NO20150110A1 - A support device - Google Patents

Description

A support device

Field of the invention

The invention concerns a support device for an elongate member, as set out by the preamble of claim 1. The invention is particularly useful for supporting a pipe connected to a submerged pump.

Background of the invention

Referring to figure 1, firewater systems for floating vessels 1 (ships, platforms, etc.) normally comprise a power unit 2 (e.g. a diesel-driven power generator) that is connected (e.g. via electrical wires, not shown) to a submerged pump 3 (typically håving an electrical motor) arranged in an opening 23 in the vessel hull, below the water surface W. The submerged pump 3 is arranged at the end of a pipe 11 which extends in a caisson 5 from the vessel deck D. On the deck, the pipe 11 is connected to one or more pipes 4, and thus supplies water to firefighting equipment, sprinkler systems, etc. This configuration is well known in the art.

From time to time, the submerged pump must be retrieved to the deck for repair, refurbishment or replacement. This operation entails disconnecting the pipe 11 from the distribution pipes 4 (and ancillary support members; not shown) and temporarily suspending the pipe 11 (to which the submerged pump 3 is connected) by temporary support structures. One such known temporary support structure, which is shown in figure 2 and commonly referred to as a hang-off tool, comprises a frame structure håving four interconnected frame members 6a-d, configured for being placed on the deck D, and provided with lifting bars 8. The known hang-off tool comprises support tabs 7, on which the pipe is supported (e.g. via a pipe flange). In use, the frame members are disconnected and placed around the pipe 11, whereupon the pipe flange is lowered such that the pipe - and pump - are supported by the hang-off tool. The individual frame members are relatively heavy (e.g. 60 - 80 kg) and require multiple persons or a crane for lifting an handling. The process of assembling and disassembling the hang-off tool is therefore time-consuming and potentially hazardous.

It is therefore a need for a hang-off tool that is more efficient in use, as well as being safer and easier to operate.

Summary of the invention

The invention is set forth andcharacterized inthe main claim, while the dependent claims describe other characteristics of the invention.

It is thus provided a support device for supporting an elongate object, comprising a plurality of support units each håving a support member,characterized in thatthe support member is movable between a stand-by state in which the elongate object is not supported, and an activated state in which the elongate element is supported by and hanging from the support members.

The plurality of support units comprise in one embodiment fastening means configured for connecting the support unit to a structure surrounding the elongate object.

The support member is in one embodiment hinge-connected to a footing and comprises an abutment member arranged in the region of the free end of the support member.

In one embodiment, the abutment member is releasably connected to the support member and arranged to carry axial loads imposed by the elongate element.

In one embodiment, the support member comprises an abutment surface arranged in the region of the free end of the support member and arranged to carry lateral loads imposed by the elongate element.

The support member comprises in one embodiment a lever arm configured to move the support member between the stand-by state and the activated state.

The invented support device is particularly useful as a hang-off tool for suspending a pipe extending into a caisson; wherein the plurality of the support members are connected to a flange member on the caisson.

It is al so provided a method of installing a pipe in a caisson by means of the support device according to the invention, comprising the steps of: a) attaching the support units to the caisson and arranging the support units in a stand-by state; b) lowering a first pipe section into the caisson; c) moving the support member on each of the support units to an activated state, and continue to lower the first pipe section until an abutment element on the first pipe section is being supported by the support members; d) connecting a second pipe section to the upper end of the first pipe section while the latter suspended by the support units; e) lifting the pipe sections sufficiently for the support members to be moved to the stand-by state, and then continue lowering the pipe sections into the caisson.

Brief description of the drawings

These and other characteristics of the invention will become clear from the following description of a preferential form of embodiment, given as a non-restrictive example, with reference to the attached schematic drawings, wherein: Figure 1 is a schematic figure showing a typical arrangement of a submerged pump on a ship, as discussed above in the section titled "Background of the invention"; Figure 2 is a perspective view of a prior art hang-off tool, as discussed above in the section titled "Background of the invention"; Figure 3 is a perspective view of an embodiment of the invented support device in use, supporting a pipe; Figure 4 is a perspective view of the same embodiment as in figure 3, but from a different perspective; Figure 5 is a perspective view corresponding to figure 3, but shows the support device in an open, or standby, position where the pipe is not supported; Figure 6 corresponds to figure 5, but the pipe has been removed; Figure 7 corresponds to figure 3, i.e. showing the support device in a closed (activated) position, but without the pipe; and Figure 8 is a perspective, and partly exploded, view of a support unit of the support device.

