CA1142054A

CA1142054A - Articulated fluid loading arm

Info

Publication number: CA1142054A
Application number: CA000344283A
Authority: CA
Inventors: Joel Fusy; Franz Hirschfeld
Original assignee: FMC Europe SA
Current assignee: FMC Technologies SAS
Priority date: 1979-02-12
Filing date: 1980-01-23
Publication date: 1983-03-01
Also published as: IT1220965B; DE3005216C2; DE3005216A1; GB2042466A; GB2042466B; FR2448496B1; JPS6119519B2; FR2448496A1; DE8003719U1; IT8019758A0; JPS55107700A

Abstract

ABSTRACT OF THE DISCLOSURE
A fluid loading arm including an articulated product tube and an articulated support structure each having an inboard limb or section and an outboard limb or section. The product tube and the support structure are mounted on a vertical riser where they are supported for pivotal movement about both a vertical axis and a horizon-tal axis. The inboard and outboard limbs of the support structure are joined for pivotal movement about a first horizontal axis, the inboard and outboard limbs of the product tube are pivotally joined for movement about that first axis or a second horizontal axis parallel thereto, and the outboard limb of the product tube is pivotally connected to the outboard limb of the support structure about still another parallel horizontal axis.

Description

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BACKGROUND OE TEIF I~ TION
Field of the Invent;on This invention relates to fluid loading arms, and more particularly to an articulated loading arm for cryo-genic and/or corrosive fluids.
Description of the Prior Art Fluid loading arms constructed of articulated pipe are extensivel~ used in the petroleum industry for transferring oil or other fluids between a jetty, whar~
or other loading station and a marine tanker moored along-side~ Such an arm generally comprises an inboard boom or limb ~upported on a vertical riser pipe by pipe swivel joints to facilitate pivotal movement about horizontal and vertical axesj and an outboard boom or limb connected by a pipe swivel joint to the inboard limb so as to be pivotal relative thereto about a horizontal axis. The outer end of the outboard limb is adapted to be connected to a pipe manifold on a tanker located within reach o the.
loading arm.
Some fluids beîng transferred through loading arms have special characteristics, such as a corrosive : nature, which makes it necessary for the product tube tobe fabricated from stainless steel or other rel~tively difficult-to-work material. In order that the product ~5 tube o the arm is self-supporti~g it must be constructed from thick-walled, heavy pipe and joint elements thak are very.costly when manufactured from corrosion-resistant materials. Other prior arms compxise a relatively light weight, corrosion-resistant product tube supported by a beam or truss assembly of common steel or other less ::`
, expens.ive composition, but serious problems resulting from differential thermal expansion and contraction of the product tube and its support ....
`. arise when arms of this design are employed in transfer of cryogenic ` fluids.
i~ What is needed is a loading arm with a relatively lightweight .i product tube which can be constructed from material containing the ~;~ necessary properties needed for transferring corrosive and/or cryogenic !,,~.,~ fluids, and a separate structural assembly of less expensive and more ~- workable material connected to and supporting the product tube in a way that fully facilitates differential thermal expansion and contraction ~; between the tube and its support.
S~MMARY OF nlE INVENTION
The present invention provides an articulated fluid loading arm in combination with an articulated support structure having an outboard ; section pivotally supporting an outboard portion of the arm, and a ~ vertical riser rotatably supporting an inboard section of the support `~;
and an inboard portion of the arm for rotation about a ver~ical axes, i wherein the improvement comprises: a tubular race and bearing joint `` pivotally supporting the inboard section of the support for vertical ~`. 20 swinging about a horizontal axis, the bearing having an inboard end . rotatably mounted to the riser for rotation about the vertical axis, the inboard portion of the arm having a horizontal pipe passing through the : race and bearing joint coaxial with the horizontal axis and end connected to one end of a fluid swivel joint having a second end rotatably mounted to the riser for rotation about the vertical axis, the one end of the fluid swivel joint partially passing into the race and bearing joint ~ permitting thermal expansion and contraction of the horizontal pipe.
i~ BRIEF DESCRIPTION OF THE DRAWINGS
`~ Eigure 1 is a diagrammatic isometric of one embodiment of a `i. 30 fluid loading arm according to the present invention, illustrating the ....
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, parallel arrangement of the support structure and the product tube.
Figure ~ is an enlarged rear elevation of the loading arm of Figure 1.
Figure 3 is an enlarged side elevation of the loading arm of Figure l.
Figure ~ is an enlarged fragmentary rear elevation of the loading arm of Figure 1, partly in section, showing details of a means for mounting the arm on the riser.
Figure 5 is an enlarged fragmentary rear elevation, partly in section, showing details of the articulated connections between the inboard and outboard limbs of the loading arm of Figure 2.
Figure 6 is an enlarged fragmentary elevation, partly in section, of the loading arm of Figure 1, taken in the direction of the arrows 6-6.
Figure 7 is a side elevation of a portion of the loading arm elements shown in Figure 6.
Figure 8 is another embodiment of the loading arm shown in Figures 1-7~ showing details of the articulated connections between the inboard and outboard limbs.
Figures 9 and 10 are diagrammatic isometric views of further embodiments of a loading arm according to the ` present invention.
Figure 11 i5 an isometric view of still another embodiment of a loading arm according to the present . 5 invention, wherein the support structure can also conduct 1uid~
DESCRIPTIO~ OF THE PREFERRED EMBODIMENTS
First Embodimen-t ~ Fiqs. 1~7 One embodiment of fluid loading arm 11 i~
. 10 accordance with the present invention comprises an articu-: lated product tube 12 (Fig. 1) mounted in a parallel . arrangement with an articulated support structure 13. The proauct tube 12 (Figs. 1, 2) includ~s an i.nboard limb 17 : pivotally connected to an outboard limb 18 by a swivel joint 19 ori.ented about a horizontal axis A. ~he.parallel mounted support structure 13 includes an inboard section 23 pivotally connected to an outboard sect.ion 24 by a swivel joint 25 oriented about a horizontal axis B that is parallel to or coaxial with the axis A. The inner end

