AU652541B2

AU652541B2 - A concrete pipe with a lining resistant to corrosion and with fitting connecting members and furthermore with sealing means integrated in the terminal parts of the pipe

Info

Publication number: AU652541B2
Application number: AU64963/90A
Authority: AU
Inventors: Georg Fasel
Original assignee: Individual
Current assignee: Individual
Priority date: 1989-11-03
Filing date: 1990-10-24
Publication date: 1994-09-01
Anticipated expiration: 2010-10-24
Also published as: DK0426147T3; EP0426147A2; EP0426147B1; EP0426147A3; GR3018822T3; DE4034953A1; DE4034953C2; HRP940594A2; ES2081896T3; ATE133485T1; CA2029144A1; DE8913022U1; AU6496390A; DE59010086D1

Abstract

In concrete pipes 2, having a corrosion-resistant inner lining, said lining is a plastic pipe 9 which is resistant to acidic sewage and whose one end part is constructed as a pipe tip end part 3, the other end being constructed as a pipe sleeve end part 4 for holding the tip end part 3, the plastic pipe projecting on its inner side in each case over the concrete pipe or the concrete surround 2, with an overhang 5, as an adjustment and connection aid for the perfect joining of the individual pipes to one another, it being possible to support their ends 9 on a circumferential step 8 on the inner wall 6 of the respectively following plastic pipe. Arranged between the plastic pipe sleeve end 12 and the step 8, in the inner wall 6, is a circumferential groove in which an annular seal 14, consisting for example of latex and the like, is mounted. Furthermore, annular seals 15 are also provided to ensure perfect sealing, in each case between the outer concrete walls 23 and the inner concrete walls 24. <IMAGE>

Description

652541 COMMONWEALTH OF AUSTRALIA PATENTS ACT 1952 COMPLETE SPECIFICATION NAME ADDRESS OF APPLICANT: Ulrike Fasel Gotthardsweg 17 D 5439 Nisterau 2 S. GCermany NAME(S) OF INVENTOR(S): Georg Fasel ADDRESS FOR SERVICE: DAVIES COLLISON Patent Attorneys 1 Little Collins Street, Melbourne, 3000.

COMPLETE SPECIFICATION FOR THE INVENTION ENTITLED: A concrete pipe with a lining resistant to corrosion and with fitting connecting members and furthermore with sealing means integrated in the terminal parts of the pipe The following statement is a full description of this invention, including the best method of performing it known to me/us:la The invention relates to a concrete pine with a corrosion resistant lining.

Pipes made of plastic and of concrete are presently on the market. In the first case the pipes are usually made entirely made of drawn plastic while pipes made of concrete are generally produced in a vertical mold with a sliding core. Drain systems are to a large extent built up using such pipes. The requirements they .have to meet in order not to present an environmental hazard are becoming more and more exacting so that it is hardly possible to meet such requirements at the present time. This is more 15 particularly due to the fact that the pipes corrode owing to the action of aggressive, acidic waste water and thus develop leaks and fail. Such corrosion however means that individual pipes constantly have to be replaced and finally all the pipes of a system have to be replaced, this being more often the case at 20 present than was the case a few years ago. In order to avoid such disadvantages there has already been a proposal to provide a concrete pipe combined with a plastic pipe. Since such pipes are normally laid like concrete pipes with the spigot end projecting -2into the socket end of the next following pipe so as to provide a rigid joining, such spigot end are very likely to be damaged. Furthermore, owing to their rigid jointing means and owing to lack of sufficient means for allowing for the possibility of thermal expansion of the plastic parts in relation tot he concrete part and the concrete pars in relation to the concrete parts on fitting the pipes together cracks are due to stress in the concrete material and/or bursting of the inserted pipe ends is likely so that such pipe parts are damaged for this reason and they have to be replaced by new pipes.

A preferred object of the present invention is to provide concrete pipes with a corrosion-resistant lining for drain purposes Which as compared with conventional piping are able to be made with lower material and production costs and are furthermore able to resist very aggressive, acidic sewage or waste water. A further preferred object of the invention if; to provide such a pipe with a connecting means ensuring a highly satisfactory action as regard sealing off the bore of the pie from the surroundings. A still further preferred aim of the invention is to provide a simple connection between a system made up of the novel pipes and a pre-existing pipe system, consisting for instance of plastic or concrete, cast iron, asbestos-cement material and the like so that strong and completely sealed joints are produced.

