US2315023A - Water drain for floating roof tanks - Google Patents

Description

March 30, 1943. H. M. STEVENSON WATER DRAIN FOR FLOATING- ROOF TANKS Filed June 10, 1939 \\\\\\\\\\\N NN\\\\\\\\\N\NN\\\ \\\N\NN\\\\\\\\\\ WN\\\\ \\\\\\\\N\\\ NN MN lI/I/I/IIl/l/II/ IIIIIIII III/ [$11 11/ Ill/j Patented Mar. 30, 1943 WATER DRAIN FOR FLOATING ROOF TANKS Hugh M. Stevenson, Houston, Tex., assignorto Standard Oil Development Company, a corporation of Delaware Application June 10, 1939, Serial No. 278,442

1 Claim.

The present invention is directed to an improvement in floating roof tanks and has a particular reference to means for preventing the accumulation of water on the roofs of such tanks.

Various types of roof tanks are known in the art. In general, the floating roof has a sliding fit with the inner walls of the tank which is achieved by a ring of packing material around the circumference of the roof. Necessarily, this fit cannot be too tight, because it must permit free movement of the roof. For this reason, the prevention ofleakage of water into the tank has always presented a problem.

It has been the practise to provide a sump on the floating roof for the collection of water and a conduit from this sump to a point outside the tank for the drainage of the collected water. Because the roof is movable the drainage pipe must necessarily be one which can be moved with the roof. It has been the practice, therefore, to use a metal drainage pipe composed of joints swingingly connected to each other and arranged inside the tank having one Of its ends connected to the sump and the other connected to an outlet at the bottom of the tank. The joints in this drainage pipe have always been a source of trouble since they are inclined to leak and as soon as a leak develops it is necessary for workmen to enter the tank and repair it. Because of safety requirements, workmen cannot enter a tank until it has been wholly freed of toxic vapors and gases. The cleaning of a tank in this. manner involves anexpenditure of several hundred dollars and when this procedure has to be repeated several times a year, its cost becomes prohibitive.

The principal object of the present invention is the provision of a drainage pipe for a floating roof which will eliminate the difliculties attending drainage pipes of known types and which will also make possible a new method of replacement in which workmen need not enter the tank.

Specifically, the present invention resides in the provision of a flexible drainage pipe resistant to oil which is so connected to the sump at one end and to the bottom of the tank at the other that it can be removed and replaced from the outside.

The present invention will be better understood from the following detailed description of the acompanying drawing in which the single figure is a vertical section through a floating roof tank, only part of which is shown, showing the drainage pipe of 'the present invention in place.

Referring to the drawing in detail, numeral l designates the vertical wall of a tank having a floating roof 2 which is provided with a circumferential seal 3 of conventional type which will permit the roof to slide along the surface of wall I. The roof is provided at its center with a sump 4 having a covering 5 and with a hatch 6 spaced a short distance from the sump and provided with a cover I.

Arranged in the wall of the sump is a packing 8 through which passes a pipe 9 which extends from the sump to a point underneath the hatch where it is held in place by a bracket Ill. The end of the pipe under the hatch terminates in a flange II to which is bolted a flange i2 carrying a nipple l3 which frictionally holds one end of a rubber-like hose M. This hose is preferably made of a synthetic rubber which is resistant to oil such as of polymerized butadiene, chlorprene, or the like. The hose is made...in -a--conventional manner with fiber reinforcement and in laminated form. It is sufficient if the outside layer of the hose is made of oil resistant material. For safety it is preferred to make both the outside and inside layers of the hose of the aforesaid synthetic rubber. In order to relieve the load on the friction between the hose and the nipple the hose is provided a short distance from this connection with a clamp l5 which is connected to a chain l6 anchored in the hatch opening.

Near its lower end, the tank is provided with an opening in which is Welded a pipe I! greater in diameter than the hose I4, The outer end of this pipe is providedwith a flange i8 to which is bolted another flange [9 through which is screwed a pipe 20 to the inner end of which the hose i4 is frictionally connected and bound with clamps 2 i. The outer end of the pipe 20 is pro vided with a gate valve 22, so that if the hose should spring a leak, loss of oil can be prevented.

When it is necessary to repair the hose M, a line is connected to its upper end through the hatch I and its upper end is then disconnected from nipple l3 and chain it. Either then, or before, the oil is drained out of the tank to a point below the level of pipe l'i. Flange I9 is then removed and the hose is drawn out through pipe I! carrying the aforesaid line with it. The end of the line after it is pulled out of pipe [1 is connected to the upper end of the replacement hose which is then pulled up into place through hatch I and connected to nipple I3 and chain IS. The lower end of the replacement hose is connected to pipe 20 in the manner shown and flange I 9 is bolted back in place.

It will be apparent that changes can be made intthe specific construction shown without departing from'the scope of applicant's invention. While applicant has mentioned specific synthetic rubbers which may be employed, theremay be other flexible materials having oil resistivity which'canalso be utilized and some such materials may, be later developed, which will be applicable. It may be mentioned also that applicants invention ofiers considerable advantages over present practices even when a rubber hose is employed, because the cost of such hose and its replacement, even though such replacement is frequently necessary, islless, than the expense incurred with the use of the drainage pipe hitherto employed. v M 1 v The nature and'objects of -the present invention havingbeen thus described and illustrated,

what is claimed as new andvuseful and is desired to be secured by Letters Patent is:

In a floating roof tank'a sump for collection of water on said roof, a hatch in said roof adjavcent said sump, an outlet nipple on said sump having its end projecting into the interior of said tank at a point beneath said hatch and adjacent thereto, a short pipe arranged in the wall of the tank adjacent the bottom end to project into' the interior of the tank and provided with a flange at its outer end, a mating flange detach- HUGH M. s'rEv NsoN.

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