US2126996A

US2126996A - Storage tank

Info

Publication number: US2126996A
Application number: US718219A
Authority: US
Inventors: Andrew A Kramer
Original assignee: Individual
Current assignee: Individual
Priority date: 1934-03-30
Filing date: 1934-03-30
Publication date: 1938-08-16
Anticipated expiration: 1955-08-16

Description

A. A. KRAMER STORAGETANK Filed March 30, 1934 2 Sheets-Sheet l 1Z2 43 57 ||||||I|| [V 1 HIHHHHHH IIIHHIII 72/ I W56 44 58 22-2 20 26: 231- Aug. 16, 1938. A. A. KRAMR STORAGE TANK 2 Sheets-Sheet 2 Filed March 50, 1934 ATTORNEY Patented Aug. 16, 1938 UNITED STATES PATENT OFFICE 14 Claims.

My invention relates to tanks or tank-like members, and particularly to storage tanks.

It is a particular purpose of my invention to provide a tank made up of metal sections or sheets that is provided with welded seams or joints that is so constructed that no packing of any kind is required for said seams or joints between the sheets of which the walls of said tank are constructed. By walls is meant not only the side wall portion, but the bottom wall and the top wall or roof portion of the tank.

It is a particular purpose of my invention to provide a welded tank of the above mentioned character that is so constructed that the same can be erected more efiiciently and simply than has previously been the case, and which will be stronger than welded storage tanks made of the same gauge of metal, constructed by previously known methods.

It is a particular purpose of my invention to provide a tank of the above mentioned character that can be economically fabricated, can be quickly assembled, and which can be welded all at one time instead of one sheet at a time, as has been previously necessary.

It is another important purpose of my invention to provide a new and improved method of building a welded tank that comprises cutting, punching and fitting the sheets at the place of fabrication for quick assembly into a tank at the place of erection, and to so form the. sections or sheets comprising the tank that the same can be quickly erected into a tank so as to be firmly secured together without welding any of the joints or seams between the sheets or sections, then securing. said sections or sheets together at the place of erection by suitable securing means, the bottom, side walls and roof or deck of the tank being erected in this manner, the sections of the bottom being first secured together, the side walls being built up from said bottom, and the roof or deck being mounted in position on the side walls, and suitably centrally supported, and the sections thereof firmly secured together, and then after the complete tank has been thus assembled at the place of erection, the welding of the bottom, the sides and the roof can be proceeded with in any order desired, the complete welding operation being performed without any interruption inasmuch as all the parts that are to be welded together are placed in their proper positions and held there before any welding is begun. This saves much time and labor and proves to be a great economy in the building of such tanks,

The securing means that are provided for holding the sections or sheets comprising the tank together prior to welding, may be left in place, if desired, or may be removed and, if desired, the sheets may be welded together at the openings for the securing means after removal thereof.

Many advantages result from my improved new tank construction and method. Thus, by the improved method of constructing the bottom of my tank, hinging of the plates or sheets, forming said bottom, relative to each other is entirely prevented. Also the complete tank can be set up without first tack-welding the bottom of the tank from underneath. It is not necessary, if the bolts or other securing means are retained in place after the welding operation has been completed, to weld the under side of the bottom of the tank at the seams or joints at all. This makes it unnecessary to raise the bottom of the tank off the ground a substantial distance, as is necessary when such welding must be clone on the underneath side of the bottom.

The method of connecting the bottom of the tank to the side wall of the tank, whereby the bottom is caught so as to hold the same while welding the side wall and bottom to each other, not only does this, but also holds the seam close together for welding, and the preferred form of joint between the bottom and side wall forms a reinforcing chime for the bottom and the shell or side wall of the tank at the junction of said bottom and side wall.

In the preferred construction, the side walls of the tank are provided with flanged sheets and the flanges of the sheets are bolted together, or

held together by any other suitable securing means, prior to Welding, which not only has the advantage of providing a quick method of assembling the side wall portion of the tank, but the annular side seams formed when the seams or joints have been welded, stifiens the tank and holds it round and reinforces the seam against wind pressure. My improved side wall structure can be welded either inside or outside the tank, or both.