According to a first aspect of the present invention there is provided a pipe with a corrosion resistant lining arranged for connection. with a similar pipe, said pipe having socket means formed at a first end and spgo means formed at a second end, said corrosion resistant lining having a projecting part formed at said second :end and abutment means formed adjacent said first end, said abutment means extending radially into the interior of said pipe for a distance substantially equal to the thickness of the projecting part, and seal receiving means formed in the corrosion resistant lining between the abutment means and said first end, said pipe being arranged to be connected to an adjacent similar pipe by insertion of the spigot means of said adjacent pipe into the socket means of said pipe and insertion of the projecting part of said adjacent pipe into the interior of said pipe, said projecting part of said adjacent pipe being arranged to abut against the abutment means of said pipe, said seal receiving means of said pipe being arranged to receive a first seal means which is arranged to provide a seal between the projecting part of said Q1 940617,p:\oper\kay,61963-90.145,2 V-'7 I -3adjacent part and the corrosion resistant lining of said pipe, the connection between said pipes being such as to allow for movement resulting from thermally induced stresses in the pipes and to maintain good sealing between the corrosion resistant linings of said pipes.

According to a second aspect of the present invention there is provided a method of producing a pipe with a corrosion resistant lining as claimed in any one of the preceding claims comprising the steps of providing a corrosion resistant pipe with such a length that it has a projecting part projecting past an outwardly moved axial core of a conventional pipe making machine, placing a first end of the corrosion resistant pipe onto the core of in the pipe making machine, placing a pipe mold over the length of the core such that a space is formed between the pipe mold and the corrosion resistant pipe, said space having a thickness equal to the thickness of the pipe to be molded, covering the opening of the corrosion resistant pipe, pouring mold material into the space until it reaches the level of the core so that after drying of the mold material a pipe formed with a socket means is provided and the projecting part is left without any mold material around it.

An embodiment of the invention will now be described by way of example only with reference to the accompanying drawings in which: Figure 1 shows a plurality of laid pipes diagrammatically in partial section.

Figure 2 is a view of part of a piece of pipe forming part of a connection between two laid pipes as seen in perspective.

Figure 3 is a view of a pipe joint between two 940617.p:\oper\ky,64963-90.145,3

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o 3 -4pipes in a smaller scale, in the case of which a concrete and plastic pipe is to be seen with a length of plastic pipe projecting from it.

Figure 4 is a diagrammatic representation of the method steps involved in the production of a concrete pipe provided with a plastic lining and having such .plastic pipe projecting at one end.

Figure 1 shows a plastic pipe 1 provided with a concrete pipeeaszig 2, the plastic pipe serving as a corrosion resistant, liquid-tight lining of the concrete pipe one end of same being the form of a pipe spigot end part 3 and the other end being in the form of a pipe socket end part 4, and with the end parts 3 and 4 the concrete pipes are joined together. In this respect the pipe spigot end part 3 of the one pipe is inserted into the pipe socket end part,of the other pipe. As a guiding means for aiding insertion there is a projecting part 5 of the plastic pipe 1 projecting past the concrete pipe 2 and, respectively, its concrete casing 2 at the pipe spigot end part. In order secure the two pipes to be joined together the inner wall face 6 of the pipy socket end part 4 is provided with a circumferential ledge 8 projecting into the interior 7 of the pipe and the end face 9 of the projecting part 5 of the plastic pipe is able to be brought into engagement with the ledge. It is convenient if the end face 9 and the ledge 8 extend in the direction of flow of the sewage water to be conveyed by the pipe in order to avoid back pressure if dirt should collect adjacent to the gap. In this respect the height of the ledge 8 is generally equal to the wall thickness 11 of the plastic pipe 1 forming the projecting part. Furthermore in the pipe socket end part 4 of the plastic pipe there is, between the plastic pipe socket end and the ledge 8, a groove 13 opening into the interior 7 of the pipe and extending in the circumferential direction, such groove serving to receive an annular and preferably flat seal of a natural or synthetic flexible material, as for example a latex. The flat annular form is to be preferred to a round one since it will be seated in a fixed and stable manner in the groove 13 which is preferably of rectangular in cross section. The projecting part 5, which is able to be inserted into the pipe socket end part, has to be so long in this connection that on the one hand it covers the circumferential groove its seal 14 and on the other hand the end face 9 is able to bear against the C. ledge 8, see figure 2. It is furthermore to be noted that the 10 concrete pipe members have a circumferentially extending, annular seal 15 of flexible material between the concrete pipe spigot end part 3 on the outside 23 and the concrete socket end part 4 on the inner side at 24. The plastic pipes may in a suitable form and size be inserted into the concrete pipe with a suitable inner form in relation to the plastic pipe with a suitable size. It is an advantage if the composite pipe is manufactured with all its .000 features as described above in a conventional pipe casting or C4*C° o molding machine 16, after the manufacture of the plastic pipe able to be used as the core. For this purpose the concrete pipe with the socket end part directed downwards is moved onto the axially extending and vertically movable core 17 of the pipe molding machine so that the pipe takes up a concentric position on the *core. In this respect the plastic pipe has to be so long that it projects past the core of the pipe making machine in its outwardly moved terminal setting by the preset projecting part 5. After introduction of the core into the opening of the pipe 19 the latter is covered over by a lid 20 in order in the ensuing coating process of thr. concrete pipe with a concrete mix to ensure that none of the concrete material finds its way into the interior of the pipe.

