FR2787552A1 - TUBE, PARTICULARLY WOUND TUBE IN PLASTIC MATERIAL, PROVIDED WITH A LEAK COLLECTION CHANNEL - Google Patents

Abstract

The invention relates to a tube (1), in particular a coiled plastic tube, with in the tube wall (2) a leakage collecting channel (4) which extends in a helix and forms turns of the channel. collection of leaks. The leakage collecting channel (4) is subjected to positive pressure and has at least one leakage detection device arranged in the form of a pressure variation detector. At least a first connecting channel (6) is arranged in the tube wall (2); the connecting channel extends over the entire length of the tube, substantially parallel to the axis (5) of the tube, and interconnects the turns of the leakage collecting channel (3). This makes it possible to evacuate the liquid from leak present in the leak collecting channel, in particular after repairing a leak and keeping the leak detection device in working condition.

Description

Tube, in particular plastic wound tube, provided with a channel

  The invention relates to a tube, in particular a wound plastic tube, comprising a leak collection channel which extends in a helix in the wall of the tube by forming turns of the leak collection channel, the leakage collection channel being subjected to positive pressure and comprising at least one leakage detection device arranged in the form

  pressure fluctuation detector.

  Coiled tubes of this type are produced, for example, from hollow profiles, produced according to a plastic extrusion process. Hollow profiles have a cross section

  rectangular or square exterior. The coiled tube is obtained by winding

  lant helical, tightening against each other, hollow profiles, the cavity with a round, regular cross-section, hollow profiles forming the leakage collecting channel. The coiled tubes arranged vertically and provided with a bottom can be used as containers for liquids (see document DE 44 10 593). In addition, the coiled tubes arranged horizontally or sloping are used as conduits for

  liquid, for example as waste water pipes.

  Coiled tubes are characterized by their high stability and the possibility of detecting leaks by simple means. A crack that propagates in the wall of the tube, from the inner surface or the outer surface of the latter, necessarily cuts the helical leak collection channel. The pressure drop which then occurs inside the leak collection channel is detected by the pressure variation detector. In principle, it is also possible, within the framework of the present invention, to apply a negative pressure in the channel of

collection of leaks.

  So far, the known coiled tubes have given satisfaction in practice. However, in particular when the coiled tube is arranged horizontally or when it is slightly inclined, the leakage liquid present in the leakage collecting channel is only very difficult to remove.

  once the leak is closed, because the liquid collects in the spi-

  of the leakage collection channel, in the low point area of the tube or channel. Even when positive pressure is applied to the leak collecting channel, it is highly likely, in the event of a problem, that liquid enters from outside or inside the leak collecting channel. Admittedly, this first of all has no consequence with regard to the detection of the leak, since the leak detection device reacts to pressure variations inside the leak collecting channel, but it is it is practically impossible to return the leak detection device to service after the leak has been repaired. Indeed, there remains in the leakage collecting channel a liquid / air mixture which, on

  the plan to continue monitoring leaks, creates conditions

  difficult to control, given that the air is compressible and

  that the liquid is generally not compressible. Reliable surveillance

  ble leakage is hardly possible then with the leakage monitoring devices arranged in the form of pressure change detectors. Furthermore, with the long helical leak collection channel in known coiled tubes, pressure balancing is relatively slow. When manufacturing coiled tubes or when connecting multiple coiled tubes, tightening or even complete obstructions of the leakage collection channel may occur. In this case also, it is no longer possible to obtain reliable monitoring, since the pressure variations in a part of the leakage collection channel are not

  no longer detected by the pressure variation detector, sometimes very far

embarrassed.

  The object of the present invention is to provide a tube, in particular

  tie a coiled tube, of the type described in the introduction, which has a cons-

  simple and stable construction and allows reliable monitoring of leaks,

  even after repairing the coiled tube following a leak.

  To achieve this object, the invention teaches to have in the tube wall, at least a first connecting channel which extends over the entire length of the tube, substantially parallel to the axis of the tube, and connects the

  to each other the spiers of the leakage collecting channel.

  The invention is based on the observation that the above-mentioned drawbacks of known rolled tubes can be avoided in a surprisingly simple manner by providing a connecting channel which forms a transverse communication between the different

  leakage channel spiers. When the tube wound according to the invention

  tion is arranged horizontally or is slightly inclined, the first connecting channel which connects the turns of the leakage collecting channel acts as a flow channel in the region of the low point of the tube. If liquid enters the leak collection channel following a leak, said liquid flows through the evacuation channel located at the lowest point

  or is sucked. In this way, no more liquid remains in the col-

  reading of leaks after repair of the leak and the device for detecting

  leaks continue to operate without problems.