My improved tank construction also has substantially the same advantages as to quick assembly and the provision of a better weld than would otherwise be possible, in the roof thereof,

and furthermore my improved construction elimr inates the necessity of a reinforcing angle iron around the top of the side Wall of the tank, where said side wall joins said roof or deck,.this being particularly so in a tank of large size.

Other objects and. advantages of my invention will appear as the description of the drawings proceeds. I desire to have it understood, however, that I do not intend to limit myself to the particular details shown or described, except as defined in the claims.

In the drawings:

Fig. 1 is a vertical transverse sectional view through a portion of my improved tank, the same being partly broken away.

Fig. 2 is a fragmentary topplan view of the roof portion of the tank.

Fig. 3 is a fragmentary vertical sectional view taken substantially on the line 3-3 of Fig. 2.

Fig. 4 is a fragmentary vertical sectional view of the joint between the side wall and the topor roof of the tank. i

Fig. 5 is a fragmentary vertical sectional view through a horizontal joint in said side wall.

Fig. 6 is a fragmentary sectional view taken substantially on the line 66 of Fig. 1.

Fig. 7 is a fragmentary top plan view of the bottom portion of the tank, showing a portion of the side wall in horizontal section.

Fig. 8 is a fragmentary sectional view, taken on the line 88 of Fig. 7.

Fig. 9 is a fragmentary perspective view of a portion of the tank body.

Fig. 10 is a fragmentary vertical sectional view of a slight modification.

Fig. 11 is a fragmentary vertical sectional view of the joint between the roof and side wall of the tank in the form of the invention shown in Fig. 10.

Fig. 12 is a fragmentary! vertical sectional view through the horizontal joint between two adjoining sections in the form of the invention shown in Fig. 10.

Fig. 13 is an enlarged fragmentary section of a portion of the bottom showing a seam therein.

Fig. 14 is a similar section of a side wall seam showing a single circumferential weld and the bolt welded in place, and

Fig. 15 is a section similar to Fig. 14, showing the bolt removed and the bolt-holes welded shut.

Referring in detail to the drawings, my improved storage tank is shown in Fig. 1 as comprising a bottom 251, a side wall 2| and a roof, or deck, 22 supported by the side wall and by a central supporting member mounted on a post 23. Thevarious sections, or sheets, of which the tank is made up, are cut to the proper shape and bent to the shape required, where such bending is necessary, and punched with suitable openings for receiving bolts at the place of fabrication, and these sheet metal sections, or sheets, are then assembled and welded together at the place of erection.

Referring to Fig. 7 it will be seen that the bottom is made up of a plurality of sheets, or sections 24, that are generally rectangular in shape, and other sections, or sheets 24' that have a curved edge portion so as to form the curved outline of the periphery of the bottom adjacent the side wall of the tank. 'The sections 24 are provided with openings 25 that align with similar openings 25 in either a section or

sheet

24 or 24', as the case may be, when the sheets are arranged in overlapping relation, as'shown in Fig. 9. The sheets or sections forming the bottom, overlap both at their longitudinal and transverse edges, with the openings in said overlapping sheets aligning. In the erection of the bottom, the sheets or

sections

24 and 24' are arranged in proper relationshipto form said bottom, and fastening elements, such as the bolts 26, are inserted in the aligning openings of the overlapping sheets from the underneath side of said bottom, and nuts 2'! are tightened down on the bolts to firmly secure said overlapping sheets together. One of the joints of the bottom is shown in cross section in Fig. 8, while in Fig. 9 a fragmentary view, partly in section and partly in elevation, shows the manner in which the joints of the bottom are arranged. Thus the section 24! is shown as overlapping the section 242 and the section 243 longitudinally, while the section 242 overlaps the section 243 transversely. The fastening elements 25 extend through the aligning openings in the sheets 24! and 242, as well as through the aligning openings in the

sheets

242 and 243 and the aligning openings in the sheets 2M and 243. The bottom is completely assembled in this manner, and after this has been done the side wall is built up, beginning with the connection between the bottom row of side wall forming memebrs and the bottom.

