NL1040678C2

NL1040678C2 - System for providing at least a part of a fluid connection between a supply pipeline positioned in the ground and a branched-off pipeline part and use of such a system.

Info

Publication number: NL1040678C2
Application number: NL1040678A
Authority: NL
Inventors: Marrie Lamberts
Original assignee: Wavin Bv
Priority date: 2014-02-19
Filing date: 2014-02-19
Publication date: 2015-08-25

Description

System for providing at least a part of a fluid connection between a supply pipeline positioned in the ground and a branched-off pipeline part and use of such a system

The invention is related to a system for providing at least a part of a fluid connection between a supply pipeline positioned in the ground and a branched-off pipeline part situated downstream of the supply pipeline and having a fixed position. Usually, the branched-off pipeline part has a fixed position relative to a construction. The invention is also related to use of such a system.

In constructions, such as buildings, factories, industrial plants etc, gas may be used for heating, raising the temperature to carry out thermally activated processes, and/or facilitating chemical reactions. The gas is usually supplied to the relevant position via a main pipeline positioned in the ground from which one or more pipelines branch off to the various relevant constructions where the gas is needed. Downstream a branched-off pipeline, the branched-off pipeline will have a fixed position relative to a construction, such as a foundation of a building, factory or industrial site. This fixed position is often a consequence of a sealed-off penetration through a foundation wall. A problem occurs when ground around a foundation of a construction sinks downwards. It is then possible that a part of the branched-off pipeline sinks down with the ground in which it has been embedded and a part of the branched-off pipeline which has a fixed position relative to the construction remains in that fixed position. If the branched-off pipeline were to break, gas would leak, and potentially a gas explosion could occur. This problem may occur in areas where the groundwater level can be high and/or fluctuate much over a period of time. This problem may also occur where due to drilling for gas or oil, cavities were generated in the soil.

Where such a displacement could occur, ideally "relaxation elements" are incorporated to accommodate for the relative displacement of the parts of the branched-off pipeline. A known relaxation element comprises a flexible pipeline having at each end a coupling element and between these coupling elements a U-shaped pipeline part. When due to sinking of the ground the distance between the coupling elements becomes larger, then the legs of the U-shaped element spread further out to accommodate for the growing distance between the coupling elements . A disadvantage of this relaxation element is that the positioning, i.e. the direction of the U-shaped element may be arbitrary, in that the workman installing the relaxation element has some freedom in the positioning of the U-shaped element, leading to, for instance an orientation upwards, downwards, sideways, or under a prescribed angle with a vertical direction. Even when the orientation of the U-shaped part of the pipeline is adhered to by the workman, then it is still unlikely that the relaxation element is always in a condition for optimally responding for each and every direction into which the supply pipeline could move away. Further, the relaxation elements occupy a relatively large part of the ground. Given that the orientation of the U-shaped part may hot-always be the same, a relatively large part of the ground is potentially occupied by the relaxation element, so that for planning purposes of other cables, such as for instance optical fiber cables for data transport, less space is available.

It is an object of the invention to provide a system that will address at least one of the above-mentioned problems.

The object of the invention is achieved by providing a system for providing at least a part of a fluid connection between a supply pipeline positioned in the ground and a branched-off pipeline part situated downstream of the supply pipeline and having a fixed position. The system comprises a flexible pipeline which is at least partially in the shape of a spiral for placement as part of the fluid connection between the supply pipeline and the branched-off pipeline.

Having at least a part of the flexible pipeline in the shape of a spiral has the advantage that the flexible pipeline will more likely be in a position to accommodate for different directions (sideways and downwards) of sinking away of the ground and therewith the sinking of an upstream part of the branched-off pipeline that will sink, away with that ground. A supply pipeline may in this context also be an upstream part of the branched-off pipeline of which a downstream part is fixed.

Further, the flexible pipeline can due to its shape be installed in a very compact way without jeopardizing the length of the maximum displacement for which it can accommodate when an upstream part of the branched-off pipeline sinks away with the ground, and another part, more downstream the branched-off pipeline, maintains its fixed position with respect to a construction.

In an embodiment of a system according to the invention, the flexible pipeline is in a pre-torsioned condition which will at least partly be undone on expanding of the spiral in an axial direction thereof. The pre-torsioned condition is upon expanding of the spiral in an axial direction thereof at least partly undone as the expanding of the spiral in an axial direction thereof coincides with a torsion in an opposite direction. This embodiment has the advantage that a possible and undesirable onset of kinking of the flexible pipeline is addressed. The pre-torsioned condition ensures that the conditions which apply for kinking to occur are, for an expansion of the spiral in an axial direction, not reached as early as would be the case for a flexible pipeline which had not been put in a pre-torsioned condition.