2~ of the inboard limb 17 is coupled to a vertical riser 29 (Figs. 1-4) by a pair of swivel joints 30,31 (Figs. 2, 4) and a pair of albows 35~36.for pivotal movement about a vertical axis C and a horlzontal axis E, the axis F being parallel to the axes A and B. The inner end of the in-board support section 23 is coupled to the vertical riser 29 by a bracket 37 and a pair of swivel joints 41,42 for pivotal movement about the same vertical axis C and hori-zontal axis F.
The swivel joint 42 (Fig. 4) comprises an inner annular male element 42a fixed to the upper portion 29a s~
of the riser 29, an outer annular female elernent 42b surroundihg and coaxial with the riser portion 2ga, and a plurality of balls or other suitable rollable bearing ele-ments 47 in raceways 48 that rotatably interconnect the S male and female elements 42a,42b. An annular support plate 49, having a central bore 53, is welded or otherwise con-nected to ~he top of the female joint element 42b, and - an insulating sleeve 54, which is secured to the plate 49 and an upper annular plate 55, provide~ ~hermal insula-tion and suppor~ ~or the swivel joint 31 which also is welded or otherwise connected to the plate 55.
The bracket 37 and a plate 5g (Fig. 4), which are welded or otherwise connected together and to the plate 49, provide a support for the inner element 59 of the swivel joint 41. The outer element 60 of the joint 41 is welded or otherwise connected to ~he inboard section 23 of the support structure 13, and the inner and outer join~
elements 59 and 60 are rotatably interconnected by a plurality of rolla~le bearing elements 63 in the conven-tional mannerv The upper portion 29a of the xiser 29 is secured to a lower riser portion 29b (Fig. 2) by a bracket comprising a gusset 64 and a plate 65. The riser 29 is secured in a vertical attitude to a dock or wharf 68 (Figs. 1-3), such as by a plurality of gussets 6g and a base plate 70. An inlet pipe 72 (Figs, 1, 2, 4), coupled to the lower end of the swivel joint 31 by suitable piping 73 (Fig 4), ~onducts fluid to or from the inner end of the product tube.
The swivel joint 25 (Fig. 5) comprises an annular inner element 76 and an annular outer element 77 rotatably _5_ .

