Device for laying cables in ducts with lubricating capabilities

Abstract

A device for installing an elongated element (100) in a duct (200), comprising a pressure housing (10), the pressure housing (10) comprising: - inlet port (12), an outlet port (11) arranged to be connected to a duct (200) for introducing the elongated element (100) together with a driving fluid into the duct (200); a drive fluid chamber (20) arranged to receive a drive fluid supplied under pressure and to distribute the drive fluid in a duct (200) having an elongated element (100); a lubricant chamber (30) arranged to receive a lubricant and distribute the lubricant on the outer surface of the elongated element (100), the lubricant chamber (30) being located upstream of the drive fluid chamber (20); A device comprising: a pressure housing (10) arranged to receive pressurized drive fluid and comprising an upstream chamber (40) located upstream of a lubricant chamber (30).

Description

[Technical field]

[0001] The present invention relates to the field of dedicated machines for introducing cables into ducts, and in particular to the field of machines, apparatus and devices used at the inlet of a duct to assist and drive the introduction of a cable into the duct. [Background technology]

[0002] In the prior art it is known to use a driving fluid (gas or liquid) introduced at the inlet of the duct together with the cable in order to improve the conveyance of the cable into the duct and to increase the length of the cable that can be installed. In the prior art it is also known to use lubrication to improve the introduction of the cable, as disclosed in document US 7,992,685 (B2). However, the disclosed system can experience lubricant leakage and is complex, with several units that are installed before the cable is laid in the duct. Summary of the Invention

[0003] The present invention aims to address the above-mentioned shortcomings of the prior art and has as its first object to propose a device for laying elongated elements in ducts, which allows ease of use with reliable operation and reduces the risk of lubricant leakage.

[0004] To this end, a first aspect of the invention relates to a device for installing an elongated element in a duct, comprising a pressure housing, the pressure housing comprising: - an inlet port for receiving the elongated element; an outlet port arranged to be connected to a duct in order to introduce the elongated element into the duct together with the driving fluid; a drive fluid chamber arranged to receive a drive fluid supplied under pressure and to distribute the drive fluid in a duct having an elongated element; - a lubricant chamber arranged to receive a lubricant and distribute the lubricant on an outer surface of the elongated element, the lubricant chamber being located upstream (according to the movement of the elongated element) of the drive fluid chamber; The device is characterized in that the pressure housing is arranged to receive pressurized drive fluid and comprises an upstream chamber located upstream of the lubricant chamber (following the movement of the elongated element).

[0005] The pressure housing of the device according to the above embodiment comprises three separate chambers. From the inlet port to the outlet port (along the movement direction of the elongated element), the upstream chamber, the lubricant chamber and the drive fluid chamber are arranged in this order. In other words, the lubricant chamber is located between the upstream chamber and the drive fluid chamber, so that the lubricant leakage, even in the upstream direction, is kept in the pressure housing and the lubricant is mixed with the drive fluid (present in the upstream chamber and in the drive fluid chamber). Thus, there is no possibility of the lubricant leaking outside the pressure housing. In addition, since three chambers are provided and are formed by the pressure housing itself, the preparation work for installing the device and starting the installation work is reduced.

[0006] According to an embodiment, the pressure housing may comprise a fluid port for receiving the aforementioned pressurized drive fluid, which may be arranged to feed the pressurized drive fluid into the pressure housing downstream of the lubricant chamber. In other words, the pressurized drive fluid is provided into the pressure chamber at a location downstream (downstream with respect to the direction of movement of the elongated element) of the lubricant chamber. Thus, the drive fluid can enter directly into the duct without passing through or around the lubricant chamber, and the pressure housing remains compact and / or has no bypass or through channel to convey the drive fluid from a point located upstream of the lubricant chamber to a point located downstream of the lubricant chamber.

[0007] According to an embodiment, the fluid port may be arranged to feed the pressurized drive fluid to the drive fluid chamber, preferably the fluid port may be arranged to feed the pressurized drive fluid directly into the drive fluid chamber, the pressure housing structure remains simple and the drive fluid under pressure is fed directly into the drive fluid chamber, where it can flow into the duct (with the elongated element) without passing through the lubricant chamber.

