus obtained to cool down fused. Method according to claim 9, comprising deforming the sleeve under pressure on and around the pipe, without heating. 11. Device for connecting a coupling piece according to at least one of the preceding claims 1-4 and 25, comprising at least one thermoplastic plastic, comprising means for heating the inside and the outside of the line, and means for heating from the inside of the sleeve and the flange to form a connection between them after joining the pipe and the sleeve and after allowing the assembly thus obtained to cool down.