US1976592A - Drain for breather type roofs - Google Patents

Description

Oct. 9, 1934. .J, H. WIGGINS DRAIN FOR BREATHER TYPE ROOFS Filed June 27. 1932 FIGI.

FIGZ.

INVENTOR Jo /V/1.Wl 6/ 5 W Patented Oct. 9, 1934 DRAIN FOR BREATHER TYPE ROOFS John H. Wiggins, Tulsa, Okla.

Application June 27, 1932, Serial No. 619,378

2 Claims.

This invention relates to a drain for conducting rain or snow water from the top side of tank roofs of the type commonly referred to as breather roofs, which, as is well known, usually consist 5 of a metallic diaphragm constructed in such a manner that in the normal use of the tank the central portion of the diaphragm flexes upwardly and downwardly, due to variations in the internal pressure of the tank.

One object of my invention is to provide a relatively compact metallic drain for a breather type roof that will not interfere with the flexing of the roof, and in turn, will not be injuriously affected by the flexing of the roof.

Another object is to provide an eflicient drain for breather type roofs, that is easy to install and of such construction or design that no parts of same will contact with or strike against the stationary supporting structure on the inside of the tank, used to sustain the roof in its downwardly deflected condition.

Another object is to provide a drain for breather type roots, which is of such construction or design that no portion of same is located very far below the top of the tank, with the result that in case of any leakage, there is not a high liquid head that will cause rapid leakage.

And still another object is to provide a storage tank having a breather roof and a drain for said roof that can be removed without taking the tank out of service and without the necessity of drawing off liquid from the tank to lower the level of the liquid.

To this end I have devised a drain which, briefly described, consists of a metallic conduit arranged in close proximity to the top of the tank and extending inwardly from the tank side wall, preferably for only a portion of the radius of the roof, and means for attaching or combining said conduit with the roof and with the tank side wall in such a way that said conduit is capable of moving bodily sufficiently, when the roof flexes upwardly or downwardly, to not interfere with the flexing or movement of the roof, and in turn, not be injuriously affected by the movement of the roof. Said conduit is preferably located in the space between the underside of the roof and the normal high level of the liquid in the tank, and it is so arranged that it will not contact with or strike against the roof beams or other supporting structure inside of the tank on which the roof rests whenthe roof is inits downwardly flexed condition. The method or particular means used to combine said conduit with the roof and side wall is immaterial, and may be varied in numerous ways Without departing from the spirit of my invention, but I prefer to pivotally connect the inner end of said conduit to a sump on the roof located at a point remote from the center of the roof and attach the opposite end of said conduit to a jointed tubular structure sustained or carried by the tank side wall and constructed in such a manner that it forms a continuation of said condiut which is capable of moving in such a way as to permit said conduit to move bodily in a radial direction when the central portion of the roof flexes upwardly and downwardly, whereby the drain will not interfere with the flexing of the roof and the drain, in turn, will not be injuriously affected by the flexing of the roof.

Figure 1 of the drawing is a fragmentary vertical transverse sectional view of a breather type roof equipped with a drain constructed in accordance with my invention.

Figure 2 is an enlarged fragmentary vertical transverse sectional view of the roof and the drain.

Figure 3 is a top plan view of the drain with the rcof broken away so as to show the arrangement of the drain with relation to the roof support.

Figure 4 is a vertical sectional view, taken on the line 4-4 of Figure 3, looking in the direction indicated by the arrows.

Figure 5 is a vertical sectional view, taken on the line 5-5 of Figure 3, looking in the direction indicated by the arrows; and

Figure 6 is a top plan view of the sump on the roof to which the inner end of the drain is attached.

In the accompanying drawing, which illustrates the preferred form of my invention, A designates the side wall of a liquid storage tank, and B designates a breather type roof for said tank formed usually from a flexible metallic diaphragm whose peripheral portion is attached to the tank side wall and whose central portion is capable of flexing upwardly and downwardly to vary the volume of the internal space of the tank located above the level of the liquid in the tank. When the roof B is in its downwardly flexed condition, the roof rests upon a stationary supporting structure which is usually composed of a number of radially-disposed roof beams 1 that project inwardly from the side wall of the tank and whose inner ends rest upon or are connected to an annular framing 2, which, in turn, is supported by posts or uprights 3, as shown in Figures 1 and 2. The conventional breather roof, in its downwardly flexed condition, comprises a flat central portion that constitutes from one-half to two-thirds of the radius of the roof, and in the normal use of the tank, the variation in the internal pressure of the tank causes the central portion of the roof to rise and fall or to flex upwardly and downwardly.

