US3154214A - Roof drain for floating roof tank - Google Patents

Description

Oct. 27, 1964 c. E. BAKER ROOF DRAIN FOR FLOATING ROOF TANK 3 Sheets-Sheet 1 Filed July 25, 1962 3/ on 2 9k mm mm on 3 lllli z mm mmoz =m Swoonv. 2 L 2 EE m 9 9k Fm 3 INVENTOR. C. E. BAKER BYWWW ATTORNEYS Oct. 27, 1964 c. E. BAKER 3,154,214

ROOF DRAIN FOR FLOATING ROOF TANK Filed July 25, 1962 3 Sheets-Sheet 2 INVENTOR. C.E. BAKER M ff A 7' TURNED S Oct. 27, 1964 c. E. BAKER ROOF DRAIN FOR FLOATING ROOF TANK 3 Sheets-Sheet 3 Filed July 25, 1962 TO PIPE FIGS INVENTOR. C.E. BAKER ATTORNEYS United States Patent 3,l54,2l4 ROOF ERAEN FOR FLOATELJG ROOF T Carl E. Baker, Kansas tl'ity, Kana, assigns;- to Phillips Petroleum Company, a corporation of Delaware Filed July 25, 1952, Ser. No. 2,403 7 Claims. (Cl. Mil-26) This invention relates to floating roof storage tanks. In one aspect it relates to a drain system for disposal of water from the floating roofs of floating roof storage tanks.

Various types of floating roof liquid storage tanks are known in the art. For the most part these tanks comprise a generally cylindrical upright wall having a floating roof which is supported by the liquid in the tank. The peripheral edge of the roof is provided with a suitable sealing means that slides up and down the inner surface of the tank wall as the roof rises and falls due to variations in the level or" the liquid in the tank. It is, of course, apparent that the roof cannot engage the wall so closely as to prevent movement of the roof in response to changes in liquid level.

Obviously, rain water must not be allowed to accumulate on such roofs. Disposal of such water is a problem because of the movement of the roofs up and down as the tanks are filled and emptied.

In order to prevent leakage of water into the tank at the periphery of the floating roof it is general practice to position a sump near the center of the roof at the lowest point thereon to collect water. This sump is, in turn, connected to a drain outlet near the bottom of the tank. Since the roof is movable, the means connecting the sump with the drain outlet must be sufllciently flexible to allow movement of the roof. One drainage system that has been used heretofore employs a jointed metal drainage pipe assembly which is connected at one end to the sump and at the other end to an outlet near the bottom of the tank. The joints of these metal drainage pipes frequently are swivel joints. However, such joints have been a source of trouble and often develop leaks which necessitate frequent repairs. A problem is presented because workmen cannot enter the tank until it has been sufliciently vented to remove toxic vapors and gases the removal of which is, of course, costly and time consuming.

Another drainage system that has been used comprise a long, flexible conduit attached at one end to the sump at the roof and at the other end to an external drain outlet. While this system eliminates several of the difliculties inherent in the jointed pipe system, it has not been entirely satisfactory from a maintenance standpoint. Occasional repair and replacement of the flexible conduit is required. The procedure that has generally been followed in replacing this flexible conduit has been to connect one end of a line to the upper end of the conduit near the sump and to withdraw the conduit from the tank through the drain opening in the wall. The line is then attached to a new conduit which is drawn into the tank through the drain opening. This system, however, requires a crew of workmen operating on the roof of the tank as well as a crew on the ground. In case the flexible conduit has broken at a point within the tank, such a procedure cannot be followed and the tank must be completely emptied and freed from toxic and explosive vapors.

An object of this invention is to provide a water drain system for a floating roof tank which is simple in operation and requires a minimum of maintenance. Another object of this invention is to provide such a drain system having flexible joints which, during rising and lowering of the roof, bend or flex only slightly. Still another object of this invention is to provide such a water draw system in which he flexible joints carry substantially no weight. Still other objects and advantages of this invention will he realized upon reading the following description which, taken with the attached drawing, forms a part of this specification.

in the drawing FIGURE 1 is an elevation View, partly in section, of a floating roof tank illustrating the assembly and operation of the drain system of this invention. FEGURES 2, 3 and 4 are isometric views of portions of the apparatus illustrated in FIGURE 1. FIGURES 3a and 4a are side views of a portion of the apparatus of FIGURES 3 and 4, respectively. FIGURE 5 is a portion of the apparatus of FlGURE 1.