It will be noted upon reference to Fig. 8 that the peripheral sections 24' of said bottom extend outwardly beyond the vertical portion of the side wall forming member 28, and that this side wall section 28 has a laterally extending flange 29 thereon, which extends in face to face relation to the curved peripheral edge of the bottom forming section 24', with which it may be associated, with an opening 30 in said flange aligning with an opening3l is said section 24". Fastening elements 32 are extended through the openings 3| and 30 that are in alignment when these sections are in assembled relation to each other, from the bottom upwardly, and the nuts 33 are applied thereto to firmly secure the bottom row of side wall forming sheets 28 to the periphery of the bottom of the tank.

The spacing of the openings in the

sheets

24, 24' and 28 is such that sufficient securing elements can be used to connect the various sections to each other, in the manner described above, so that the same will be fixed in position and will be supported sufficiently that the structure will stand up indefinitely, under all but the most unusual conditions, in an empty condition, so that welding of the seams can be done at any time desired after the complete erection of the tank, by use of the detachable securing elements, such as the bolts previously described, has been completed. The side wall forming sheets, or sections, 28 are preferably provided not only with the flange 29, but with a corresponding flange 34 along the opposite edge thereof, as shown in Fig.

1. The section 28 is preferably curved to the curvature that the wall is to have when the tank is completed. The next adjacent row of sections, or sheets, 28' is of similar shape except that the sections, or sheets 28 each have fianges 29' and 34 thereon, corresponding to the

flanges

29 and 34 on the sections 28.

In the form of the invention shown in Figs. 1 and 5, the'fianges 29 are shorter than the flanges 34, and the

sections

28 and 28 are arranged in the manner shown in Fig. 5 with the inner face of the section 28 spaced slightly outwardly beyond the inner face of the section 23 so as to provide a small ledge at the joint between

said sections

28 and 28. Also the flange 34 extends outwardly a short distance beyond the outer edge of the flange 29'. This is, of course, accomplished by the location of the holes 35 and 3G in the flanges 34 and 29' respectively, which align and which'receive the bolt-like fastening elements 3? having the nuts 38 provided thereon. Each horizontal seam, or joint, of the side wall is made in the manner shown inFig. 5, with the upper flange at each joint related to the lower flange at each joint in the manner shown in said figure. The purpose of this will be described below.

The adjoining ends of the sections 28 or 28', of any one of the circumferential-rows of sections, are provided with overlapping joints with bolt openings provided therein that align, one of said joints being shown in Fig. 6, said sections 28 hav ing the aligning openings 39 through which the bolt-like fastening elements 45 are passed, and the nuts 4| thereon to secure the vertical seams together in firm, fixed relationship, the fastening elements in the vertical and horizontal seams being used in sufficient number and in sufficiently closely spaced relation, to hold the side Wall erect under all but the most unusual conditions, for such a length of time, with the tank empty, of course, that the welding of the side wall portions of the tank and the bottom, can all be proceeded with at the same time whenever this may be convenient. The top row of sections 28" is made in a similar manner to the previously described sec-- tions, but if desired, the upper flange portion on each section 28 may be bent at a slightly oblique angle, this being indicated at 34" in Fig. 4, so that the deck sections will fit flat-wise thereon, the pitch of the deck, or roof, being taken into consideration.

The deck, or roof portion, of the tank is shown as being made up of a plurality of sections 42, which are shown as being segmental in character, and have the radial edges of adjoining sections overlapping, while the outer peripheral edges overlap the flange formed, collectively, by the flanges 34" of the sections 28", and the inner ends or edge portions thereof overlap the central supporting member 43, said central supporting member being made of any desired shape, but being shown as being a slightly cone shaped platelike member 43 with a peripheral flange 44, which is supported by means of the post-like member 23 entering a socket portion 45 at the center thereof, and having conical bracing means 46 secured to the sleeve 41 surrounding said post-like member 23, and to the top plate 43. The parts forming this central support may all be welded together, and in turn, welded to the post 23, the post 23 being mounted on the bottom 20 in a flanged sleeve 48, which is bolted to said bottom, as indicated at 49.