[0008] According to the embodiment, the upstream chamber may be a dead space for the received pressurized driving fluid, and / or the upstream chamber may be devoid of a driving fluid outlet, and / or the upstream chamber may comprise a single fluid communication conduit for receiving the pressurized driving fluid. In other words, there is no (or no significant) flow of driving fluid into or through the upstream chamber. The driving fluid in the upstream chamber may be defined as a static buffer to avoid any direct leakage of lubricant to the outside of the pressure housing. When the pressurized driving fluid provided in the pressure housing and flowing into the duct has a predetermined flow rate, more than 90%, preferably more than 95%, more preferably more than 99% of said predetermined flow rate flows directly from the fluid port to the duct. This means that an actual small part of the flow (less than 10%, preferably less than 5%, more preferably less than 1%) flows into the upstream chamber. It should be noted that in the start-up step, when there is still no driving fluid in the pressure housing, there is a preparatory phase in which the pressure housing (driving fluid chamber and upstream chamber) must be filled with driving fluid, and during this preparatory phase, the driving fluid must flow into the upstream chamber. However, after this preparatory stage, there is no or very little flow of pressurized drive fluid in the direction of the upstream chamber. As a result, during the established state of laying the elongated element, there is no flow of drive fluid from the upstream chamber to the drive fluid chamber, nor through or around the lubricant chamber. The pressure housing remains compact.

[0009] According to an embodiment, the device may comprise a foam member arranged between the drive fluid chamber and the lubricant chamber, which forms the walls of the lubricant chamber and is in contact with the lubricant, allowing uniform, gentle and reliable wiping and deposition of the lubricant around the elongate element and, due to effective isolation, avoiding gross leakage of the lubricant into the drive fluid chamber.

[0010] According to an embodiment, the device may comprise a holder for receiving the foam member and maintaining it in a working position in contact with the elongated element, the holder being disposed between the foam member and the pressure housing. Such a holder, an intermediate part between the pressure housing and the foam member, allows for easy modification, easy repair, and modularity. When the pressure housing is made of an upper and lower part (or two halves), the upper part can be closed over the lower part without any foam material in between that would prevent a fluid tight seal.

[0011] According to an embodiment, the holder may be a ring, preferably a closed ring.

[0012] According to an embodiment, the pressure housing may include a groove or recess for holding the holder in place along the axial direction of the elongate element.

[0013] As an example, the foam member may have a thickness of 15mm to 45mm, for example 25mm for a φ80mm cable. The foam member may be made from polyester or polyether filter foam material.

[0014] According to an embodiment, the device may comprise a second foam member disposed between the upstream chamber and the lubricant chamber. Such second foam member forms a wall of the lubricant chamber and is in contact with the lubricant. This provides an effective separation to avoid a large amount of leakage of the lubricant into the upstream chamber.

[0015] According to an embodiment, the device may comprise a second holder for receiving the second foam member and maintaining it in a working position in contact with the elongated element, the second holder being arranged between the second foam member and the pressure housing. Such a second holder, an intermediate part between the pressure housing and the second foam member, allows easy modification, easy repair and modularity. When the pressure housing is made of an upper and lower part (or two halves), the upper part can be closed over the lower part without any foam material in between that would prevent a fluid tight seal.

[0016] According to an embodiment, the second holder may be a ring, preferably a closed ring.

[0017] According to an embodiment, the pressure housing may include a groove or recess for holding the second holder in a predetermined position along the axial direction of the elongate element.

[0018] As an example, the second foam member may have a thickness of 15 mm to 45 mm, for example 25 mm for a φ80 mm cable.

[0019] According to an embodiment, the second foam member may be made from a polyester or polyether filter foam material.

[0020] According to an embodiment, the second holder and the holder may have the same outer dimensions so as to be interchangeable.

[0021] According to an embodiment, the device may comprise a lubricant conduit arranged between the lubricant chamber and the drive fluid chamber, which ensures that excess pressure of the lubricant mixes with the drive fluid.