  This provides a particularly simple and reliable way

  ble of a possibility of repair after damage. Even tighten-

  Leakage channel turns or obstructions in the area of the leakage channel turns have no effect on operation since

  thanks to the first link channel, there is a permanent communication

  direct connection between the turns of the leakage collection channel. In addition, the reaction time of the leak detection system is considerably reduced thanks to the connecting channel which connects the turns of the leak collecting channel. In principle, it is no longer essential to monitor an air column, the total length of which can be very large, given the helical winding of the leakage collecting channel. In fact, the

  leakage collection channel is a shortcut by which the fluctua-

  Air pressure is carried much faster. An operational problem during manufacture, during the extrusion of the plastic material or when welding the tubes wound on the

  site no longer results in a malfunction of the detection system

leaks.

  According to another recommendation of the invention, provision is made for

  lay in the region of the tube wall located opposite the first connecting channel, a second connecting channel which also extends substantially parallel to the axis and connects the turns of the collecting channel

  leaks. When the coiled tube is arranged horizontally or is weak-

  inclined, the second leakage collection channel is located in the region of the highest point of the container and serves as a ventilation channel. This avoids the appearance of a negative pressure at the level of the leakage collecting channel or of the flow channel during the flow or during the aspiration.

leaking liquid.

  Other important provisions of the invention are described in the following. According to a preferred embodiment at least the first

  channel connection is tangentially connected communicates tangentially-

  with the spiers of the leak collecting channel, in the outside region

  lower of these which is distant from the axis of the tube. Thus, when the coiled tube is arranged horizontally or when it is slightly inclined, the low point of the first connecting channel is always located at a level lower than the lowest point of the leak collecting channel so that all

  leakage liquid can safely flow out of the leakage collection channel

  tes to the first connecting channel or the flow channel. Canals

  connection can be made in the form of communication holes.

  Another aspect of the invention relates to a tube section formed of at least two tubes according to the invention, which are linked to each other at

  level of their front face. The tube walls have front faces

  tales outwardly conical and define at the junction between the front faces a peripheral groove with a V-section, into which the connecting channels open; the tube walls, in the region of the peripheral groove closest to the axis of the tube, are connected to each other by material or by gluing, preferably are welded to each other; at least in the area of the peripheral V-shaped groove, are

  surrounded by a sealing envelope which closes said peripheral groove

  that for example are surrounded by a sliding sleeve or a sleeve

  of connection which is linked to the tube walls by material or by bonding, pre-

  ference is welded. This makes it possible to obtain a reliable flow of the leakage liquid even in the case of a composite assembly, formed of several assembled tubes. In fact, the leakage liquid arrives via the turns of the leakage collecting channel in the connecting channel of a tube, which opens into the peripheral groove at the level of the assembly zone. From there, the liquid flows into the connecting channel of the neighboring tube and from there into the discharge pipe. It is no longer necessary to have communication between the

  helical leak collection channel of a section of tube and the collector channel

  reading of helical leaks from the contiguous tube section since there is a direct connection via the connection channels and the peripheral groove

  provides pressure balancing. The peripheral groove also allows

  compensation for mounting tolerances, perfect positioning of the tubes ensuring perfect leakage channels between them is no longer necessary. The result is a considerable simplification of the

  mounting and greater reliability in detecting leaks in sections

  tube lessons comprising several tubes. According to a prior arrangement

  geux of the invention, the peripheral V-shaped groove has, seen in section in the longitudinal direction of the tube, an opening angle oc included in

a range from 50 to 70.

  The invention is described below in detail with the aid of drawings which show only one embodiment. The drawings represent:

  Figure 1, part of a tube according to the invention in perspective view

tive and

  Figure 2, partially, a section in the longitudinal direction

  nale of the tube of a section of tube formed of two tubes which are linked one to

  the other at their frontal face.

  FIG. 1 represents a coiled tube 1 made of plastic, with a leakage collecting channel 4 which extends in a helix in the tube wall 2 by forming turns of the leakage collecting channel 3. The leakage collecting channel 4 is subjected to a positive pressure and comprises at least one leak detection device, arranged in the form of a detector

  pressure variations. The latter is not shown in the figures.

