US2829795A

US2829795A - Sealing ring for floating roof storage tanks

Info

Publication number: US2829795A
Application number: US454566A
Authority: US
Inventors: Frederick D Moyer
Original assignee: Chicago Bridge and Iron Co
Current assignee: Chicago Bridge and Iron Co
Priority date: 1954-09-07
Filing date: 1954-09-07
Publication date: 1958-04-08
Anticipated expiration: 1975-04-08

Description

April 8, 1958 F. D. MOYER 2,829,795 SEALING RING FOR FLOATING ROOF STORAGE TANKS Filed Sept. 7. 1954 ma i.

F. D. MOYER SEALING RING FOR FLOATING ROOF STORAGE TANKS Fii'd- Sept. 7,,1954" -April 8,1958

3 Sheets-Sheet 2 April 8, 1958 F. D. MOYER SEALING RING FOR FLOATING ROOF STORAGE TANKS Filed Sept. 7. 1954 3 Sheets-Sheet 3 I In: /0 I WWW/W" It 7 m I I. I1" z6 L Z9 I I I A5; I /\9- J 0 l I I 20- I I Z6 o] I I Q /2 I y M ::g: L 7 66/e7ZC %J@f/7 SEALING RlNG FGR FLUATING ROOF STGRAGE TANKS Frederick D. Meyer, hicago, llll., assignor to Qhicago Bridge & Iron Company, a corporation of Illinois Application September 7, 1954, Serial No. 454,566 3 Claims c1. 220-26) This invention relates to a sealing ring for a floating except for a small narrow annular strip around the roof adjacent the side walls of the tank. The tanks are not always perfectly round so that the roof does not fit like a piston in a cylinder, but is free to permit some movement. The space between the floating roof and the tank side wall is sealed against escape of product vapors or the entrance of foreign matter from above the roof.

The sealing is accomplished by providing a ring of flexible character supported from the roof so that it slides against the inside of the tank. This ring moves up and down with the roof. A fabric curtain extends from the ring to the roof so that it may seal the space and yet permit movement of the roof within the tank side walls.

The present invention is concerned with the specific ice Figure 3 is an enlarged fragmentary vertical view of a portion of the sealing ring illustrated in Figure 1;

Figure 4 is a fragmentary horizontal sectional view through the sealing ring taken substantially along line i4 in Figure 3;

Figure 5 is a fragmentary vertical sectional view through the sealing ring and adjacent structure taken substantially along line 5-5 in Figure 3; and

Figure 6 is a view similar to Figure 5 taken substantially along line 6-6 in Figure 3.

, While the preferred embodiment of the invention is shown herein as a sealing ring for use particularly in a riveted tank, very little change of the structure is required or need be made to use the same structure in a welded tank. The particular changes which would ordinarily be made will be mentioned hereinafter with reference to particular structure.

In Figures 1 and 2, the tank side wall 10 is shown merely as the plates which go to make up that side wall, and the sealing ring is shown in contact with the inside of the side wall. A floating roof 11 is shown within the tank in Figure 2, and it is removed from Figure 1 in order to illustrate the sealing ring.

The ring itself is made in sections including holding plates 12, which in Figure I extend in a section from the juncture 13 to one edge 14 of an intershoe seal 15. This section 12 includes a number of flexures 16 formed in the metal and defining shoes between adjacent flexures. These iiexures are more clearly illustrated in Figures 3 and 4 and comprise a loop portion of the metal material. Each looped flexure is sealed at its upper end by a neoprene plug 17 which prevents the travel of product vapors up through the flexure and out from under the floating roof.

In the sealing ring as adapted for use in a riveted tank,

- a pair of sections 12 of the holding plates are joined tocharacter of the ring which slides against the inside of the tank. in the past, it has generally been necessary to replace the sealing ring from time to time due to Wear that occurs in the normal course of tank operation. Such replacement was an expensive operation since the tank ordinarily had to be emptied and sometimes even steamed clean. It was often costly .to take the tank out of service to permit the repairs, whereas, in the present invention, the repairs can be made without taking the tank out of service. i

A further difliculty in the past has been one of having to provide different types of sealing rings for tanks which were of welded construction and other tanks which were made of plates riveted together. The inside of the welded tanks is relatively smooth compared with a riveted tank since in the former there are no overlaps of plates to accommodate the rivets as there is in the latter. With the present invention, a single standard may be adopted by the manufacturer of sealing rings which may be adapted quite easily for use in either riveted or welded tank structures.

A preferred embodiment of the present invention is illustrated in the accompanying drawings illustrating a sealing ring for use in a riveted tank structure, and in which: 7

Figure 1 is a fragmentary vertical view looking toward the sealing ring and tank shell from inside the storage tank;

Figure 2 is a fragmentary planview of a section of the sealing ring illustrated in Figure 1 showing the floating roof adjacent to the ring;

gether at the seam 13 so that, in effect, they are one. An intershoe seal 15 of fabric material joins spaced end portions 14 and 13 of adjoining composite sections 12 ofthe holding plates. This intershoe seal 15 of fabric thus permits considerable variation in the circumference of the holding plate ring to accommodate passage of the ring over laps in the tank side wall, rivets, and the accommodation of irregularities in the tank circumference.