In a system according to the invention, the flexible pipeline is kept in the shape of a spiral by one or more holders which will lose their hold upon exceeding a predetermined expansion force of the spiral in axial direction thereof. Advantageously, it is possible to use a hose-type of pipeline, and put this in the shape of a spiral, for instance by temporarily coiling it around a mandrel, and then applying simple and straightforward holders such as strips of tape which can easily be torn.

In an embodiment of a system according to the invention, the flexible pipeline is at least partially kept in the shape of a spiral by material properties of the flexible pipeline. This means that any holders, if at all, do not need to be too strong to keep the flexible pipeline in the shape of a spiral and that, consequently, the responsiveness of the system upon a relatively small displacement would already lead to a situation in which the holders lose their hold over the shape of the spiral or the relative position of the windings of the spiral.

In an embodiment of a system according to the invention, the system is provided with a bracket for holding the flexible pipeline and mounting the flexible pipeline in a predetermined position. Advantageously, the installation can be done quickly, accurately and consistently so that the predictability of the response of the flexible pipeline will be high. Such mounting can for instance be against an outer part of a foundation, close to the point where the branched-off pipeline penetrates the foundation for entering a construction. A predetermined position is preferably such that the axis of the spiral is oriented in a vertical direction. This most easily facilitates for a displacement between the respective parts of the branched-off pipeline as will most likely occur when ground sinks.

In an embodiment of a system according to the invention, at least one of the ends of the flexible pipeline is oriented in a direction which is transverse to the axial direction of the spiral. Advantageously, gas flowing in that end, or flowing out of that end, will not experience a huge resistance so that the pressure drop due to the presence of the flexible pipeline will be minimal.

In an embodiment of a system according to the invention, at least one of the ends of the flexible pipeline is oriented in a direction that is parallel to the axial direction of the spiral. In such an embodiment, on that end there will hardly, if at all, be any sideways acting forces on that end when the spiral expands in its axial direction. A coupling that will tighten upon further tensioning, will then be optimally acting in response to the circumstances.

In an embodiment of a system according to the invention, the ends of the flexible pipeline are tangentially oriented with respect to the spiral. This facilitates easy production of the flexible pipeline in the shape of that embodiment.

In an embodiment of a system according to the invention, the ends of the flexible pipeline are oriented in directions which are parallel to each other.

Preferably, the ends of the flexible pipeline depart at the same circumferential position from the spiral into a tangential direction. In such an embodiment, the planning of the positioning of the branched-off pipeline upstream and the part of the branched-off pipeline downstream and fixed relative to the construction can take place in a straightforward way without having to take into account the dimensions of a system for responding to a relative displacement of these parts of the branched-off pipeline. Furthermore, such an embodiment can also be used for installation at already existing constructions where gas supply lines are already in place and enter these constructions.

In an embodiment of a system according to the invention, at least one end of the flexible pipeline is provided with a coupling element. Preferably, the coupling element tightens the coupling upon tensioning. Such a coupling will respond optimally when the occasion of a relative displacement of the respective parts of the branched-off pipeline will take place. Ideally, the coupling elements are of the type "plug and play", so that installation errors are hardly possible, if at all.

In an embodiment of a system according to the invention, the spiral has at least one winding, preferably two and even more, preferably three or four. Advantageously, with more windings, the length of the relative displacement which the flexible pipeline can accommodate will be higher. Further, as it is likely that the displacement will equally be distributed over the relative displacement of the various windings, the likelihood of any undesired deformation such as kinking, will be minimal.

The invention also relates to the use of a system as described above.

The invention, and various embodiments thereof, will further be explained on the basis of examples, with reference made to a drawing, in which:

Fig. 1 shows schematically a top view of an embodiment of a system according to the invention;

Fig. 2 shows schematically a side view of the embodiment shown in Fig. 1; and

Fig. 3 shows schematically a front view of the embodiment shown in Fig. 1 and Fig. 2.

In the drawing, like parts have like references.

The drawing shows an embodiment of a system for providing at least a part of a fluid connection between a supply pipeline positioned in the ground and a branched-off pipeline part situated downstream of the supply pipeline and having a fixed position. The system comprises a flexible pipeline 1. A top view of the embodiment is shown in Fig. 1.