  In the tube wall 2 is arranged a first connecting channel 6 which extends over the entire length of the tube, parallel to the axis of the tube 5, and which interconnects the turns of the leakage collecting channel 3. In part of

  the tube wall 2 located opposite the first connecting channel 6 is improved

  swam a second connecting channel 7 which is parallel to the axis of the tube 5 and connects to each other the turns of the leakage collecting channel 3. The tube

  wrapped 1, in the embodiment, is slightly inclined relative to

  horizontal port. Thus the first connecting channel 6 serves as a flow channel 6, while the second connecting channel 7 serves as a ventilation channel 7. When, following a leak, leaking liquid enters one of the turns 3 of the channel for collecting leaks 4, said leaking liquid comes directly into the first connecting channel 6 arranged as a flow channel 6. The leaking liquid flows via this channel into a well in

  which opens the wound tube 1. The first connecting channel 6 communicates

  that tangentially with the turns of the leakage collecting channel 3, in the outer region thereof, distant from the axis 5. The same applies for

the second link channel 7.

  FIG. 2 represents a section of tube formed by two coiled tubes 1 which are linked to each other at their front face. It can be seen that the tube walls 2 have front faces 8 which are conical towards

  the outside and a peripheral groove 9 with a V section, seen in section following

  vant the axis of the tube, into which open the connecting channels 6, 7 is arranged in the assembly area between the front surfaces 8. The

  tube walls 2 are welded together in the region of the peri-groove

  spherical 9 close to the axis of the tube 5. In addition, the walls of tube 2, in the

  region of the peripheral groove 9, are surrounded by an envelope of

  sheave 10 which closes the peripheral groove 9. In the embodiment, the sealing envelope 10 is shaped as a sliding sleeve 10. The

  sliding sleeve 10 is welded to the tube walls 2.

  Figure 2 clearly shows that it is no longer essential that

  the leakage channel turns 3 of one of the coiled tubes I

  provide with the leakage channel turns 3 of the other coiled tube 1, since there is in all cases a communication between the

  leakage collection channels 4, via connection channels 6 and the peri-groove

  spherical 9. The leaking liquid can then flow via the connecting channel 6 of one of the wound tubes 1 into the peripheral groove 9 and from there into the connecting channel 6 of the other wound tube 1. O sees moreover that the peripheral groove in V 9, in section along the longitudinal axis of the tube, has

  an opening angle ox of approximately 50.

Claims (6)

  1. Tube (1), in particular plastic wound tube, comprising in the tube wall (2), a leak collecting channel (4) which extends in a helix by forming turns of the leak collecting channel (4), the   leakage collecting channel (4) being subjected to positive pressure and pre-   sensing at least one leak detection device arranged in the form of a pressure variation detector, characterized in that at least a first connecting channel (6) is arranged in the tube wall (2), which   connecting channel extends over the entire length of the tube, substantially parallel   parallel to the axis (5) of the tube, and connects together the col- lier channel turns leak reading (3).   2. Tube according to claim 1, characterized in that a   second connecting channel (7) which extends over the entire length of the tube, sensi-   parallel to the axis (5) of the tube, and interconnecting the turns of the leakage collecting channel (3) is arranged in the region of the tube wall   (2) remote from the first connecting channel (6).   3. Tube according to claim 1 or claim 2, character-   laughed at by the fact that at least the first connecting channel (6) is connected tan-   generally at the spiers of the leak collection channel (3), in the region   outside of these remote from the axis (5) of the tube.   4. Tube according to any one of claims 1 to 3, character-   laughed at by the fact that the connecting channels (6, 7) are shaped as communication holes. 5. Tube section formed by at least two tubes (1) according to a   any one of claims 1 to 4 linked to each other by their front face   tale, characterized in that the tube walls (2) have surfaces   these conical outer faces (8) and a peripheral groove (9) with a longitudinal V-shaped section into which the leakage channels open   (6, 7), by the fact that the tube walls (2) in the region of the peripheral groove   risk (9) closer to the tube axis (5) are linked by material or by adhesion   sif, preferably are welded, and that the tube walls (2) at least in the region of the peripheral V-groove (9) are surrounded by a sealing envelope (10) which closes the peripheral groove (9) , for example a sliding sleeve or a joining sleeve, which is bonded by material   or by gluing, preferably is welded, to the tube walls (2).   6. Section of tubes according to claim 8, characterized in that the peripheral V-shaped groove (9) in sectional view in the longitudinal direction of the tube, has an opening angle cc which is within a range from from 500 to 70. - -