The drain system of this invention comprises, broadly, a plurality of pipes one of which is connected with the sump in the roof of the tank and the remaining pipes lead prog essively from this first-mentioned pipe to the outlet pipe in the wall of the tank near the bottom. Each pair of adjacent pipes is connected with one or more flexible conduits so arranged that these flexible conduits need never to bend more than a relatively few degrees, i.e., none of these flexible conduits need ever bend even as much as 45-degrees.

Referring now to the drawing, and specifically to FEGURE 1, reference numeral 11 refers to a conventional tank, partly in section, having a floating root 12 positioned near the top of the tank. The tank is illustrated as being substantially full of liquid. A drain line assembly 13 is positioned in this tank according to this invention. The water inlet end of the drain line assembly is connected with well or sump 14 at the center of the floating roof l2 and water from this sump then will flow through pipes 55, 5d, 53, 52 and thence from the tank through pipe 2'7. Each of these several just-mentioned pipes are usually ordinary steel pipes. Connecting pipes 54 and 55 and connecting pipes 52 and 27 are flexible conduits or flexible conduit assemblies illustrated in FIGURE 2 and identifled by reference numeral 15. Connecting pipe 54 with pipe 53 is a flexible connection 17 and illustrated in detail in FIGURE 4. Connecting pipes 53 and 52 is a flexible connection 16 and illustrated in detail in FlGURE 3.

On reference to FIGURE 2 the flexible connection 15 connects pipes 52 and 27. A flexible tube 51 comprises, for example, a neoprene tube surrounded by a woven metal protective cover. This flexible tubing assembly is provided with flanges 2d and 25 on the ends thereof for attaching to pipe flanges. Pipes 27 and 52 are provided with flanges which are backed up by plates 13 and channel irons 18a.

The ends of these members, that is, the plates and channel irons, are welded to T- irons 19, 21, as illustrated. The T-irons 2 3. are illustrated as being attached to the structural members adjacent pipe 52 while T-irons 19 are illustrated as being attached to the plate and channel irons attached to pipe 27. A bearing plate 29 is attached to the end of each T-iron 19 while a bearing plate 22 is attached to each end of the T-irons 21 as illustrated. Each of these bearing plates has a hole through it for accommodation or" a bolt or pivot 23. Two of these bolts or pivots 23 are required because of the presence of the flexible tubing 51 between the support side members. The bolts are held in position by a pair of lock nuts in a conventional manner.

As illustrated in FIGURE 1, the flexible joint member 15 need not be bent or flexed through a very sharp angle. in fact, the angle is ordinarily not more than a maximum of 25 to 30 degrees.

The flexible joint member 15 which connects pipes 54 and 55' is just exactly like the member just discussed relative to the connection between pipes 27 and 52.. As

3 illustrated in FIGURE 1, this upper flexible joint 15 will be bent at an angle of about 45 degrees from a straight angle when the roof of the tank is at its uppermost position.

These flexible connections may be termed flexible Us and when the upper flexible L 15 is bent or flexed through an angle of about 45 degrees from a straight angle, the L may be conventionally termed a l35-degree L or rather a 45-degree L. Thus, in the same manner the L 15 positioned at the bottom of the tank will be termed a 25- or 30-degree L.

On reference to FIGURE 3, which is an isometric view illustrating the construction of the flexible joint 16 of FIGURE 1, reference should also be made to FIG- URE 3a. FIGURE 3a comprises a pipe L 31, which, in the case of assembly 16, is a ISO-degree L, i.e., the acute angle between the axes is a 30-degree angle and the outside or obtuse angle being the remainder of 180 degrees or 150 degress. To each end of the pipe L 31 is attached fluid-tight a flexible tube 33 similar to the flexible tube 51 described relative to FIGURE 2. The ends of these flexible tubings remote from the pipe L are provided with flanges having openings for attaching to pipe flanges or the like. Welded to the side center of the L 31 is a slotted bar 32. A similar slotted bar is likewise welded to the back side of the L 31. These sloted bars are clearly illustrated in FIGURE 3. On reference to FIGURE 3, this flexible tube and L assembly is attached to the ends of pipes 52 and 53 in the same manner that the end of the flexible tube of assembly 15 was attached to its end of pipe 52. T-irons 34 are welded at one end to the plate 18 and channel iron 18a so that the T-irons are positioned parallel to the longitudinal axis of the pipe 53 and there is similar positioning of corresponding members parallel to the axis of pipe 52. Several bearing plates 35 are provided w'th openings through which a pivot or bolt 36 is inserted. This pivot 36 also is positioned through the slots in the slotted bars 32. The ends of the pivot 36 are threaded for accommodation of either lock nuts or lock Washers and ordinary nuts for maintaining the pivot permanently in its operable position. The lower T-iron supports along the sides of the flexible tubing 33 are identified in FIGURE 3 by reference numeral 37. The bearing plates attached to the lower T-irons 37 are identified by reference numeral 38. A spacer rod 39 is welded to the mutually facing sides of the bearing plates 35 to maintain the side assemblies rigidly spaced from one another with ample room between them for accommodation of the flexible tubes and pipe L.