As can more easily be seen from Figs. 2 and 3, at least partially the flexible pipeline 1 is in the shape of a spiral, suitable for placement as part of the fluid connection between the supply pipeline and the branched-off pipeline part. The flexible pipeline 1 is preferably partially kept in the shape of a spiral by material properties of the flexible pipeline 1. The flexible pipeline 1 may be machine-formed, on the basis of winding a gas pipe over a mandrel, heating this gas pipe whilst keeping it in the coiled shape over the mandrel, and subsequently cooling the gas pipe. The gas pipe may be a standard PE 80 gas pipe. The flexible pipeline remains flexible in that an extension of the spiral in an axial direction thereof remains possible. The production of such a flexible pipeline is for a person skilled in the art doable on the basis of standard production methods which are in itself well-known.

The system may further comprise a bracket 2 for holding the flexible pipeline and mounting the flexible pipeline in a predetermined position. As can be seen in Fig. 1, bracket 2 is essentially U-shaped having a back 4 and two holding arms 5. The system may further be provided with fixators 6, for fixing a part of the flexible pipeline 1 to the holding arms 5 of the bracket 2. Suitable fixators 6 are well-known in the art. The holding arms 5 and the fixators 6 are seen to hold the flexible pipeline at the top and on the inside of the spiral. The bracket may be formed on the basis of a sheet of steel, ideally provided with a zink coating to allow for use outside a construction and exposure to atmospheric weather conditions. In the example shown in Fig. 3, two holes 3 are shown for fixation of the bracket 2 against, for instance, a foundation wall.

The predetermined position in which the flexible pipeline 1 will be mounted is preferably such that the axes of the spirals are oriented in a vertical direction. In the embodiment shown, at least one of the ends 7 of the flexible pipeline 1 is oriented in a direction that is transverse to the axial direction of the spiral. In fact, as shown, and in accordance with a preference, both ends 7 of the flexible pipeline 1 are oriented in a direction that is transverse to the axial direction of the spiral. However, it is not inconceivable that at least one of the ends 7 of the flexible pipeline 1 is oriented in a direction that is parallel to the axial direction of the spiral. From Fig. 1 it can easily be seen that the ends 7 of the flexible pipeline 1 are in the embodiment shown also tangentially oriented with respect to the spiral. Furthermore, in accordance with a further preference, the ends of the flexible pipeline 7 are also oriented in directions which are parallel to each other.

Even more preferably, the ends 7 of the flexible pipeline 1 depart at the same circumferential position from the spiral into a tangential direction. However, it is not inconceivable that the ends 7 of the flexible pipeline 1 depart at opposite circumferential positions from the spiral into a tangential direction.

It is further possible that the flexible pipe is in a pre-torsioned condition which will at least partly be undone on expanding of the spiral in an axial direction thereof.

Although not shown in the drawing, it is also possible that the flexible pipeline 1 is kept in the shape of a spiral by one or more holders which lose their hold upon exceeding a predetermined expansion force of the spiral in axial direction thereof.

An embodiment of a system according to the invention further comprises at least one coupling element (not shown) for placement at an end 7 of the flexible pipeline 1 and for coupling to another part of the branched-off pipeline. A special coupling element may be needed for particular purposes. However, in general, it is preferred that the coupling element tightens the coupling upon tensioning. That is when a pulling force is exerted on an end 7 of the flexible pipeline 1, then the respective coupling element (not shown) coupling that end 7 to another pipe end, would tighten the coupling.

The drawing shows three dimensions, namely a diameter d of the windings, a width b of the back of the bracket 4 and h which corresponds to the height of the flexible pipeline 1, measured in an axial direction of the spiral.

For a PE 8 0 gas pipe, having a diameter of 32 mm, the diameter d of the winding will ideally be around 400 mm, the back of the bracket b will then be about 350 mm, and the height will be about 85 mm. For a diameter of 40 mm of the gas pipe PE 80, d may be about 50 mm and b be about 4 50 mm. The height h will then be about 100 mm. For a gas pipe PE 80 having a diameter of 50 mm, the diameter d of a winding will be about 650 mm, the back of the bracket will have a width b of about 500 mm, and the height of the flexible pipeline measured in axial direction of the spiral will be about 120 mm. For each of these dimensions, the flexible pipeline can easily accommodate an extra displacement between the ends 7 of the flexible pipeline in axial direction in the order of 80 cm. That is, when the ground sinks 80 cm down relative to the point where a downstream branched-off pipeline is fixed into, for instance, a foundation wall, the system can easily cope without causing leakage of gas etc. Furthermore, the very same flexible pipeline 1 does not need to be replaced when the ground has been repaired, i.e. when the system is put back in the position it had before the ground sank away.