In the erection of this central support it is not necessary that the post 23 be welded to the central supporting unit until the other welding is done, but ordinarily the parts of this central supporting unit are all welded together at the place of fabrication and all that is necessary in the erection of the tank is to place this central supporting unit on the post-like member 23 and fasten the sections 42 thereto. The sections 42 are provided with rows of bolt receiving openings 58 along the radial edges thereof, and with bolt receiving openings adjacent the outer peripheral edge thereof, as well as bolt receiving openings 52 at the inner ends thereof. The bolt receiving openings 5| align with bolt receiving openings 53, in the flanges 34" and bolts 54 are passed therethrough, and the nuts 55 cooperating. therewith firmly secure the roof or deck sections 42 to the side wall portion 2| by securement to the flanges 34". The overlapping radial edges of the sections 42 have the bolt receiving openings 50 therein aligning with each other when the roof, or deck, is assembled and the bolt-like membars 56 provided with the nuts 51 are passed therethrough to secure the adjoining deck sections 42 firmly to each other in face to face relation at said joints.

If-desired, a stiffening flange or web portion 58 may be provided on one section 42 at each radial joint to form radial, beam-like members under said roof'integral with the roof, and this web portion. may be provided with a lateral bottom flange 58 to further stiffen this beam-like member at each radial joint in the roof or deck. The deck sections 42 are further secured to the central supporting member 43 by passing bolt-like members 56 through the openings 52 and the aligning openings 6 0 in the central supporting member 43, the bolts in combination with the nuts 51 firmly clamping said roof sections 42 to the central supporting member 43.

The tank is thus completely erected and secured together by the detachable securing means shown as being in the form of bolt-like members. and will stand up in such erected condition until it is desirable'to proceed with the welding of the various joints in the tank structure.

The welding may be proceeded with from any desired point and in any desired manner. It would probably be the customary procedure, however, to proceed with welding the bottom first. All of the joints are welded at the points where the edges of the overlapping sheets overlie the underlapping sheets, the longitudinal welds being indicated at 6| in Figs. '7, 8 and 9, and the transverse welds at 62. In the case of the bottom the bolts 26 and nuts 21 are welded in place,

a weld 63 being provided around each bolt and nut. Thus the bottom is made liquid-tight, without any gasket or packing at any of the joints, all sheets being welded in liquid-tight relation to the sheets with which the same are in engagement. to the section or sections 24, upon which it is mounted, and the central post-like member 23 may also be Welded at 65 to said flange or flanged sleeve 48. Also the bolt-like members 49 and the nuts provided thereon are welded to the flanged sleeve 48 so as to provide a liquid-tight joint between the bolts and nuts and the flanged sleeve, and between the flanged sleeve and the bottom of the tank. The use of the bolts 26 in securing the bottom sheets together, prior to welding avoids the necessity of blocking up the bottom to weld it, which requires raising the same to a high level and makes the lowering of the same to its final position a dangerous operation. The use of the bolts furthermore prevents any tendency of the sheets to hinge relative to each other at the joints, there being two points of securement of the sheets to each other at the seams, in spaced relation to each other, thus preventing any such hinging.

The sections 24' of the bottom are welded to the flanges 29' on the side wall forming sections 28 by a continuous liquid-tight weld 61 on the outside of the tank, and a similar continuous weld 68 may be provided, if desired, on the inside of the tank. The forming of the weld at the outside of the tank is facilitated by making the flange 29 shorter than the projecting portion of the bottom section 24' to which it is welded, thus leaving a corner in which a fillet-like weld can be made. Of course, a similar corner exists at the weld 68. The use of the bolts 26 and of the bolts 32 causes a very close face to face engagement of the

sections

24 and 24 with each other, and of the flanges 29 on the sections 28 and the Of course, the flange 48 is welded at 64 iii sections 24 with each other, at the point of welding, and thus makes it possible to provide a neater and tighter weld than would be otherwise the case.

If desired, the bolt-like members 32 can be left in place, or can be removed after this welding has been completed. If the inner weld 68 is provided, the removal of the bolt-like members 32 does not require any further welding operation. The use of the bolt-like members 32, if no weld 68 is made, serves to prevent hinging of the bottom and side wall members relative to each other, in addition to serving as a temporary securing means, and in that case the bolt-like members 32 must be left in position to serve this purpose. If the bolt-like members 32 are left in position, and no weld 68 is provided, these must be welded around their heads and around the nuts 33 to prevent any leakage. If the bolt-like members 32 are removed and no weld 88 is provided, it is necessary that the bolt openings 30 and BI be welded shut to avoid any possibility of leakage, this being even desirable where a weld B8 is provided, to make sure that the joint is liquid-tight.