As will be realized, upon increasing the angle between pipes 52 and 53, the slotted bar 32 will move from right to left in FIGURE 3 and, conversely as pipe 53 approaches pipe 52 with the angle therebetween becoming smaller, the slotted bar 32 will move from left to right. As mentioned hereinabove relative to the flexible assemblies 15, this flexible assembly 16 will provide for flexing of the flexible members 33 only through relatively small angles and, at the same time, allow the pipes 52 and 53 to become separated by a relatively large angle.

The flexible assembly 17, illustrated in perspective in FIGURE 4, is constructed along the same general lines as assembly 16. This assembly 17 is provided with side T-irons 40 and slotted bearing plates 41 having elongated slots 47. The slotted bearing plates 41 differ from the bearing plates of FIGURE 3 since the plates of FIGURE 3 contained merely a circular opening for accommodation of pivot 36. The plates 41a contain only circular openings for pivot 36. On reference to FIGURE 4a, the construction of the flexible joint member is illustrated. This flexible member comprises flexible tubes 44 similar to the corresponding tubes 33, mentioned hereinbefore. L 43 is, in this case, a l60-degree L which provides an acute angle of 20 degrees between the axes of the ends thereof. A slotted plate 46 is constructed somewhat diflerent from the corresponding slotted bar illustrated in FIGURE 3a. This slotted plate 46 is provided with a more or less rectangular slot of considerable area. This slotted plate is welded to one side of the L 43 while a similar slotted plate is attached by welding to the opposite side of L 43. The positioning of these two slotted plates 46 is clearly shown in FIGURE 4.

A pivot 45, threaded on both ends or it can be a bolt, is inserted through the openings in the several bearing plates 41, 41a, and through the rectangular openings in the slotted plates 46. As the ends of tubes 44 open or close the angle between them, pipe 54 with its end support T-irons 40 and bearing plates 41 can move longitudinally with respect to the pipe by reason of slots 47 in the bearing plates 41. To accommodate this movement and still maintain the pipe L 43 in a proper position, the utility of the rectangular openings in the slotted plates 46 becomes apparent. While the bearing plates 41 are provided with slotted openings, the bearing plates 41a are provided merely with circular openings. Thus, the pivot 45 will remain in a definite position in the openings in bearing plates 41a while bearing plates 41 and pipe 54 can move axially with respect to the pipe.

The pipe 55 is attached to the wall of well 14 by flanges or means not shown. A support Y-member 49, FIGURE 5 is supported through the roof of the tank by a flange or nuts attached to the upper end thereof or by other means if desired.

The Wall outlet assembly 26, through which pipe 27 extends, is illustrated in detail in FIGURE 1, this assembly, for illustrative purposes, comprises a short section of a relatively large diameter pipe 29 having a flange 55 on its outer end mating with a flange 28 through which the outer portion of pipe 27 extends. Any means desired can be employed for supporting pipe 29 in the wall of the tank. This type of assembly illustrated is merely for exemplary purposes. A support 30 can be merely a pair of vertical pipes attached to the bottom of the tank and across the top ends of which is a member on which pipe 27 can rest.

A chain 50 of predetermined length is attached by a pair of eyes or links welded to the respective pipes 53 and 54 as illustrated. This chain limits the angle of opening of elbow assembly 17 and allows pipe 54 to carry the weight of pipes 52 and 53 rather than the joint or pivot of elbow assembly 17.

In the assembly for water draining purposes as herein described, FIGURE 1 illustrates this assembly when the tank roof is substantially at the top of the tank. When the tank roof is at the bottom of the tank, the several pipes, that is, pipes 27, 52, 53, 54 and 55, are all parallel to one another in a fully folded condition. In order that pipe 53 will not rest against pipe 52, a support rest 48 is welded to the upper surface of pipe 52 at about the position illustrated in FIGURE 1. This support or rest 48 has a small plate across its top on which pipe 53 rests.