[0022] According to an embodiment, the lubricant conduit may be mounted at the top of the pressure housing, preferably vertically higher than the top of the cable, according to this embodiment, when the lubricant is denser than the drive fluid, it naturally surrounds the cable when introduced into the drive fluid chamber.

[0023] According to an embodiment, the lubricant conduit may be arranged on the holder.

[0024] According to an embodiment, the lubricant conduit may be a tube or a pipe that is at least partially outside the pressure housing. The lubricant conduit may be arranged to feed the lubricant into the drive fluid chamber. The installation of the lubricant conduit separate from the holder and / or the pressure housing allows a compact design in the axial direction (axial direction of the elongated element).

[0025] According to embodiments, the device may include a drive fluid conduit disposed between the upstream chamber and the drive fluid chamber, the drive fluid conduit providing fluid communication between the upstream chamber and the drive fluid chamber.

[0026] According to an embodiment, the drive fluid conduit may be a tube or pipe that is at least partially outside the pressure housing. The installation of the drive fluid conduit separate from the pressure housing allows a compact design in the axial direction (axial direction of the elongated element). Preferably, the drive fluid line may be located at the bottom (vertical direction) of the pressure housing, so that air bubbles do not accumulate in the drive fluid line and hinder the operation.

[0027] According to embodiments, the inlet port may include at least one of a lip seal and a guide block.

[0028] According to an embodiment, the device may comprise an external lubrication unit located upstream of the pressure housing.

[0029] According to an embodiment, the device may comprise drive means, such as drive caterpillars or drive rollers, arranged to force the elongate element into the inlet port.

[0030] According to embodiments, the pressure housing may include two halves attached together to enclose the elongated element.Certain embodiments provide an easy to install device.

[0031] According to an embodiment, the device may comprise a sealing element disposed between the pressure housing and the duct.

[0032] Preferably, the sealing element between the pressure housing and the duct, the (cable) lip seal at the inlet port and the holder with the foam member are all undivided and are sleeved over the cable before being mounted in the pressure housing and duct.

[0033] According to an embodiment, the drive fluid chamber may be arranged to at least partially surround the elongated element, preferably completely surround the elongated element in a tangential direction thereof.

[0034] According to an embodiment, the lubricant chamber may be arranged to at least partially surround the elongated element, preferably completely surround the elongated element in a tangential direction thereof.

[0035] According to an embodiment, the upstream chamber may be arranged to at least partially surround the elongated element, and preferably to completely surround the elongated element in a tangential direction thereof.

[0036] According to an embodiment, the upstream chamber may define a dead volume for receiving the drive fluid, in other words, the upstream chamber is a space in which there is no flow of the drive fluid, and the upstream chamber provides a pressurized space to minimize or inhibit leakage of lubricant from the lubricant chamber and, if necessary, to capture lubricant that leaks from the lubricant chamber.

[0037] According to an embodiment, the drive fluid provided in the upstream chamber may be static, except to compensate for leakage outside the pressure housing and / or into the lubricant chamber.

[0038] According to an embodiment, the driving fluid chamber may have a terminal or downstream section defined by or comprising an outlet port.

[0039] According to an embodiment, the upstream chamber may have a beginning or upstream section defined by or including an inlet port.

[0040] A second aspect of the invention is a device for installing an elongated element in a duct, comprising: - a device for installing an elongated element in a duct according to a first aspect, a drive fluid supply unit connected to the device for installing the elongated element in a duct and arranged to deliver a drive fluid under pressure to the drive fluid chamber; - a lubricant supply unit connected to a device for installing an elongated element in a duct and arranged to deliver lubricant under pressure to a lubricant chamber.

[0041] According to one embodiment, the drive fluid supply unit is arranged to deliver drive fluid at a first pressure; the lubricant supply unit is arranged to supply lubricant at a pressure of the first pressure ±10%, preferably at a pressure of up to 1 bar above the first pressure, preferably at a pressure of up to 0.5 bar above the first pressure, more preferably at a pressure of up to 0.2 bar above the first pressure.