In welding up the side wall 2| the horizontal seams are Welded, preferably, as shown in Fig. 5, there being a continuous external weld at 69, and a continuous internal weld at 10. After the welds 69 and 10 have been made the bolt-like members 3'! can be removed, and if preferred, the holes welded shut, as shown at 80 in Fig. 15, or the bolt-like members 31 can be left in place and a weld 8| made around the head of the bolt and a weld 82 around the base of the nut 38, and the nut 38 welded at 83 to the bolt 31 (see Fig. 14) to provide a liquid-tight joint between the

flanges

29 and 34 at said bolts. This welding of the bolts in place is not absolutely necessary where an internal weld I8 is provided, although it is obvious that if the weld I0 is omitted, this would be necessary. All the horizontal seams are welded in the same manner as the seam described.

The vertical seams in the side wall portion are made in the manner shown in Fig. 6, all the vertical seams being made in the same manner. The vertical seams are, preferably, welded externally at 'H and internally at 12, the welds running from one of the horizontal seams to the next horizontal seam and being made liquidtight. Said welds join the edge portions of the overlapping sheets with the body portions of the cooperating sheets at a point spaced from the edges thereof. The bolt-like members 40 can be removed after these welds have been made, but in this case it is a necessity that the openings provided for the bolts be Welded shut if the bolts are removed, while, if the bolts remain in place a weld must be made around the head of the bolt on the inside of the tank, and a weld is also, preferably, made around the bolt and nut on the outside of the tank.

The peripheral edge portion of the roof 22 and the side wall 2| are Welded together by continuous circumferential internal and external welds, indicated at I3 and 14 in Figs. 1 and 4. If the internal weld 14 is provided, as well as the external weld I3, the bolts 54 can be removed, if desired, after the welding has been completed Without doing any more welding on the joint, or if preferred, the bolt holes through which the bolts 54 were extended, can be welded shut. Also the bolts can be left in position just as they were prior to welding, or if preferred, a weld can be made around each bolt head, around each nut and at the point where the nut embraces the bolt on the upper side of the joint.

The radial joints between the deck sections 42 are also welded, an external weld l5 and an internal weld I6 being provided, running the entire length of the joint, as shown in Fig. 3, and in order to prevent escape of gases around the bolts 56, it is necessary, if the bolts 56 are not removed, to weld around the bolts and nuts in the manner previously described in connection with the bolts and nuts previously mentioned, such as those in the side wall of the tank, or if the bolts 58 are removed, to weld shut the openings through which said bolts had been passed. The same is true of the bolts that connect the inner ends of the sections 42 with the central supporting member 43. If these are left in place, welds are made around the bolts and nuts to prevent any leakage at this point, and if they are removed the holes are welded shut. A continuous external weld TI is provided at the inner edges of the sections 42, joining the sections 42 with the central supporting member 43, and an internal weld "I8 may be provided between said sections 42 and the flange 44 on the member 43, the securing members being, of course, left in place until these welds have been made. The securing members used at all of the joints, serve to firmly clamp the parts together for welding, and provide for a better and neater weld than if the sheets are not clamped as firmly together face to face as can be done by my improved method of building a tank. The securing elements, if left in place, further add to the strength of the joint at all points where the same are used, and are not harmful to the structure in any respect. It is only a question as to which would prove the most economical, as to whether the bolts are to be removed and re-used in the erection of another tank, or left in place on the tank on which the same were originally used.