While the several flexible tubes 33, 44, 51, have been hereinabove mentioned as comprising neoprene tubing surrounded by woven metal cloth for protective purposes, these flexible tube members can also be metal hose assemblies. When they are flexible hose assemblies, they .are such as those described in Volume II, Thomas Register, Thomas Publishing Co., New York City, as illustrated on pages 3567 through 3573.

Such an assembly as herein disclosed has been used in a large oil refinery tank for a considerable period of time and has been found completely satisfactory without any failure whatever.

One assembly of such a. drain system has been previously constructed and installed outside of a tank and the upper end raised and lowered a suflicient number of times corresponding to about two years of use and the assembly operated in a fully operable condition and no failure whatever occurred during this simulated time test. In these cases the several pipes 27, 52, 53, 54 and 55, were 3-inch diameter pipes, the several Us and the flexible tubings 33, 44, 51 were also 3-inch diameter. Thus, the entire assembly was a 3-inch diameter assembly which has been found suitable for easy and rapid removal of water from the roof of a large tank during even the heaviest of rainfalls.

That which is claimed is:

1. A flexible joint conduit assembly comprising, in operable combination, an L conduit, the longitudinal axes of the ends of said L conduit making a predetermined angle with each other, a separate fleiL'ble tubular member being attached fluid-tight at one end of each to opposite ends of said L conduit, separate pipes connected fluidtight at one end of each to the respective other ends of the flexible tubular members, a pair of opposed rigid supports attached at one end of each to the opposite sides of the end portions of said separate pipes adjacent the fiexible tubular members and extending along the flexible tubular members and terminating beyond said L conduit, a slotted plate attached at one end rigidly to said L conduit, an opening in each of the ends of the rigid supports adjacent said L conduit, and a pivot extending through the slot of said slotted plate and through the openings in the ends of said rigid support, said pivot being the apex of said flexible joint as the end of one of said pipes is moved with respect to the corresponding end of the other of said pipes.

2. A roof drain conduit for a floating tank roof comprising, in operable combination, a first pipe communicating at one end with a roof drain well and the other end being positioned below said roof, a second pipe, a first flexible conduit connected at one end fluid-tight to said other end of said first pipe and at the other end to one end of said second pipe; 21 first flexible L comprising a second flexible conduit connected at one end with the other end of said second pipe, a first pipe L connected at one end with the other end of said second flexible conduit, a third flexible conduit connected at one end with the other end of said first pipe L; a third pipe connected at one end with the other end of said third flexible conduit; a second flexible L comprising a fourth flexible conduit connected at one end with the other end of said third pipe, a second pipe L connected at one end with the other end of said fourth flexible conduit, a fifth flexible conduit connected at one end with the other end of said second pipe L; a fourth pipe connected at one end with the other end of said fifth flexible conduit, a sixth flemble conduit connected at one end with the other end of said fourth pipe, a fifth pipe connected at one end with the other end of said sixth flexible conduit and the other end extending to the exterior of the tank; said other end of said first pipe, said one end of said fifth pipe and both ends of each of said second, third and fourth pipes having extension members rigidly attached thereto extending be yond said ends of said pipes, ends of said extension mernbers adjacent each other having a pivot thereby forming a flexible joint in such a manner that the axes of said first, second, third, fourth and fifth pipes are mutually parallel when the tank roof is in its lowermost position, first support means attaching the pivot at said first flexible conduit to the tank roof, second support means positioned below said one end of said fifth pipe, a separate slotted bar rigidly attached to each pipe L, said pivot passing through the slot of the adjacent bar, and a flexible connecting means of a predetermined maximum length attached to said second and third pipes, this latter means being adapted to limit the maximum angle between said second and third pipes.

3. The roof drain conduit of claim 2 wherein the angle between the axes of said first pipe L at the ends thereof is less than the maximum angle between the axes of said second and third pipes, and the angle between the axes of said second pipe L at the ends thereof is less than the maximum angle between the axes of said third and fourth pipes when the roof is at its uppermost position in its tank.

4. The assembly of claim 1 wherein the openings in the ends of the pair of supports on one of said pipes are slotted to impart additional flexibility to said joint.

5. The assembly of claim 1 wherein said supports comprise longitudinal bars extending parallel with their respective pipes and bearing plates on each pair of plates extending toward the opposite bars, said plates overlapping each other, and the openings for said pivot being in the overlapping portions of said plates.