It will be clear for a person skilled in the art that a larger number of windings will result in a larger displacement between the ends 7 which can be handled by the system without any problems of concern. On the other hand, the difference in axial direction between the ends 7 of the flexible pipeline 1 in unstretched condition of the spiral, will then be larger, so that the system may then not so easily be installable in existing pipeline parts without using additional elements for optimizing the fit.

The system has a low number of parts and each of the parts is in itself well-known and easy to handle. This minimizes the probability of installation errors. The system can be used at the outside of a foundation so that any gas leakage, if at all, will not lead to an explosion inside the construction.

The use of a system as described above, as at least a part of a fluid connection between a supply pipeline positioned in the ground and a branched-off pipeline part situated downstream of the supply pipeline and having a fixed position, is relatively straightforward. A relatively small hole needs to be dug for installing this system. For the 32 mm diameter gas pipe, the hole needs to be about 0.5 m x 0.5 m with a depth of about 0.3 m, measured from the position of the branched-off pipeline part that is fixed to the foundation. For the 40 mm diameter gas pipe, the hole needs to have overall dimensions of 0.6 mx 0.6 m and again a depth of 0.3 m below the branched-off pipeline that is fixed to the foundation. For a 50 mm diameter gas pipe, the lateral dimensions are ideally 0.8 m x 0.8 m and the depth is ideally 0.4 m below the branched-off pipeline that is fixed to the foundation. A suitable length of a part of the existing branched-off pipeline needs to be removed and coupling elements need to be placed on the ends of the remaining pipeline parts. Holes need to be drilled so as to allow for fixation of the bracket 4 in such a way that the ends 7 of the flexible pipeline 1 can easily be plugged into the respective coupling elements. After installation, the hole may be filled up with sand/soil, and the job is done. For each and every embodiment discussed above, the pressure drop will be much lower than 1 mbar.

The invention is not limited to the embodiment shown and discussed above. For a particular situation it may be recommendable to have additional coupling elements, for instance those having a 90° bend. Alternatively, or additionally, the ends 7 of the flexible pipeline may depart from the spiral shape at different positions and/or at different angles. As indicated above, the orientation of the spiral may in particular circumstances need to be different than outlined above. Each and every modification along these line is understood to fall within the framework of the invention as defined by the appending claims.

Claims

A system for providing at least a portion of a fluid communication between a supply pipeline positioned in the ground and a branched pipeline portion located downstream of the supply pipeline and having a fixed position, the system having a flexible pipeline provided is at least partially in the form of a coil for placement as part of the fluid communication between the supply pipeline and the branched-off pipeline part.

The system of claim 1, wherein the flexible pipeline is in a pre-twisted state that will be undone at least in part upon expansion of the coil in an axial direction thereof.

A system according to claim 1 or 2, wherein the flexible pipe is held in the form of a spiral by one or more holders that will lose their grip when transcending a predetermined expansion force of the spiral in an axial direction thereof.

System as claimed in any of the foregoing claims, wherein the flexible pipeline is at least partially held in the form of a spiral by material properties of the flexible pipeline.

A system according to any one of the preceding claims, wherein the system is provided with a support for holding the flexible pipeline and fixing the flexible pipeline in a predetermined position.

The system of claim 5, wherein the predetermined position is such that the axis of the coil is oriented in a vertical direction.

A system according to any preceding claim, wherein at least one of the ends of the flexible pipeline is oriented in a direction that is transverse to the axial direction of the coil.

A system according to any one of the preceding claims, wherein at least one of the ends of the flexible pipeline is oriented in a direction parallel to the axial direction of the coil.

The system of any one of claims 1-7, wherein the ends of the flexible pipeline are tangentially oriented with respect to the coil.

System as claimed in any of the foregoing claims, wherein the ends of the flexible pipeline are oriented in directions that are parallel to each other.

The system of claim 10, wherein the ends of the flexible pipeline at the same circumferential position deviate from the coil in a tangential direction.

The system of claim 10, wherein the ends of the flexible pipeline at the opposite circumferential positions deviate from the coil in a tangential direction.

System as claimed in any of the foregoing claims, wherein at least one end of the flexible pipeline is provided with a coupling element.

A system according to claim 13, wherein the coupling element makes the coupling more tight when tightening.

A system according to any one of the preceding claims, wherein the coil has at least one winding, preferably 2, with 3 or 4 being even more preferred.

Use of a system according to any one of the preceding claims, as at least a part of a fluid connection between a supply pipeline positioned in the ground and a branched pipeline part downstream of the supply pipeline having a fixed position.