[0042] According to an embodiment, the driving fluid may be air. The driving fluid may be a liquid, preferably 90% water. The lubricant may be oil-based or water-based with a polymer, for example, optionally with a silicone additive. Alternatively, bentonite may be used and dispersed in the driving fluid.

[0043] Another aspect of the invention is a method of installing an elongate element in a duct using the device of the first aspect, comprising the steps of: - assembling a foam member and a second foam member in a holder and a second holder, respectively; - Installing a lip seal on the elongated element; - placing a foam member-holder assembly over the elongated element; - placing a second foam member-second holder assembly over the elongate element; - installation of sealing elements above the duct, - optionally attaching the pig to the elongated element; - introducing an elongated element together with an optional pig into the duct at least 10 cm, - placing the lip seal, the guide block, the holder, the second holder and the duct in a first half of the pressure housing and installing a sealing element between the first half of the pressure housing and the duct; - attaching the second half of the pressure housing to the first half of the pressure housing such that the pressure housing surrounds the lip seal, the guide block, the holder, the second holder, the sealing element, a portion of the duct, and a portion of the elongated element to form a drive fluid chamber, a lubricant chamber, and an upstream chamber.

[0044] In the present disclosure, elongated elements can equally refer to cables, wires, fibers, optical fibers, transport tubes, bundles, or combinations of these articles. Typically, these elongated elements are covered with a protective sheath (made of insulating material such as plastic), but may also be bare wires. These elongated elements can exhibit diameters of one (or less) or a few millimeters, centimeters, and lengths of several meters, hundreds of meters, kilometers.

[0045] In the present disclosure, a duct can equally denote any hollow passage in which a conduit, a tube, a pipe, an elongated element must be laid. These ducts can be buried and can have lengths of several meters, hundreds of meters or even kilometers.

[0046] In this disclosure, the upstream and downstream directions will be taken with respect to the direction of movement of the elongated elements. As an example, looking at a pressure housing, the inlet port of the elongated element and the outlet port of the elongated element provided within the pressure housing are the upstream (inlet) port and the downstream (outlet) port, respectively. [Brief description of the drawings]

[0047] Other characteristics and advantages of the present invention will appear more clearly from the following detailed description of particular, non-limiting embodiments of the invention, illustrated by the accompanying drawings, in which FIG. 1 represents a schematic diagram of a device for installing elongated elements.

[0048] [Figure 1] A general and simplified diagram of a device according to the invention is shown: an elongated element 100 with a sealing cap 110 at its tip is driven by a driving means 80 through a pressure housing 10 and laid or placed in a duct 200. BEST MODE FOR CARRYING OUT THEINVENTION

[0049] In particular, this example shows an installation using a liquid to assist the introduction and movement of the elongated element 100 into the duct 200. Such a method is generally called floating. A pulling pig may also be used, in which case the method is called Water-Push-Pulling. Such a pig can be attached to the forward most end of the elongated element, for example, via a pulling ring, or a cable stocking, or a (splittable) clamp attached to the outer surface of the elongated element.

[0050] However, the invention can be practiced with the aid of gas (air) as the driving fluid, a process called jetting or blowing.

[0051] The pressure housing 10 includes a fluid port 15 for receiving pressurized drive fluid from a drive fluid supply unit.

[0052] The general structure of the equipment involves a pressure housing 10 that is mounted on a conduit 200 and receives the elongated element 100 for introducing it into the duct 200 together with a pressurized driving fluid. The movement of the elongated element 100 is caused by the action of a pushing force generated by the driving means 80 at the start of installation, after which the movement is caused by the combined action of the pushing force generated by the driving means 80 and the fluid drag (propulsion) force created by the driving fluid along the elongated element 100 when no pig is used as in the present case (floating). The buoyancy effect provided by the driving fluid reduces the effective weight of the cable, resulting in reduced friction and a longer installation length. When a pig is used (not pictured), a localized pulling force at the front end of the cable also contributes to the installation.