6. The assembly of claim 1 wherein the slotted plate attached to said L conduit is provided with an elongated slot, the longitudinal axis of which passes thru said pivot.

7. The assembly of claim 1 wherein the slotted plate attached to said L conduit is provided with a relatively large substantially square slot to accommodate maximum movement of said joint.

References Cited in the file of this patent UNlTED STATES PATENTS 561,442 Schmidt June 2, 1896 1,129,308 Martin Feb. 23, 1915 1,138,281 Dodge May 4, 1915 1,857,362 Day May 10, 1932 2,359,723 Hammeren Oct. 3, 1944 2,717,095 Gable Sept. 6, 1955 FOREIGN PATENTS 585,775 Germany Oct. 9, 1933

Claims (1)

1. 2. A ROOF DRAIN CONDUIT FOR A FLOATING TANK ROOF COMPRISING, IN OPERABLE COMBINATION, A FIRST PIPE COMMUNICATING AT ONE END WITH A ROOF DRAIN WELL AND THE OTHER END BEING POSITIONED BELOW SAID ROOF, A SECOND PIPE, A FIRST FLEXIBLE CONDUIT CONNECTED AT ONE END FLUID-TIGHT TO SAID OTHER END OF SAID FIRST PIPE AND AT THE OTHER END TO ONE END OF SAID SECOND PIPE; A FIRST FLEXIBLE L COMPRISING A SECOND FLEXIBLE CONDUIT CONNECTED AT ONE END WITH THE OTHER END OF SAID SECOND PIPE, A FIRST PIPE L CONNECTED AT ONE END WITH THE OTHER END OF SAID SECOND FLEXIBLE CONDUIT, A THIRD FLEXIBLE CONDUIT CONNECTED AT ONE END WITH THE OTHER END OF SAID FIRST PIPE L; A THIRD PIPE CONNECTED AT ONE END WITH THE OTHER END OF SAID THIRD FLEXIBLE CONDUIT; A SECOND FLEXIBLE L COMPRISING A FOURTH FLEXIBLE CONDUIT CONNECTED AT ONE END WITH THE OTHER END OF SAID THIRD PIPE, A SECOND PIPE L CONNECTED AT ONE END WITH THE OTHER END OF SAID FOURTH FLEXIBLE CONDUIT, A FIFTH FLEXIBLE CONDUIT CONNECTED AT ONE END WITH THE OTHER END OF SAID SECOND PIPE L; A FOURTH PIPE CONNECTED AT ONE END WITH THE OTHER END OF SAID FIFTH FLEXIBLE CONDUIT, A SIXTH FLEXIBLE CONDUIT CONNECTED AT ONE END WITH THE OTHER END OF SAID FOURTH PIPE, A FIFTH PIPE CONNECTED AT ONE END WITH THE OTHER END OF SAID SIXTH FLEXIBLE CONDUIT AND THE OTHER END EXTENDING TO THE EXTERIOR OF THE TANK; SAID OTHER END OF SAID FIRST PIPE, SAID ONE END OF SAID FIFTH PIPE AND BOTH ENDS OF EACH OF SAID SECOND, THIRD AND FOURTH PIPES HAVING EXTENSION MEMBERS RIGIDLY ATTACHED THERETO EXTENDING BEYOND SAID ENDS OF SAID PIPES, ENDS OF SAID EXTENSION MEMBERS ADJACENT EACH OTHER HAVING A PIVOT THEREBY FORMING A FLEXIBLE JOINT IN SUCH A MANNER THAT THE AXES OF SAID FIRST, SECOND, THIRD, FOURTH AND FIFTH PIPES ARE MUTUALLY PARALLEL WHEN THE TANK ROOF IS IN ITS LOWERMOST POSITION, FIRST SUPPORT MEANS ATTACHING THE PIVOT AT SAID FIRST FLEXIBLE CONDUIT TO THE TANK ROOF, SECOND SUPPORT MEANS POSITIONED BELOW SAID ONE END OF SAID FIFTH PIPE, A SEPARATE SLOTTED BAR RIGIDLY ATTACHED TO EACH PIPE L, SAID PIVOT PASSING THROUGH THE SLOT OF THE ADJACENT BAR, AND A FLEXIBLE CONNECTING MEANS OF A PREDETERMINED MAXIMUM LENGTH ATTACHED TO SAID SECOND AND THIRD PIPES, THIS LATTER MEANS BEING ADAPTED TO LIMIT THE MAXIMUM ANGLE BETWEEN SAID SECOND AND THIRD PIPES.

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