AST Aboveground Storage Tank Forum RSS Welcome the aboveground storage tank forum, a bulletin board dedicated to tanks, fuel tanks, plastic tanks, fuel storage tanks, and above ground storage tanks for engineers, tank operators, maintenance personnel, and technicians who work on or around these aboveground storage tanks (AST) and chemical plastic tanks. 6/25/2017 8:09:42 PM Earl at AST Aboveground Storage Tank Forum RSS 180 150 rescue plan from efrt - By: rl [521] Hi all<br />What is rescue plan for an unconscious worker from EFRT ?<br />Threw the rolling lader? Other?<br />Thanks Sat, 24 Jun 2017 13:18:00 -0300 Re: IFR Tank - By: Dunedin [37] I assume the actuated pressure relief is on the tank itself so not really relevant to type if IFR. The burp type of relieve valve is unlikely to be effective with crude and my advice is go for a simple permanent open type of valve that will not get clogged up with the crude - install a few of them, just in case!!. Fri, 23 Jun 2017 05:01:00 -0300 Re: IFR Tank - By: Kumaran [1861] Can we use pontoon type aluminium floating roof with actuated pressure relief and open type burp valve. Fri, 23 Jun 2017 02:43:00 -0300 Re: IFR Tank - By: Dunedin [37] I agree entirely with David, an IFR in a crude storage tank is possible. Avoid the pontoon and closed cell types and go for a design based on the open raft concept. Mechanical seals are necessary as other types will be useless in contact with the crude. Use permanently open pressure relief valves as the flapper type will struggle with the crude. Thu, 22 Jun 2017 00:58:00 -0300 Re: Dynamic Liquid Hoop Forces - By: [39] This is covered in API 650 Annex E.6.1.4 but seldom are the controlling condition. Wed, 21 Jun 2017 21:31:00 -0300 Re: IFR Tank - By: [39] Aluminum covers are in lots of crude oil tanks. 70 DegC is not all that hot but you need to verify the weld wire suitability and especially the compatibility of non-metallic parts. A double mechanical shoe seal may be your best option. Also enclosed spaces like pontoons and sealed panels may have pressure/vacuum issues over time - best to use a design that does not have enclosed flotation compartments. Also the true vapor pressure at the storage temperature cant exceed the EPA limit of 76.6kPa. There is probably more but you have a start... Wed, 21 Jun 2017 15:05:00 -0300 IFR Tank - By: Kumaran [1861] Can we use aluminum internal floating roof for crude oil storage tank. The tank is design for 70 deg centigrade with steam heating coil. Kindly help us.<br /> Wed, 21 Jun 2017 06:14:00 -0300 How to inspect the holder under botton plates ? - By: Orlando Costa [201] Usually, the cryogenic tank with double wall has an outlet to the product under the bottom plates in the periphery of them. In this area, there is a holder to avoid any movements of this outlet pipe. Has anyone in this forum ever detected any damage of this component the holder? For example, corrosion? How can I identify it? Will it be necessary to cut off the bottom plates to inspect this item? Sun, 18 Jun 2017 15:21:00 -0300 Re: Radial welds cross tank shell - By: [39] NDE the annular plate butt weld prior to sliding them into final location. Wed, 7 Jun 2017 17:13:00 -0300 Re: Radial welds cross tank shell - By: Tankee [235] I do not see where 653 requires a full penetration corner weld anywhere over an annular ring our its butt welds. I f you want to, you can write it into your procedures the bevel a certain amount across the top and on each side of a butt weld, but I see it as unnecessary. Mon, 5 Jun 2017 17:48:00 -0300 Re: Self-Supported vs Supported cone roof - By: ITS [1678] Well, that is a large diameter tank that is non-self supporting. <br /><br />In essence, since there is no columns or center column supporting the tanks roof then is it is a self supporting conical roof. It is that simple. <br /><br />We can all guess that your 70 foot diameter tank is older when API 12C was in place and good engineering. <br /><br />Obviously the test of time has proven your tank self supporting conical roof to be a worthy or robust design. In those older days the self supporting conical roofs were generally did not exceed 60 feet, and when they do the compression ring is going to be very robust. Usually the self supporting conical roofs were 35 feet to 45 feet. Sat, 3 Jun 2017 12:10:00 -0300 Re: Self-Supported vs Supported cone roof - By: MPS [622] Can anyone please revert? Fri, 2 Jun 2017 01:10:00 -0300 Re: Radial welds cross tank shell - By: ADI HAR-SHOSHAN [93] 1. Because you inserting a new annular plate in to a slotted shell and the shell THK let say is 32.0mm thick ,how do you make sure that the portion of the new Radial butt weld that cross under the shell between the two annulars is fully bonded without discontinuties to the rest of the this radial butt weld?<br /><br />2.Does this cross weld should be prepare for full penetraion weld with the shell ? <br /><br /><br /> Fri, 2 Jun 2017 00:37:00 -0300 Re: Radial welds cross tank shell - By: Tankee [235] Are you asking how to inspect the butt weld directly under the shell, how to test it, minimum distances of shell welds, or what? Im not exactly clear on what you are asking. Thu, 1 Jun 2017 17:17:00 -0300 Radial welds cross tank shell - By: ADI HAR-SHOSHAN [93] When inserting new annular plates in an slotted tank shell ,how does API-653 relate to the new Radial butt welds that cross the under the shell between the annulars with regards to the inspection of this portion? Tue, 30 May 2017 06:49:00 -0300 Re: Double deck and Single deck pontoon - By: MPS [622] Any updates? Mon, 29 May 2017 22:21:00 -0300 Re: Self-Supported vs Supported cone roof - By: MPS [622] Thanks David.<br /><br />Is there any way to check the design is good or not? <br /><br />Roof span can be checked per API650 for external loading and Roof THK can be checked per API650 F.6.1. for internal pressure. <br /><br />Calculated Roof THK per API650 is very high, more than allowable limit of 0.5. Mon, 29 May 2017 22:18:00 -0300 Re: Self-Supported vs Supported cone roof - By: [39] This type of tank roof does not meet either definition in API 650. It falls into Alternate Designs Mon, 29 May 2017 07:38:00 -0300 Self-Supported vs Supported cone roof - By: MPS [622] Dears,<br /><br />Can someone make me clear the difference between self-supported cone roof vs supported cone roof? <br /><br />We have a 70 ft diameter tank with cone roof slope of 2:12, cone roof plate THK 5/16&#226;&#8364;&#157; and 36 numbers rafters L-Angle L7x4x0.5 located externally welded to roof plate. <br /><br />Can we consider this geometry as self-supported cone roof tank per API650 5.10.5 OR this will be treated as supported cone roof tank per API650 5.10.4? Mon, 29 May 2017 02:13:00 -0300 Re: Aluminium Internal Floating Roof - By: Dunedin [37] Compatabilty of fire suppression products with the aluminum alloys used in manufacture of the IFR is not so important as the only time they will be in contact with each other is when there is a fire. Concerning the weight of the fire suppression products on top of the IFR this will not be an issue as all IFR,s have excess buoyancy built into their design. Sun, 28 May 2017 00:44:00 -0300