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interconnected by a bearing system such as a plurality oE
balls or-other suitable rol.lable bearing elements 78. A
pair o~ plates 81a,81b a.re welded or otherwise connected to the outer element 77 and the outer end of the inboard section 23 of the support structure 13. A connecting bracket 82 (Fig. 5), having a generally U-shaped outer portion 82a and a fla~ inner portion 82b is welded or otherwise fixed to the inner end of the support structure's outboara section 24 and one end of the inner bearing eie-ment 76 to support the outboard section 24.
The outer end of the support structure's outboardsection 24 is pivotally secured to the outboard limb 18 of the product tube 12 by a swivel joint or othex rotatable bearing 88 oriented on a horizontal axis G parallel to the axes ~, B and F. The bearing or joint 88 comprises an outer or ~emale element 88a, an inner or male element 88b, and balls or other rollable bearing elements 88c. The outer or female element 88a of the bearing 88 is fixed to the outboard section 24 by a pair of brackets 84,85, and the inner or male element 88b o~ the bearing is secured to the outboard limb 18 by a pipe section 89 welded or other-wise fixed to the limb 18.
The inner bearing element 88b and the pipe sec-tion 89 have opposed flanges 90,91 interconnected by a plurality of circt~ferentially spaced bolts 92, and an insulating gasket 93 mounted between the flan~es 90,91, provides a thermal barrier which reduces the transfer of heat between the support structure 13 and the product tube 12~ The pipe 89 is connected to the outboard limb 18 at a point which causes the outboard limb to be substantially `~:
balanced about ~he axis G when the swivel joint 19 (Fig~
.. 1) is dismantled and the outboard limb 1$ is disconnected ~` from the inboard limb 17. This facilitates repair and/or , .
:. replaceme~t of the swivel joint 19. In the usual manner, ":
` 5 the product tube 12 carries at its outer end a triple pipe ~ swivel ~oint assembly 94 (Fig. 1) comprising firs'c, second .. and third swivel joints 95, 96 and 97, respectively, interconnected by a plurality of pipe elbows 98, 99 and '` 100.
The support structure 13 (Figs 1-3) includes a .~
; pantograph assembly comprising an inboard sheave 106, an ~ outboard sheave 107, a hydraulic ram 108 and a pair of ;.` cables 112,113. The sheave 106 i.s rotatably mounted on ~' the lowe.r end of the inboard section 23t coaxially with a ::.
.~ 15 horizontal axis D, by an axle 114 (F.ig. 2) which extend.s ~: - transverse~y through the section 23 The sheave 107 (Fig~ 5~ is mounted on the inner element 76 of the swivel joint 25 at the outer end of -the inboard section, and is . .
~. fixed to the inner por-tion o~ the ou~board section 24 by a !~'" 20 bra~ke~ 118 and a brackek 119 ~hak are welded or otherwise ~ fixed to the sheave 107 and the section 24 respectivel~.
. .
The bracket 118 and the brace 119 are connected together by a plurality of bolts 120 to facilitate disconnecting the bracket from the brace during repair of the su~port ~ 25 structure 13. The cables llZ and 113 (Figs. 1-3) are `'~. trained about the sheaves 106,107 wikh the inboard ends `. of these cables secured to the inboard sheave 106 and the . outer ends of these cables secured to the out~oard sheave 107 The hydraulic ram 108 (~ig. 3), connected between the sheave 106 and an ear 124 which is welded or otherwise . . .

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connected to the irlbc)ara section 23, rota-tes the inboard sheave 106 about the a~is D to pivo-t the sheave 107 and the outboard section 24 about the a~is B for raising and lowering the outboard section 24 of the support structure 13 and the outboard limb 18 of the product tube 12.
As illustrated in Figure 3, the articulated support structure 13 includes a counterweight 125 designed to neutralize the majority of the weight of the support structure 13 and of the articulated product tube 12 about the axis D. The counterweight 12S is connected to a beam 126 which is secured to the sheave 106 by the axle 114 (Fig. 2), thereby rotating about the axis D along with the sheave 106.
The inboard section 23 of the support structure 13 is pivo~ed relative to the riser about the horizontal axis F (Figs. 1-4) by means of a sheave and cable assern~ly comprising a plurality of sheaves 130-132, a pair of cables 136,137, and a hydraulîc ram 138. The sheave 130 is welded or otherwise fixed to the bracket 37 (Fig. 2) and does not rotate, and the sheave 131 is rotatably mounted on a shaft 142 that is fixed to the inboard section 23.
One end of the cable 136 (Fig. 2) is trained around and secured to the sheave 130, the other end i~ secured to a piston rod 144 which is connected to a piston ~not shown) ~5 inside the cylinder of the ram 138, and the mid-portion of the cable is trained around the sheave 131. ~he sheave 132 is rotatably mounted on a shaft 143 tha-t is fixed to the inboard section 23 of the support structure. One end of the cable 137 is trained around and secured to the sheave 130, and the other end is trained around the sheave Z~S~