My invention consists of a drain for a tank roof of the general type referred to, that is located on the underside of the roof in the space between the roof and the normal high level of the liquid in the tank, and which has provision for permitting the drain as an entirety to move sumciently to adapt itself to the flexing of the roof, or in other words, to not interfere with the flexing of the roof, or in turn, be injuriously affected by the flexing of the roof. Said drain extends inwardly only a portion of the radius of the roof, and it is arranged beyond or outside of the annular framing 2 of the roof supporting structure, preferably between two of the radiallydisposed roof beams 1. It is made up of metallic parts, and in the preferred form of my invention herein illustrated comprises a conduit or pipe 4, in hydraulic gradient, that leads from a sump 5 on the roof to a jointed tubular structure carried by the side wall A of the tank and constructed so as to form an outlet for the conduit 4 through which water escapes from the sump 5 and is discharged at a point outside of the tank. The sump 5 is herein illustrated as consisting of a cast iron box connected by fastening devices 6 to a plate 7 that is welded to the roof B, and the pipe or conduit 4 previously referred to has its inner end pivotally connected to the sump 5 by means of a conventional street L 8, one of whose legs or portions is disposed horizontally and screwed into an internally-threaded hole formed in one of the vertical side walls of the metal box that constitutes the sump 5.

The jointed tubular structure, previously referred to, is connected to the opposite end of the conduit 4, and in the form of my invention herein illustrated comprises a horizontally-disposed stationary pipe 9 mounted on and projecting inwardly from the tank side wall A, a horizontally-disposed movable pipe 10 arranged between the stationary pipe 9 and the outer end of the conduit 4, and pivotal joints or connections between said parts 9, 10 and 4 constructed in such a way as to permit the conduit 4 to move bodily radially with respect to the tank side wall when the roof B flexes upwardly and downwardly. One of the pivotal connections or joints just referred to is formed preferably by a street L 11 on the conduit 4 that is screwed into an L 12 carried by the movable pipe 10, and the other pivotal con-,

nection or joint is preferably formed by a street L 13 on the opposite end of the pipe 10 that is screwed into an L 14 carried by the stationary pipe 9. Usually, the pipe 10 will be composed of two sections joined together by a pipe union or equivalent means 15 that will facilitate the assembly or disassembly of the parts constituting the drain. A bracket 16 that projects inwardly from the tank side wall serves as a support for the horizontally movable pipe 10, and the tank side wall is provided with a removable hand hole plate 17' held in position by fastening devices 17a, that provides access to the drain. In order that the pivotal connection between the inner end of the conduit 4 and the sump 5 may be kept thoroughly lubricated, the part on the side wall of the sump into which the street L 8 is screwed, is provided with a lubricant duct 18 (see Figure 5) that is adapted to be filled with grease or some other suitable lubricating medium, said duct being normally closed by a removable plug 19.

In a drain of the construction above described the conduit 4 will assume different angular positions with relation to the roof and will move radially with respect to the side wall of the tank when the roof flexes upwardly and downwardly, due to the fact that the inner end of the conduit 4 is pivotally connected to the sump 5 and the outer end of said conduit is attached to a jointed structure on the side wall that comprises two angularly-disposed joints or pivots, which form in effect a universal connection between the conduit 4 and the stationary pipe 9 on the tank side wall that constitutes the discharge portion of the drain. Accordingly, such a drain will not interfere with the flexing of the roof, and in turn, the drain will not be injuriously affected or subjected to strains tending to cause it to leak, by the movement or flexing of the roof. As the drain is'located outside of or beyond the annular-framing 2 of the roof supporting means, between two of the roof rafters, 1, it will not contact with or strike against the roof supporting means when the roof flexes upwardly anddownwardly. The drain is short and compact and extends inwardly from the tank side wall only a portion of the radius of the roof, and as no portion of same is located very far below the top of the tank, there is not a high liquid head that will cause rapid leakage, in the event a slight leak develops in the drain. In such a drain the leakage would normally be only vapor, which would do very little harm. Moreover, as the drain is in hydraulic gradient, water cannot collect and freeze in same and cause the drain to rupture. In addition to the desirable characteristics above pointed out, my drain has the added advantage of being capable of being removed from the tank for cleaning, inspection or repair, without taking the tank out of service and without the necessity of drawing 01f liquid from the tank so as to lower the level of the liquid. This, of course, results from the fact that the drain is located above the normal high level of the liquid in the tank, and is detachably connected to the roof and to the tank side wall in such way that after the drain has been disconnected from said parts, the drain can be bodily removed from the tank through the opening in the tank side wall that is normally closed by the removable hand hole closure 17. To remove the drain the sump 5 is detached from the roof and the closure 17 is detached from the tank side wall. A rope is then tied to some part of the drain, and the entire drain is then pulled outwardly through the hand hole opening in the tank side wall that is normally closed by the plate 17.

Having thus described my invention, what I claim and desire to secure by Letters Patentis: 1. A storage tank provided with a side wall, a breather type roof for said tank, a, sump on said roof located at a point between the side wall and the center of the roof, a metal drain pipe on the underside of the roof pivotally attached at its inner end to said sump and extending substantially radially from same towards said side wall, and a jointed metallic structure carried by said side wall and combined with said drain pipe so as to form a continuation of same, said jointed structure having provision for permitting the drain pipe to move substantially radially with respect to said side wall when the roof flexes.

2. A tank of the kind described in claim 1, in which the tank side wall is provided adjacent its upper edge with an opening through which said drain pipe and jointed structure can be withdrawn from the interior of the tank, and a closure for said opening.

JOHN H. WIGGINS.

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