[0053] The drive means 80 may comprise a caterpillar driven by an electric motor and a counter roller (here four rollers) for clamping the elongated element 100 and ensuring little or no slippage during propulsion. However, other kinds of drive means can be used (having only two caterpillars, rollers). Typically (not shown), the elongated element 100 is stored on a reel located upstream of the drive means.

[0054] The pressure housing 10 holds a guide block 63 and a lip seal which define an inlet port 12 into the pressure housing 10 for the elongated element 100 .

[0055] The pressure housing 10 is coupled to the duct 200 by clamp rings 61 and 62 which define the exit port 11 from the pressure housing for the elongated element 100. To avoid leakage of the drive fluid, the clamp ring 61 (preferably splittable) holds a sealing element (e.g., a seal, O-ring, gasket, etc.) in contact with the outer surface of the duct 200.

[0056] Installation of the elongated element 100 into the duct 200 may be facilitated by using a lubricant to reduce friction of the elongated element 100 into the duct 200. To this end, the pressure housing 10 is designed to define three separate chambers located within the pressure housing 10 between the inlet port 12 of the elongated element 100 and the outlet port 11 of the elongated element 100.

[0057] The pressure housing 10 comprises a foam member 51 having a holder 53 and a second foam member 52 having a second holder 54. The foam member 51 and the second foam member 52 may be rings made of polyester or polyether filter foam material and surround the elongated element 100. The foam member 51 and the second foam member 52 are held and positioned within the pressure housing 10 by the holder 53 and the second holder 54, respectively, to define the interior space of the pressure housing 10 as an upstream chamber 40 located between the inlet port 12 and the second foam member 52; a lubricant chamber 30 located between the second foam element 52 and the foam element 51; -Demarcates a drive fluid chamber 20 located between the foam member 51 and the outlet port 11.

[0058] It should be noted that the elongated element 100 passes through the portions of the pressure housing 10 in the following order: i- inlet port 12 (guide block 63 and lip seal), ii—the upstream chamber 40; iii- lubricant chamber 30, iv-drive fluid chamber 20; v-out port 1 (clamp rings 61, 63).

[0059] The pressure housing 10 comprises a lubricant port 16 for delivering pressurized lubricant to fill the lubricant chamber 30. The device comprises a lubricant conduit 14, which in this embodiment may be a (partly external) tube, to provide fluid communication between the lubricant chamber 30 and the drive fluid chamber 20.

[0060] 1, the fluid port 15 is in direct communication with the drive fluid chamber 20 to supply pressurized drive fluid to the drive fluid chamber 20. In particular, it can be seen that once the pressurized drive fluid is in the drive fluid chamber 20, it can flow directly into the duct 200 through the outlet port 1.

[0061] The device also comprises a drive fluid conduit 13, which in this embodiment may be a (partially external) tube for providing fluid communication between the drive fluid chamber 20 and the upstream chamber 40. As can be seen in Fig. 1, the drive fluid conduit 13 has the main purpose of filling the upstream chamber 40 during a preparatory stage before the established operation, in which the elongated element 100 is introduced into the duct 200. In particular, after this preparatory stage, the upstream chamber 40 is filled with drive fluid, there is no or almost no drive fluid flow through the drive fluid conduit 13, and the drive fluid flow supplied through the fluid port 15 can escape solely into the duct 200.

[0062] To improve the introduction of the elongated element 100 into the pressure housing 10, an external lubrication unit 70 may optionally be provided between the drive means 80 and the pressure housing 10. This external lubrication unit 70 may comprise an external foam member 72 with an internal groove 360° around the elongated element 100, held by an external holder 71 and connected to an external lubricant reservoir 73 for depositing the lubricant by gravity.

[0063] To ease preparation of the device, the pressure housing 10 may be provided in two separate parts or halves which are joined together to sandwich the guide block 63, the lip seal, the second holder 54, the holder 53, the clamp rings 61, 62, etc. The guide block 63 and the clamp rings 61, 62 are preferably separable.