132 and is secured to a piston xod 145 (Fig 2) which is also connected to the piston inside the hydraulic ram 13g.
Thus, conducting ~luid under pressure through an inlet/ou~let vent 149 to the lower portion of the ram 138 while ventiny fluid ~rom the upper portion o$ the ram thxough the inlet/outlet 150 causes the ram piston to move downward and the inboard section 23 (Fig. 3) to pivot counterclockwise about the axis F, thereby lowering the ou~board end of the section 23~ In a similar mannerr conducting fluid under pre.ssure through the inlet/outlet 15~ to the upper portion of the ram 138 while venting fluid from the lower portion of the ram causes the ram piston to move downward, thereby elevating the outer end of the inboard section 23.
Second Embodiment ~ second embodim~-nt of articulated fluid loading arm according to this inv~ntion is partially illustrated in Figure 8, and includes means for mounting a horizontal por~
tion o the product tube inside, but spaced from, the hollow swivel joints 25 and 41. The vertical riser conduit 73 and the outboard limb 18 of the second embodiment are the same as in the first e.mbodiment of Figures 1-7. In this second embodiment, a swivel joint 30a is mounted inside~
spaced from, and coaxial with the swivel. joint 41. An elbow 35a interconnects the swivel joint 30a and the swivel joint 31. A short length of tubing 151 interconnects the swivel joint 30a and the elbow 36a of the inboard limb 17a of the product tube 12a~ A swivel joint l9a, coaxial with the swivel joint 25, is located inside and spaced from, bu~

3~ not connected to, the joint 25. A short length of tubing ` ~4~(~5~
....
...`
` 155 and an elbow 156 interconnect the outer end of the inboard limb 17a and the swivel joint l9a, a~d an elhow :: .
157 interconnects the swivel joint l9a and the inner end :............... of the outboard limb 18. Other portions of the second ;~
.: 5 embodiment are the same as the embodiment of Figures 1 7.
.;~:
.. Contraction and expansion o~ th~ length of the limb 17a may . ~
.`~ cause the swivel joint l9a to move closer to the inner .:
element 76 of the swivel joint 25, but proper spacins . prevents their interference~

Third Embodiment `~ A third embodiment of articulated fluid loading arm according to this invention .is shown in Figure 9.
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. ~ .
This embodiment includes means for mounting a horizontal ~`` portion of the product tube 12b through hollow swivel joint `~; 15 - 41 as shown in Figure 80 but has a product tube 12b with an . . ~ .
inboard limb 17b and an outboard limb 18b each of ~hich is ~; somewhat shorter than the corresponding limbs of th~ pro~
r`:' duct tube 12a of Figure 8. The limbs 17b,18b are inter-~ .,.
t;~ connected by a short length of tubing 160 and a swivel joint 19b, positioned a suitable distance below the swivel joint 25. The inner and outer ends of the product tube 12a are supported in the manner disclosed in Figures 1-7.
`~;;' Fourth Embodiment A fourth embodiment of articulated fluid loading arm according to the present invention, illustrated in Figure 10, also includes means for mounting a hor.izontal portion of the product tube 12c through the hollow swivel joint 41 as shown in Figure 8, and longer inboard and out .~. board limbs 17c,18c to position an interconnecting length of tubing 162 and swivel joint l9c above the swivel joint ~ --1 0 :
, .~
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25o The inner and outer end oE the product tube 12c are supported as shown in Figures 1-7.
Fifth Emboaiment The embodiment of articulated fluid loading arm according to this invention that is illustrated in Figure 11 is similar to that of Figures 1-7, except that the sup-port structure 13d is constructed of pipe or other fluid conducting elements, thereby providing two separate flow conduits between dock 68 and the tanker (not shown~. The outboard section 24d of the support product structure 13d carries at its outer end a triple pipe swivel joint asse~bly 166 comprising first, second and third pipe swivel joints 167, 168, 169 interconnected by a pair of pipe eIbows 173,174, and the outer end of the product limb 18d termi-nates in a similar triple swivel assembly 175~ The limb18d is pivotally connected at 190 to the support-product sec~ion 24d in the same general manner shown in Figures 1-7. The inboard end of the product tube is mounted for suppor~ on a riser 29d in the manner shown in Figures 1-7.
The inboard end of the support structure is connected to the hollow riser 29d by a pair of swivel joints 179,180 interconnected by a pipe elbow 184. A pipe elbow 135 at the inboard end of the product tube extends through the ' side wall of the elbow 184 and is welded to the elbow 184 to provide a fluid tight seal in the side wall o~
the elbow 184. A vertical pipe 178 connected between the lower end of the pipe elbow 135 and an inlek pipe 172 to convey fluid to the product tube 12d. Another inlet pipe 185 welded to the riser ~9d conveys fluid into the space between the inner wall of the riser 29d and the outer ~2~