Following this a pipe mold 18 of steel is introduced into the length of the core of the pipe making machine with a clearance in the desired thickness of concrete pipe body to be molded or cast and also pushed downwards and after being pushed on the pipe mouth is covered over. Then the space '12 between the pushed on plastic -6pipe 2 and the inner wall face of the steel mold 18 concrete 22 is filled in downwards while shaking until the level of the core end 21 is reached. After drying of the molding and shifting it out of the molding machine there will be a concrete-plastic pipe, in the case of which a plastic pipe end part without any concrete casing projects out of the end in the form of the projecting part 5 of the plastic pipe, see figure 4.

The composite pipes able to be produced in accordance with the invention only need a small amount of seals 14 and sealing means 15 to provide not only a very satisfactory sealing action to prevent the leakage of liquid out of the pipe, but also, owing to the projecting pipe at every pipe end there is also an overlapping and direction connection without intermediate parts of the concrete pipe plastic composite pipes with each other. The flexible sealing and gaskefting means 14 and 15 used in this respect means that there is considerable freedom to move in the axial and lateral directions for the expansion and contraction of the pipes at their joints and also to allow for relative motion between the concrete pipe and the plastic coating so that any stresses due to the effects of heat or variations in temperature, which might lead to cracking or even splitting of the pipes are allowed for. Furthermore the intermediate connecting members needed for joining and sealing of the connected parts where the ends of the pipes are adjacent to each other, as for instance in the case of a known composite 25 concrete plastic pipe, are now no longer required owing to the direct pipe joint with an overlap.

Throughout this specification and the claims which follows, unless the context requires otherwise, the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.

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Claims

1. A pipe with a corrosion resistant lining arranged for connection with a similar pipe, said pipe having socket means formed at a first end and spigot means formed at a second end, said corrosion resistant lining having a projecting part formed at said second end and abutment means formed adjacent said first end, said abutment means extending radially into the interior of said pipe for a distance substantially equal to the thickness of the projecting part, and seal receiving means formed in the corrosion resistant lining between the abutment means and said first end, said pipe being arranged to be connected to an adjacent similar pipe by insertion of the spigot means of said adjacent pipe into the socket means of said pipe and insertion of the projecting part of said adjacent pipe into the interior of said pipe, said projecting part of said adjacent pipe being arranged to abut against the abutment means of said pipe, said seal receiving means of said pipe being arranged to receive a first seal means which is arranged to provide a seal between the projecting part of said adjacent part and the corrosion resistant lining of said pipe, the connection between said pipes being such as to allow for movement resulting from thermally induced stresses in the pipes and to maintain good sealing between the corrosion resistant linings of said pipes.

2. A pipe according to claim 1 further comprising second seal means arranged to provide a seal between the spigot means of said adjacent pipe and the socket means of said pipe. '25 3. A pipe according to claim 1 or claim 2 wherein the seal receiving means comprises a circumferential groove and the first seal means comprises an elastomeric sealing ring.

4. A pipe according to claim 3 wherein the groove has a rectangular cross- "30 section and the sealing ring has a substantially flat external form so as to enable the sealing ring to be seated in the groove. 9 tKi 17,p: \opcr\kay,6A963 90.145,7 -8- A pipe according to any one of the preceding claims which is made from concrete.

6. A pipe according to any one of the preceding claims wherein the corrosion resistant lining is made from a plastics material.

7. A method of producing a pipe with a corrosion resistant lining as claimed in any one of the preceding claims comprising the steps of providing a corrosion resistant pipe with such a length that it has a projecting part projecting past an outwardly moved axial core of a conventional pipe making machine, placing a first end of the corrosion resistant pipe onto the core of in the pipe making machine, placing a pipe mold over the length of the core such that a space is formed between the pipe mold and the corrosion resistant pipe, said space having a thickness equal to the thickness of the pipe to be molded, covering the opening of the corrosion resistant pipe, pouring mold material into the space until it reaches the level of the core so that after drying of the mold material a pipe formed with a socket means is provided and the projecting part is left without any mold material around it.

8. A pipe or a method of producing the same substantially as hereinbefore described with reference to the accompanying drawings. 9 S Dated this 17th day of June, 1994 D25 ULRIKE FASEL By his Patent Attorneys DAVIES COLLISON CAVE *J o oo *o• *o 9406 17,p:\opcrkay,6-'963-90.145,8