IL30310A - Seal for a tank for storing liquids - Google Patents

Description

SEAL FOR A TANK FOR STORING LIQUIDS 0·»>Τ"Ι3 Γ 0ηβ> >3Ό> ΙΛΪΙ Ο 30310/3 The present invention relates to sealing structure for storage tanks and particularly to sealing structures for covered tanks for storing liquids, such as petroleum products, having therein a floating roof.

The present Invention provides a sealing structure for a tank for storing liquids such as petroleum products, said tank including an upstanding substantially cylindrical side wall, and a floating roof arranged within said tank aide wall and including an upstanding substantially cylindrical wall structure spaced radially inwardly from said tank aide wall and defining an upstanding substantially annular apace therebetween! eald sealing structure comprising a substantially annular sealing element edapted to be arranged in said annular space and carried by aaid roof wall structure and movable therewith wicb respeet to said tank aide wall, aaid sealing element having a flexible and resilient body having one portion adapted to be disposed adjacent to eald cylindrical wall structure, seid body having top and bottom walls tapering toward a bearing surface edapted to be disposed in sliding sealing engagement with said tank side wall, a first mounting flange integral with the inner edge of seid top wall and extending downwardly along the inner surface of said wall structure, a second mounting flange integral with eald bottom wall and extending along the outer surface of said roof wall structure and parallel to said first mounting flange and faetener means adapted to interconnect said first and second mounting flangeβ and said roof wall structure to mount eald wall structure with tha bearing surface of aaid sealing member diapoaed in eliding sealing engagement with aaid tank aide wall.

According to a further embodiment of the invention the sealing element may include a reinforcing web interconnecting the top and bottom walla intermediate the ends thereof and being diapoaed generally parallel to the mounting flangea.

The faatener means ma include a clamp bar disposed adjacent to the outer surface of the second mounting flange and carrying a plurality of threaded openings therein in register with aligned holes in the mounting flangea and the roof wall structure, and a corresponding plurality of bolts extending through the aligned holea and engaging the threaded openings to mount the sealing member upon the wall structure.

The eealing element may be formed of a plurality of extruded aectiona of resilient synthetic organic plaatlo resin, the preferred resin being a copolymer of butadiene and acrylonltrile resins.

The invention* both as to its organization and method of operation, together with further features and advantages thereof, will beat be understood by reference to the following specification, taken in connection with the accompanying drawings, in which* Figure 1 is a view in vertical section through a covered tank having therein a floating roof provided on the periphery thereof with a sealing structure made in accordance with and embodying the present invention], and Figure 2 is an enlarged fragmentary view in vertical section of that portion of Figure 1 within the circle designated by the numeral 2, and illustrating the details of construc-tion of the sealing structure of the present invention.

Referring now to Figures 1 and 2 of the drawing, there is illustrated a tank 10 for storing liquids, such as petroleum products, that includes an upstanding substantially cylindrical side wall 11 mounted upon a suitable base 12 and carrying on the upper portion thereof a covering roof 13 that is generally conical in shape and extends outwardly beyond the side wall 11 and is provided with the usual manhole 14 therein, the manhole 14 being provided with the conventional cover 15. The tank 10 further comprises the usual outlet fixture 16 and 8 plurality of posts 17 which serve to support the covering roof 13 and also serve as guides for vertical movement of a floating roof 20 disposed within the tank 10.

The floating roof 20 is generally annular in shape and of piston-like construction, and as illustrated is arranged in the tank 10 in floating. relation with the stored liquid therein indicated at 18; whereby the floating roof 20 rises and falls with respect to the side wall 11 of the tank 10 in accordance with the head of the body of liquid 18 stored therein. As illustrated, the floating roof 20 is of the pan type and comprises structure defining a float 22, the float 22 being formed by a substantially flat circular plate 25 and an outer upstanding annular rim 26 with an inwardly directed flange 24, the parts 24 and 25 and 26 being suitably secured together, as by welding, to provide a structure that constitutes the float 22 that is adapted to float upon the surface of the liquid 18 within the tank 10. The annular rim 26 further includes an annular rim portion 27 disposed above the flange 24 and having an outer upstanding annular surface 28 and an inner upstanding an-nular surface 29. As illustrated, the outer annular surface 28 of the rim 27 is spaced radially Inwardly from the tank side wall 11, and specifically the inner surface 19 thereof, to define an annular space therebetween extending completely around the floating roof 20.