wall of the vertical pi~e 17~. Thus, fluid can flow from the inlet pipe 172, through the ~ertical pipe 17l3 and through the product tube 12d to the swivel joint assembly 175, and a separate ~luid can flow :Erom the inlet pip2 1~5, through the space between the riser 23d and the p;pe 17~, throu~h the support structure 13d to the s-~Yivel joint assembly 166. The m2ans for raising and lowering the loading arm O-L Figure 11 (only partly shown) is simi-.
lar to the ~eans shown in Figures 1-7.
` l~ The pre~ent invention provides an articulated i~ support structure mounted on a riser alld corlnect~d at both ends to corresponding ends o~ an articulated product tube to p.~ovide support ro.r the produc~ tube. This allows the use oi lightweight material in the product tub2 and reduces ~ 15 the cost of construction.
.. Although the best mode contemplated ~or carrying out the ~xesent invention has been herein shown and descri~ed, it will be apparent that mod.ificafion and varia-tion may be made wi-thout departing from ~hat is regarded to b~ t~e su~ject ~tter of -the invention.
LBG:cds `

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Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. An articulated fluid loading arm in combination with an articulated support structure having an outboard section pivotally supporting an outboard portion of the arm, and a vertical riser rotatably supporting an inboard section of the support and an inboard portion of the arm for rotation about a vertical axes, wherein the improvement comprises:
a tubular race and bearing joint pivotally supporting the inboard section of the support for vertical swinging about a horizontal axis, the bearing having an inboard end rotatably mounted to the riser for rotation about the vertical axis, the inboard portion of the arm having a horizontal pipe passing through the race and bearing joint coaxial with the horizontal axis and end connected to one end of a fluid swivel joint having a second end rotatably mounted to the riser for rotation about the vertical axis, the one end of the fluid swivel joint partially passing into the race and bearing joint permitting thermal expansion and contraction of the horizontal pipe.

2. The articulated fluid loading arm and support, as claimed in Claim 1, wherein the outboard section of the support is pivotally connected to the inboard section by a second tubular race and bearing joint for vertical swinging about a second parallel horizontal axes, and a second horizontal pipe connected at one end to the inboard portion of the arm and connected at a second end to a rotatable fluid coupling connected to the outboard portion of the arm, the horizontal pipe and fluid coupling passing into and through the second tubular race and bearing joint coaxial with the second horizontal axis permitting thermal expansion and contraction of the second horizontal pipe.

3. The articulated fluid loading arm and support, as claimed in Claim 2, wherein the horizontal pipes are each end connected to respective elbows connected to opposite ends of the inboard portion of the arm.

4. The articulated fluid loading arm and support, as claimed in Claim 1, wherein the inboard section of the support is provided with an aperture, and a second horizontal pipe passing through the aperture and connected at one end to an elbow end of the inboard portion of the arm and connected at a second end to a rotatable fluid coupling connected to the outboard portion of the arm.

5. The articulated fluid loading arm and support, as claimed in Claim 1, wherein a second horizontal pipe is connected at one end to an elbow end of the inboard portion of the arm and extends across an articulated joint connecting the outboard section of the support to the inboard section, the second end of the second horizontal pipe connected to a rotatable fluid coupling connected to the outboard portion of the arm.