Detailed description of a preferential embodiment

The following description may use terms such as "horizontal", "vertical", "lateral", "back and forth", "up and down", "upper", "lower", "inner", "outer", "forward", "rear", etc. These terms generally refer to the views and orientations as shown in the drawings and that are associated with a normal use of the invention. The terms are used for the reader's convenience only and shall not be limiting.

Figure 3 shows the aforementioned pipe 11 being supported by the support device 24, also referred to as a hang-off tool. The invented hang-off tool 24 comprises in the illustrated embodiment four support units 25, one of which is shown in figure 8.

Turning initially to figure 8, each support unit 25 comprises a footplate 14 configured for assembly and connection onto (via bolt holes 21) onto caisson flange 10 (see e.g. figure 7). A movable lug, also referred to as a rocker arm, 13 is hinge-connected via a support 16 and bolt 22 to the footplate 14. In the illustrated embodiment, the rocker arm 13 comprises a lever arm 15 (for manoeuvring the rocker arm) and an abutment member 18, releasably arranged on the rocker arm free end via screws 20. The abutment member

18 may thus be replaced, if needed. The abutment member 18 comprises a first support surface 26, and a second support surface 19 is arranged in the region of the rocker arm free end. Both support surfaces will be described below. Figure 7 shows four support units, labelled 25a-d, assembled on a flange 10 of a caisson 5 extending above a deck D. Each support unit 25a-d in connected to the caisson flange via bolts 21a. The support units are assembled at regular intervals around the flange 10, and are shown in an activated - or closed - state, i.e. each one of the rocker arms 13 have been rotated to an inward-pointing position. Figure 6 shows the same four support units 25a-d assembled on the flange 10, as in figure 7. However, here the support units are shown in a standby - or open - state, i.e. each one of the rocker arms 13 have been rotated to an upward-pointing position, allowing passage into and out of the caisson. Figure 5 also shows the support units 25a-d in the open position, and a water pipe 11 is extending into the caisson (suspended by structures not shown in the figure). Returning to figure 3, the four support units 25a-d are shown in the activated - or closed - state (i.e. the fourth support unit 25d is hidden behind the pipe). In this state, each of the support units 25a-d support the pipe 11 via the aforementioned abutment member 18. Each abutment member bears against a connection flange 12 on the pipe 11 and the pipe 11 (and the submerged pump attached to it, not shown) is effectively suspended by the four support units 25a-d.

The first support surface 26 of each abutment member 18 carries the axial (i.e. in the pipe-longitudinal direction) loads of the pipe 11. In one embodiment, each second support surface 19 is configured and dimensioned such that they abut against the pipe 11 and thus provide lateral (i.e. substantially normal with respect to the pipe longitudinal axis) support for the pipe 11.

Also, figure 3 clearly shows that the support units (i.e. the invented hang-off tool 24) do not interfere with piping 9 (for control wires, instrumentation, power cables, etc.) that is attached to the pipe 11.

In use, for example in installing a submerged pump 3 in a caisson 5, the invented hang-off tool 24 can be operated as follows: 1. Attaching the support units 25a-d to the caisson flange and arrangjng the support units in a stand-by (open) state (see figure 6); 2. Lowering the pump 3, attached to a pipe 11, into the caisson (see figure 5), hanging, for example by a crane (not shown); 3. Moving the rocker arm 13 on each of the support units to the activated (closed) state, and continue to lower the pipe until the pipe flange 12 is resting on (and thus being supported by) the rocker arms 13; 4. Disconnecting the crane (not shown) and connecting a new length of pipe 11' while the pipe 11 is hanging from the support units (see figure 3). 5. Reconnecting the crane (not shown) and lifting the pipes 11, 11' sufficiently for the rocker arms to be moved to the open (stand-by) state, and then continue lowering the pipes into the caisson.

The above steps are repeated until the submerged pump has reached its designated position, i.e. at the hull opening 23.

The invented hang-off tool 24 is an efficient tool for installing a submerged pump (and for repair, maintenance and replacement) that is connected to a pipe, extending in a caisson as shown. It should be understood, however, that the hang-off tool may be applicable for supporting (suspending) also other objects.

While the invention shall not be limited to a specific material, the support unit parts may conveniently comprise stainless steel of grade 316 or similar.

While the invention has been described with reference to an embodiment håving four support units 25a-d, the invention is not limited to this quantity. The skilled person will understand that fewer and more support units are possible. An embodiment of the hang-off tool håving three support units spaced equi-distant around the caisson flange is conceivable.

The invented hang-off tool is easy and safe to use. Compared to the hang-off tools of the prior art, each support unit of the invented tool is much lighter, for example on the order 25 kg; a weight which is easily handled by an individual.