The annular rim 27 on the floating roof 20 carries sealing structure including a sealing element 30 comprising a substantially annular resilient member arranged in the annular space between the walls 19 and 28 and located principally above the level of the stored liquid 18. The sealing element 30 more specifically comprises a body of flexible and resilient material, the preferred material being an expanded synthetic organic plastic resin, such for example as a copolymer of butadiene and acrylonitrile resins, suitable resins being that sold under the trademark "Buna N" or that sold under the trademark "Rubatex", or the equivalent.

Preferably the sealing element 30 is formed as a continuous extrusion of the resin shaped to provide a top wall 31 and a bottom wall 32 that converge radially outwardly and provide a thickened juncture 33 having a bearing surface 35 that is disposed in sliding . sealing engagement with the tank side wall 11 and specifically the inner surface 19 thereof.

Since the completed sealing element 30 is actually annular in shape, relatively short sections having the extruded shape of Figure 2 are cemented in place during the construction of the tank 10 In the field to provide a continuous annular ring which at any point has a cross section along a diameter of the tank 10 of the shape generally illustrated in Figure 2. It will be understood that before engagement of the bearing sur-face 35 with the tank side wall 11, the top wall 31 of the sealing element 30 Is arranged substantially horizontally, while the bottom 32 extends outwardly and upwardly toward the juncture 33 with the top wall 31. The top wall 31 extends radially inwardly and over the upper edge of the rim.27 and carries on the inner edge thereof a first mounting flange 36 which is disposed substantially normal to the top wall 31 and extends downwardly along the inner surface 29 of the rim 27. The inner edge of the bottom wall 3 carries a second mounting flange 37 integral therewith and extending upwardly therefrom, the mounting flange 37 being disposed against- the outer surface 28 of the rim 27 and substantially parallel to the first mounting flange 36 and disposed in lateral alignment therewith. The sealing element 30 further comprises a pair of spaced-apart webs 38 and 9* the web 38 being disposed outwardly toward but spaced from the juncture 33 between the walls 31 and 32 and substantially normal to the top wall 31 , while the reinforcing web 39 Is disposed toward but spaced from the mounting flanges 36-37 and -is also disposed substantially normal to the top wall 31 . The reinforcing webs 38 and 39 provide a desired degree of rigidity in the sealing element 30 and in effect provide a relatively stiff body having on the outer annular edge thereof the bearing surface ' 35 and having on the inner annular edge thereof the mounting flanges 36 and 37.

Fastener structure is provided to mount the sealing element 30 upon the wall structure comprising the rims 26-27 of the floating roof 20 so as to hold the bearing surface 35 of the sealing member 30 disposed in sliding sealing engagement with the tank side wall, thus to seal the annular space between the tank side wall 11 and the rim 26 above the surface of the stored liquid l8„ To this end aligned holes are provided et regular intervals through the rim 27 and the mounting flanges 36-37. There is provided against the outer surface of the mounting flange 37 a clamp bar 40 having opening therein in alignment with the holes in the flange 37 and with threaded nuts 4l arranged in registry with those holes. A washer bar is provided against the inner surface of the mounting flange 36 and having openings therein in alignment with the holes in the flange 36, the washer bar 5 having a plurality of washers 46 suitably secured thereto as by welding and having openings therein in alignment with the openings in the washer bar 45. Finally, there is provided a bolt 50 having a threaded shank 51 pointed at one end as at 52 and carrying on the other end the usual hexagonal head 53, the shank 51 of the bolt 50 extending through the aligned openings in the associated washer 46 and the washer bar 45, and through the associated aligned holes in the rim 27 and the mounting flanges 36-37, and through the associated opening in the clamp bar 40 and threadedly engaging in the associated nut 4l on the clamp bar 40. In this manner, the bolt 50 serves to clamp the mounting flanges 36 and 37 against the rim 27 and between the clamp bar 40 and the washer bar 45. It will be understood that the clamp bar 40 and the washer bar 45 are formed as generally rectangular pieces of metal that are then curved to conform to and to have a radius of curvature substantially equal to the radius of curvature of the rim 27, preferably the bars 40 and 45 having convenient lengths, such as for example 3 feet whereby a plurality of the bars 40 and 5 is provided around the periphery of the floating roof 20, the nuts 4l and the washers 46 preferably being disposed approximately every 9 Inches t erealong.

In the construction of the floating roof 20, and specifically in the mounting of the sealing element 30 thereon, the pointed ends 2 of the bolts 1 can actually be forced through the mounting flanges 36-37, whereby it is necessary to drill holes only in the rim 27, the clamp bar 40 and the washer bar 4 being pre-assembled elements with the necessary holes already drilled therein prior to transport to the site for assembly of the tank 10. The clamp bar 40 can be easily inserted into its operative position by virtue of the cross section of the. sealing element 30. As a result, the labor required to assemble the sealing element 30 onto the floating roof 20 is minimized thus to provide a structure that can be inexpensively assembled.