[0064] In practice, the guide block 63, the clamping rings 61, 62 halves have mating shapes and the pressure housing (also separable) has a counter mating shape. These mating and counter mating shapes can be groove-rib, pin-hole, bolt-screw. Thus, when preparing the lower half of the pressure housing, the respective halves of the guide block 63, the clamping rings 61, 62 can be placed or put in the correct position, and the same applies to the upper half of the pressure housing. To keep the components in the upper half of the pressure housing in place, the parts can be provided with a snap-fit, or a screw, or a light press-fit structure. Once all the halves are joined to the respective halves of the pressure housing, the halves of the pressure housing can be attached together. Of course, the inseparable parts (foam members and holders, lip seals...) are pre-placed on the elongated element 100 and pre-positioned in the correct axial position with respect to one half of the pressure housing (preferably the lower one).

[0065] In this embodiment, the driving fluid may be a liquid, more preferably water, fresh water or salt water. The lubricant may be oil or water based. The elongated element may be a power cable having a diameter of 80 mm and covered with plastic.

[0066] In operation, the elongated element 100 is forced into the pressure housing 10 by the drive means 80. The external lubrication unit 70 deposits a thin layer of lubricant on the elongated element 100, thus facilitating its passage through the guide block 63 and the lip seal.

[0067] Pressurized drive fluid is supplied to fluid port 15 at a pressure comprised in the range of values ​​from 0 bar to 16 bar, 20 bar or even 25 bar. The drive fluid fills drive fluid chamber 20, upstream chamber 40 (via drive fluid conduit 13) and flows into duct 200 together with elongated element 100.

[0068] Once the upstream chamber 40 is completely filled with drive fluid, all the drive fluid flows directly from the fluid port 15 to the duct 200 (as indicated by the arrow in FIG. 1). In particular, during established operation, there is no flow of drive fluid from the upstream chamber 40 to the drive fluid chamber 20 (except for a small amount of backflow, mainly via the conduit 13, to compensate for unexpected leakage through the lip seal and the guide block 63). As a result, there is no flow of drive fluid through or around the lubricant chamber 30. This allows the design and maintenance of a compact pressure housing 10. Indeed, if the drive fluid has to pass through or around the lubricant chamber 30, it is necessary to provide a passage arranged parallel to the lubricant chamber 30 and having approximately the same area as the passage space in the duct 200 defined between the duct 200 and the elongated element 100. This may disadvantageously increase the size of the pressure housing 10.

[0069] At the same time, pressurized lubricant is supplied to the lubricant chamber 30 via the lubricant port 16 at a pressure equal to or preferably slightly greater than the pressure applied to the drive fluid. As an example, if the drive fluid pressure is 8 bar, the lubricant pressure could be 8.5 bar, preferably 8.2 bar or 8.1 bar.

[0070] As a result, as shown in FIG. 1 , the lubricant can fill the lubricant chamber 30, impregnate the foam member 51, the second foam member 52, and adhere to the elongated element 100 to ensure that there is a lubricant layer on the elongated element 100, and excess lubricant leaves the lubricant chamber 30 via the lubricant conduit 14, mixes with the driving fluid in the driving fluid chamber 20, and flows into the duct 200.

[0071] The device provides a precise dosage of lubricant to the drive fluid due to its particular construction (lubricant chamber 30 separate from drive fluid chamber 20 and upstream chamber 40, lubricant conduit 14 feeding drive fluid chamber 20).

[0072] In addition, it is noted that lubricant can only leak from the lubricant chamber 30 into the drive fluid chamber 20 and / or the upstream chamber 40. Thus, a lubricant leak from the lubricant chamber 30 does not cause any external lubricant leakage, and the device collects the leaked lubricant in the drive fluid. If the upstream chamber 40 leaks through the lip seal and the guide block 63, pressurized drive fluid (water) will leak to the outside, with less serious consequences compared to an external leakage of lubricant. In fact, an external lubricant leak should be avoided for environmental reasons, and pressurized lubricant released on the drive means may cause slippage problems.