The ring of holding plates is supported from the floating roof. In Figure 1, a number of spreader bars 19 are shown as connected to alternate shoes of the holder ring and these are connected to a supporting hanger 26. This hanger forms no part of the present invention, and it is suflicient here to mention that the hangers force the shoes outwardly against the side walls of the tank because of the action of the hanger arms and the weight 21, and at the same time permits the roof to move laterally within the tank without causing the ring to raise or lower on the side walls.

In the present invention, the actual wear surface is provided by an additional plate which is secured to the outer side of the holder plates. Each wear plate 25 has a body portion 26 which extends over practically the extent of the holder plate between adjacent fiexures 16, an inturned lower edge 27 and a similar inturned upper edge 28. These wear plates extend above the annular flexible fabric seal 29 which closes the space between the ring and the roof.

Referring particularly to Figure 3, it will be noted that the upper edge 28 of the wear plate extends above the clamp bar 36 which isused to secure the fabric 29 to the upper edge of the holder plates. A plurality of bolts pass through the clamp bar, the fabric and the holder plates to secure the fabric in place. The outer bolts 31 additionally pass through the wear plate 25 and comprise the only means for supporting the wear plate in position. It will be noted that these bolts are accessible from the upper side of the floating roof 11. This permits them to be removed for removal and replacement of the wear plate 25. The particular structure of the hanger illustrated permits the sealing ring to be pulled away from the wall of the tank by pressure which can be supplied by hand. Under these circumstances, the wear plates can be easily and quickly removed from the sealing ring and replaced.

The area of the intershoe seal requires special treatment. In Figures 3 and 4, it Will be noted that a wear plate 25a is measured by bolts 31a to the lefthand holder plate. This wear plate terminates at a vertical edge 32 which overlaps a similar plate 25b secured to the righthand plate. Plate 25b terminates at a vertical edge 33 to the left of the edge 32 of the opposite plate. These two plates thus slide one upon the other to present a continuous surface against the side wall of the tank opposite the intershoe seal 15. The fabric 29 extends over the top of the intershoe seal preventing the escape of vapors through this avenue.

In a welded tank where the plates of each course are butt welded in order to present a relatively smooth interior, the use of the intershoe seal would be dispensed with. In such instances, the flexures 16 in the holder plate are suflicient to allow distention and contraction of the ring ,accornmodating irregularities in the tank circumference. In other respects, the structure would be the same as described in detail herein. Thus, it is clear that very little change is required to convert the standard holder ring from the structure required in a riveted tank to one necessary in a welded tank or vice versa. The use of the present invention permits one standard sealing ring and permits the replacement of the part of the ring which is subjected to wear in a very simple manner. To make repairs and replacements does not require the removal of the tank from service as the wear plates may be removed from the top of the floating roof deck and new plates secured in position without difficulty. The wear plates may be secured to the holder plates in other ways; as for example, by hooks on the wear plates engaging a lower edge of the holder plates.

The foregoing detailed description has been given for clearness of understanding only, and no unnecessary limitations should be understood therefrom, for some modifications will be obvious to those skilled in the art.

I claim:

1. A sealing ring for sliding movement against the walls of a floating roof storage tank, comprising: a ring of holder plates having an upwardly extending portion adapted to be positioned adjacent the tank side wall about the floating roof, a plurality of flexures at spaced points in said ring permitting changes in the circumference of the ring to accommodate protrusions and out-of-roundness in the tank walls, means supporting said ring from the floating roof, a flexible annular seal extending from the upper portion of the ring to the roof, and a plurality of contiguous wear plates, each having a body portion extending upright and against the tank wall and an inturned edge at the bottom and top of the body portion, said wear plates extending around the entire wall and means removably securing each wear plate individually to the outer periphery of said ring of holder plates in side by side contiguous relationship.

2. A sealing ring as specified in claim 1 wherein the ring of holder plates is provided with one or more flexible seals extending upright and joining the ends of sections of said ring and said wear plates are secured to the plates on either side of said flexible seal and overlapping in sliding relation over said flexible seal to present a continuous wear surface over the area of the flexible seal.

3. A sealing ring for sliding movement against the walls of a floating roof storage tank, comprising: a ring of holder plates having a plurality of upright flexures thereinpermitting the ring to change shape in sliding over tank wall irregularities; means supporting said ring from the roof and yieldingly urging the ring outwardly toward the tank side wall; a plurality of contiguous wear plates each having a body portion and an inturned upper and lower edge, said wear plates extending completely around said ring; and means for removably securing each wear plate to the outer side of the holder plates with each plate having a width to extend generally over the area between adjacent flexures in the holder plates.

References Cited in the file of this patent UNITED STATES PATENTS 1,892,144 Griflin Dec. 27, 1932 1,979,657 Wiggins Nov. 6, 1934 2,586,813 Goldsby et a1. Feb. 26, 1952 U. S. DEPARTMENT OF COMMERCE PATENT OFFICE CERTIFICATE OF CORRECTION Patent No, 2,82%795 Frederick I), Meyer April 8, 1958 It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 3 line 13;, for "measured" read w secured Signed and sealed this lQth day of June 1958,

Attest:

KARL H; AJEINE Conmissioner of Patents