It will be appreciated that the sealing element 30 provides a good seal between the tank side wall 11 and the rims 26-27 due to the cross section thereof, the cross section being substantially wedge-shaped with additional rigidity provided where needed by the reinforcing webs 38-39. As a conse-quence, the sealing element 30 has a good service life, while being inexpensive to manufacture and assemble onto the floating roof 20.

In a preferred constructional example of the sealing element 30, the distance between the bearing surface 35 and the Inner surface of the mounting flange 36, i.e., the overall length of the top wall 31, is 9 inches (about 22 cm.); the thickness of the top wall 31 and the bottom wall 32 is inch (about 0.6 cm.); the thickness of the reinforcing webs 38-39 is £ inch; the thickness of the mounting flanges 36-37 is 3/8 inch (about 1 cm.); the vertical extent of the bearing surface 35 is 3/8 inch; the vertical extent of the mounting flange 36 is l 3/4 inches (about 4. cm.); the outer surface of the reinforcing web 38 is disposed 2£ inches (about 5.7 cm.) from the juncture of the walls 31 -32; and the distance between the outer surface of the mounting flange 37 and the inner surface of the reinforcing web 39 is 2 3/8 inches (about 6 cm.).

Prom the above it will be seen that there has been provided in a covered tank for storing liquids, such as petro-leum products, and including a floating roof, an improved sealing structure for the annular space disposed between the upstanding annular side wall of the tank and the upstanding annular rim of the floating roof.

While there has been described what is at present considered to be the preferred embodiment of the invention, it will be understood that various modifications may be made therein within the spirit and scope of the invention.

Claims (8)

1. A sealing structure for a tank for storing liquids such as petroleum products, said tank including an upstanding substantially cylindrical side wall, and a float¬ ing roof arranged within said tank side wall and including an upstanding substantially cylindrical wall structure spaced radially inwardly from said tank side wall and defining an upstanding substantially annular space therebetween; said sealing structure comprising a substantially annular sealing element adapted to be arranged in said annular space and carried by said roof wall structure and movable therewith with respect to said tank side wall, said sealing element having a flexible and resilient body having one portion adapted to be disposed adjacent to said cylindrical wall structure, said body having top and bottom walls tapering toward a bear¬ ing surface adapted to be disposed in sliding sealing engagement with said tank side wall, a first mounting flange integral with the inner edge of said top wall and extending downwardly along the inner surface of said wall structure, a second mounting flange integral with said bottom wall and extending along the outer surface of said roof wall structure \ and parallel to said first mounting flange and fastener; means adapted to interconnect said first and second mounting flanges and said roof wall structure to mount said /sealing member upon said roof wall structure with the bearing surface of said sealing member disposed in sliding sealing engagement with said tank side wall. \ . . 30310/2

2. A sealing structure according to claim 1, wherein the top wall and the bottom wall converge outwardly and terminate in a juncture providing said bearing surface, said first mounting flange being integral with the inner edge of said top wall and said second mounting flange being integral with said bottom wall, and a reinforcing web interconnects said top and bottom walls intermediate the ends thereof and disposed generally parallel to said mounting >' flanges.

3. A sealing structure according to claim 2, wherein two reinforcing webs are, provided interconnecting said top and bottom wall at intervals therewith, 1 said reinforcing webs being spaced apart and spaced inwardly from said edges of said top and bottom walls and disposed substantially parallel to said mounting flanges.

4. A sealing structure according to claim 2 or 3, wherein said top wall is arranged substantially horizontally and said bottom wall extends radially outwardly and upwardly with respect to said roof wall structure, and said mounting flanges .and said reinforcing web eire disposed substantially normal to said top wall.

5. A sealing structure according to any of claims 1 to 4, wherein the fastener means including a clamp bar disposed adjacent to the outer surface of said second mounting flange and carrying a plurality of threaded openings therein to register with aligned holes in said first and second mounting flanges and said roof wall structure, and a correspond 30310/2 and engaging said threaded openings to mount said sealing member upon said roof wall structure.

6. A sealing structure according to any of claims 1 to 5, wherein the sealing element is formed of a plurality of extruded sections of expanded resilient synthetic organic plastic resin.

7. A sealing structure according to claim 6, wherein said synthetic organic plastic resin is a copolymer of butadiene and acrylonitrile resins.

8. A sealing structure substantially as herein described with reference to the accompanying drawings. S. HOROWITZ & CO. AGENTS FOR APPLICANTS