[0073] It should be noted that along the vertical direction, the lubricant conduit 14 is positioned above the pressure housing 10. If the lubricant is denser than the drive fluid, the lubricant may flow out of the reservoir at a lower level than would be necessary to completely surround the cable if the lubricant conduit 14 were located at the bottom of the pressure housing, thus avoiding this waste. Also, in that case, the lubricant port 16 is preferably located at the bottom so that the lubricant always passes (surrounds) the cable as it flows out through the lubricant conduit 14.

[0074] Note that along the vertical direction, the drive fluid conduit 13 is positioned below the pressure housing 10 to avoid any air bubbles or voids that may impede the passage of the drive fluid.

[0075] Of course, it will be appreciated that obvious improvements and / or modifications may be made by those skilled in the art and still fall within the scope of the present invention as defined by the appended claims.

[0076] In particular, the lubricant conduit 14, which is shown as a tube external to and separate from the pressure housing 10, may be provided as a slot or hole through the holder 53 to provide fluid communication between the lubricant chamber 30 and the drive fluid chamber 20. Also, the drive fluid conduit 13, which is shown as a tube external to and separate from the pressure housing 10, may be provided as an internal conduit within the pressure housing 10 between the upstream chamber 40 and the drive fluid chamber 20, or as an offshoot of the fluid port 15, for example as a Y-junction.

[0077] In the above embodiment, the driving fluid is a liquid, more preferably water, fresh water or salt water. The lubricant is oil or water based. The elongated element is a power cable with a diameter of about 80 mm and covered with plastic. However, the device depicted in FIG. 1 can be used for other applications with other fluids and for other sizes of elongated elements 100.

[0078] Optionally (not shown), a small amount of driving fluid (water) can be pumped into the upstream chamber 40 through a small water port (not shown) at a pressure slightly higher than the pressure in the driving fluid chamber 20 to continuously dilute the fluid in the upstream chamber 40 and avoid accumulation (saturation) of lubricant in the upstream chamber 40.

Claims

1. A device for installing an elongated element (100) in a duct (200), comprising a pressure housing (10), said pressure housing (10) comprising: an inlet port (12) for receiving said elongated element (100); an outlet port (11) arranged to be connected to said duct (200) in order to introduce said elongated element (100) into said duct (200) together with a driving fluid; a drive fluid chamber (20) arranged to receive said drive fluid supplied under pressure and to distribute said drive fluid in said duct (200) comprising said elongated element (100); a lubricant chamber (30) arranged to receive a lubricant and distribute said lubricant on the outer surface of said elongated element (100), said lubricant chamber (30) being located upstream of said drive fluid chamber (20); The device is characterized in that the pressure housing (10) is arranged to receive the drive fluid under pressure and comprises an upstream chamber (40) located upstream of the lubricant chamber (30).

2. 2. The device of claim 1, wherein the pressure housing (10) comprises a fluid port (15) for receiving the pressurized drive fluid, the fluid port (15) being arranged to deliver pressurized drive fluid to the pressure housing (10) downstream of the lubricant chamber (30).

3. 3. The device of claim 1 or 2, wherein the fluid port (15) is arranged to feed pressurized drive fluid into the drive fluid chamber (20), and preferably the fluid port (15) is arranged to feed pressurized drive fluid directly into the drive fluid chamber (20).

4. 2. The device of claim 1, wherein the upstream chamber (40) is a dead space for the received pressurized drive fluid.

5. The device of claim 1, further comprising a foam member (51) disposed between the drive fluid chamber (20) and the lubricant chamber (30).

6. 6. The device according to claim 5, further comprising a holder (53) for receiving the foam member (51) and maintaining the foam member (51) in a working position in contact with the elongated element (100), the holder (53) being disposed between the foam member (51) and the pressure housing (10).

7. The device of claim 1, further comprising a second foam member (52) disposed between the upstream chamber (40) and the lubricant chamber (30).

8. 8. The device of claim 7, further comprising a second holder (54) for receiving the second foam member (52) and maintaining the second foam member (52) in a working position in contact with the elongated element (100), the second holder (54) being disposed between the second foam member (52) and the pressure housing (10).