It will be noted that, with the stepped arrangement of the joints in the side wall of the tank shown in Fig. 5, each circumferential joint has an offset therein on the inner face and on the outer face of the tank to provide a recess in which the weld is made. Also a similar recess is provided in the corner between the circumferential edges of the roof sections and the flanges of the top-most sections of the side wall, and between the circumferential edges of the bottom flanges of the bottom-most row of side wall sections and the laterally extending portion of the bottom of the tank on the outside thereof. In Figs. 10, ll. and 12 a modified form of tank is shown, in which there is no such a stepped arrangement at the joints. In Fig. 10 the flanges I28 on the bottommost sections I28 of the side wall of the tank are shown as terminating with their outer edges in alignment with the outer circumferential edge of the bottom I20 of the tank, a weld IG I being provided at said outer edges of the flange and bottom, respectively, the bolts 32 being utilized in the same manner as was previously the case and the weld 68 being provided in the same manner as was described in connection with the form of the invention shown in Figs. 1 to 9 inclusive. The flanges I29 and I34 at each of the circumferentially extending seams are made in the same manner, each having an external weld I61 at the peripheral edge portions of the flanges I29 and I34, which are made the same on both edges of all the sheets or sections comprising said side wall, and a weld I68 may be provided on the inner side of each joint, the adjacent surfaces of 'same purpose.

holes for the bolts welded shut, or the bolts and sections arranged in face to face relation, headed securing means extending through said flanges at .points spaced from the marginal edges thereof the sheets. at the bases of the flanges being welded together by means of this weld.

In-the form of the invention shown in Fig. 10, the uppenmost sections I28 may be made slightly different than the other sections by slightly inclining the upper-most flange I34 so as to correspond to the pitch of the deck sections 42, which are the same as previously described. The flanges I36 extend only as far laterally, however, as the circumferential edge portions of the deck or roof sections 42 and the weld "I is provided between these edge portions in the same manner as the welds I61 previously described. The weld M on the inside of the seam is the same as described in connection with Figs. 1 to 9 inclusive. The bolts 31 and A are used in the same manner as were these bolts in the form of the invention previously described and serve the The bolts may be removed, the

nuts welded in place, in this form of the inven tion just as could be done in the form of the invention previously described.

In either form of the invention, aside from the great economies and advantages in the building of a tank of this character, and the advantages of avoiding hinging of the sections of the bottom relative to each other and of the bottom relative to the adjacent side wall sections, the further advantage is obtained that the joint between the bottom and the side wall provides a reinforcing chime for the bottom and the side wall of the tank at this point. Also the annular or horizontal side seams stiffen the side wall and hold the tank round, reinforcing the tank against wind pressure and preventing the distortion of the tank due to wind pressure that usually occurs in large tanks that are made with welded, or riveted, or other similar joints. Also due to the joint between the roof and the side wall, any necessity for any angle iron reinforcement along the top of the side wall of the tank, in tanks of large diameter, is avoided.

What I claim is:

l. A unitary tank wall comprising flanged sheet metal sections having the flanges of adjoining sections arranged in face to face relation, headed securing means extending through said flanges at points spaced from the marginal edges thereof and clamping said flanges in close, face to face engagement, and a continuous weld integrally uniting the marginal edges of said flanges, said weld being spaced from said headed securing means.

2, A unitary tank wall comprising flanged sheet metal sections having the flanges of adjoining sections arranged in face to face relation, headed securing means extending through said flanges at points spaced from the marginal edges thereof andclamping said flanges in close, face to face engagement, a continuous weld integrally uniting the marginal edges of said flanges and a continuous weld integrally uniting said sections at the bases of said flanges, said welds being spaced from said headed securing means.

3. A unitary tank wall comprising flanged sheet metal sections having the flanges of adjoining sections arranged in face to face relation and welds integrally uniting said flanges at their marginal portions and at the bases of said flanges to secure said flanges in face to face engagement and provide a fluid-tight joint between said sections.

4. A unitary tank wall comprising flanged sheet metal sections having the flanges of adjoining and clampingsaid flanges in close, face to face engagement and a continuous weld integrally uniting said'sections at the bases of said flanges, said vweld being spaced from said headed securing means. 5. A unitary tank wallcomprising sheet metal sections having marginal perforated flanges with the flanges of adjoining sections arranged in face to face engagement with said perforations in alignment,a continuous weld integrally uniting said flanges in face to face engagement and means in'said aligning perforations welded to said flanges to integrally connect said flanges at points spaced from said continuous weld, whereby a fluid-tight joint is provided between said flanges.

6. A unitary tank wall comprising sheet metal sections having marginal perforated flanges with the flanges ,of adjoining sections arranged in face to face engagement with said perforations in alignment, headed securing means extending through said perforations in said flanges and clamping said flanges in close face to face engagement, a continuous weld integrally uniting said flanges, at a point spaced from said perforations and welds uniting said securing means with said flanges in fluid-tight relation. 7. A unitary, curved, vertical tank wall comprising curved sheet metal sections having flanges along a pair of opposite edges thereof extending .in the direction ofv curvature of said sections, the flanges of vertically adjoining sections being in face to face engagement, welds integrally uniting said flanges in such face to face engagement, said sections being arranged in rings in said wall with said flanges in alignment to form vertically spaced stiffening formations encircling said tank wall integral therewith, the adjoining sections of each ring having their adjoining marginal portions lapped and welds integrally uniting the lapped portions of said sections.

8. A unitary, curved, vertical tank wall comprising curved sheet metal sections having flanges along a pair of opposite edges thereof extending in the direction of curvature of said sections, the flanges of vertically adjoining sections being in face to face engagement, securing means extending through said flanges to clamp said flanges closely in face to face engagement, welds integrally uniting said flanges in such face to face engagement, said sections being arranged in rings in said wall with said flanges in alignment to form vertically spaced stiffening formations encircling said tank wall integral therewith, the adjoining sections of each ring having their adjoining marginal portions lapped, securing means extending through the lapped portions of said sections to clamp the same closely in face to face engagement, all said securing means being welded in position to provide a fluid-tight joint at said securing means and welds integrally uniting the lapped portions of said sections.

9. In a tank, the combination with an integrally welded bottom, of a vertical, curved, side wall comprising sheet metal sections secured in fixed relation to each other and each having an outwardly directed flange along the lower margin thereof, said side wall being integrally welded into a single unit, and a continuous circumferential weld integrally uniting said outwardly directed flanges with the marginal portion of said bottom to integrally unite said side Wall and said bottom.

10. In a tank, the combination with an integrally welded bottom, of a vertical, curved, side wall having an outwardly directed flange along the lower margin thereof, said side wall being integrally welded into a single unit and the marginal portion of said bottom extending outwardly beyond the vertical portion of said side wall, said flange overlapping said extending portion of said bottom, securing elements extending through said extended portion of said bottom and said flange and clamping said flange to the extended portion of said bottom closely in face to face relation and a continuous circumferential weld integrally uniting said outwardly directed flange with the extended portion of said bottom to integrally unite said side Wall and said bottom.

11. In a tank, the combination with an integrally welded bottom, of a vertical, curved, side wall having an outwardly directed flange along the lower margin thereof, said side wall being integrally welded into a single unit, a continuous circumferential weld uniting said bottom and said side wall adjacent the base of said flange, and a continuous circumferential weld integrally uniting said outwardly directed flange with the marginal portion of said bottom to integrally unite said side wall and said bottom.

12. In a tank, the combination with a substantially circular end wall of large area comprising sheet metal sections integrally welded together into a unit, of a substantially cylindrical side wall having an outwardly directed flange along the end margin thereof adjoining said end wall engaging face to face with the marginal portion of said end wall, said side wall comprising a plurality of flanged sheet metal sections circumferentially adjoining and integrally welded into a single unit, and a continuous circumferential Weld integrally uniting said outwardly directed flange with said marginal portion of said end wall to integrally unite said side and end walls.

13. In a tank, the combination with a curved vertical side wall having an outwardly directed flange along the top margin thereof, said side wall comprising a plurality of flanged sheet metal sections circumferentially adjoining and integrally welded into a single unit, of a top wall comprising a plurality of segmental sheet metal sections integrally united to form a substantially circular unit having its margin overlapping said flange, and a continuous circumferential weld integrally uniting said outwardly directed flange with said margin of said top wall to integrally unite said top and side walls.

14. In a tank, the combination with a curved vertical side wall having an outwardly directed flange along the top margin thereof, of a top wall comprising a plurality of segmental sheet metal sections lapped along the radial edges thereof and integrally united by welding to form a substantially circular unit having its margin overlapping said flange and having integral bracing means on the under side thereof, and a continuous circumferential weld integrally uniting said outwardly directed flange with said margin of said top wall to integrally unite said top and side walls.

ANDREW A. KRAMER.