9. 9. The device according to claim 7 or 8, wherein the second holder (54) and the holder (53) have the same external dimensions so as to be interchangeable.

10. The device of claim 1, further comprising a lubricant conduit (14) disposed between the lubricant chamber (30) and the drive fluid chamber (20).

11. 11. The device according to claim 10, wherein the lubricant conduit (14) is mounted in an upper part of the pressure housing (10), preferably vertically higher than the top of the elongated element (100).

12. 11. The device according to claim 10, when dependent on claim 7, wherein the lubricant conduit (14) is arranged on the holder (53).

13. The device of claim 1 , comprising a drive fluid conduit (13) disposed between the upstream chamber (40) and the drive fluid chamber (20).

14. The device of claim 1 , wherein the inlet port (12) comprises at least one of a lip seal and a guide block (63).

15. 2. The device of claim 1, comprising an external lubrication unit (70) located upstream of the pressure housing (10).

16. 2. The device of claim 1, comprising drive means (80), such as drive caterpillars or drive rollers, arranged to force the elongate element (100) into the inlet port (12).

17. 2. The device of claim 1, wherein the pressure housing (10) comprises two halves attached together to surround the elongated element (100).

18. The device of claim 1, comprising a sealing element disposed between the pressure housing (10) and the duct (200).

19. 2. The device according to claim 1, wherein the driving fluid chamber (20) is arranged to at least partially surround the elongated element (100), preferably to completely surround the elongated element (100) in the tangential direction.

20. 2. The device according to claim 1, wherein the lubricant chamber (30) is arranged to at least partially surround the elongated element (100), preferably to completely surround the elongated element (100) in the tangential direction of the elongated element (100).

21. 2. The device of claim 1, wherein the upstream chamber (40) is arranged to at least partially surround the elongated element (100), preferably to completely surround the elongated element (100) in a tangential direction of the elongated element (100).

22. The device of claim 1 , wherein the upstream chamber (40) defines a dead volume for receiving the drive fluid.

23. A device for installing an elongated element (100) in a duct (200), comprising: - a device for installing an elongated element (100) in a duct (200) according to claim 1, a drive fluid supply unit connected to said device for placing an elongated element (100) in a duct (200) and arranged to deliver said drive fluid under pressure to said drive fluid chamber (20); - a lubricant supply unit connected to said device for placing an elongated element (100) in a duct (200) and arranged to deliver said lubricant under pressure to said lubricant chamber (30).

24. - said drive fluid supply unit is arranged to deliver said drive fluid at a first pressure; 24. Apparatus according to claim 23, wherein the lubricant supply unit is arranged to deliver the lubricant at a pressure of ±10% of the first pressure, preferably at a pressure of up to 1 bar above the first pressure, preferably at a pressure of up to 0.5 bar above the first pressure, more preferably at a pressure of up to 0.2 bar above the first pressure.

25. A method for placing an elongated element (100) in a duct (200) using a device according to claim 18, when dependent on claims 17, 14 and 8, comprising: - assembling said foam element (51) and said second foam element (52) in said holder (53) and said second holder (54), respectively; - placing said lip seal on said elongated element (100); - placing the foam member (51)-holder (53) assembly on the elongate element (100); - placing said second foam member (52)-second holder (54) assembly on said elongate element (100); - placing said sealing element on said duct (200), - optionally attaching a pig to said elongated element; - introducing said elongated element (100) together with the optional pig into said duct (200) for at least 10 cm, - placing the lip seal, the guide block (63), the holder (53), the second holder (54) and the duct (200) in the first half of the pressure housing (10) and installing the sealing element between the first half of the pressure housing and the duct, - attaching a second half of the pressure housing (10) to the first half of the pressure housing (10) so as to surround the lip seal, the guide block (63), the holder (53), the second holder (54), the sealing element, a portion of the duct (200), and a portion of the elongated element (100) with the pressure housing (10) to form the drive fluid chamber (20), the lubricant chamber (30), and the upstream chamber (40).

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