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Dike Wall Calculation
- gkumar
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14 years 2 weeks ago - 14 years 2 weeks ago #7824 by gkumar
Dike Wall Calculation was created by gkumar
Hello All,
Can anyone brief me about the Dike Wall Calculation..? How do we calculate the dike for two tanks of different diameter. What are the different criteria which we consider (like foundation, volume...?)
Please elaborate with an example. (I don't have any data at this time).
Thanks,
GKumar
Can anyone brief me about the Dike Wall Calculation..? How do we calculate the dike for two tanks of different diameter. What are the different criteria which we consider (like foundation, volume...?)
Please elaborate with an example. (I don't have any data at this time).
Thanks,
GKumar
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- shrivallabha
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14 years 2 weeks ago - 14 years 2 weeks ago #5206 by shrivallabha
Replied by shrivallabha on topic Re: Dike Wall Calculation
In non-walled situation, if the tank wall breaks then the chemical / fluid inside will spread in uncontrolled manner (so will be the hazards associated).
The Dike which is also called Bund wall is built to prevent this uncontrolled spreading. In short, Dike is retention measure. In case of single tank, it should be more than the tank's capacity. Normally it is:
Dike Capacity = 1.1 * Vessel Capacity
Please note:
1. The calculation shall be based on the inside dimensions of the Dike and not outside.
2. Any Civil constructions that are inside the Dike like foundations shall be correctly calculated and accounted for. Otherwise the calculation will result in incorrect dimensions and reduced retention capacity.
Economy and Engineering sense, mean that Tanks with similar purpose are placed together with a common Dike. In this case, the volume of the largest vessel is considered for calculation. This reduces
1. Civil work
2. Dike wall height (as the area is increased)
So it becomes more cost effective.
However, as a piper, our responsibility does not end here. Following points shall be considered as well
1. Openings for pipe entry in the Dike (Puddle flange requirement)
2. Entry / Exit for the operators with due consideration for wind direction and fire hazard.
The Dike which is also called Bund wall is built to prevent this uncontrolled spreading. In short, Dike is retention measure. In case of single tank, it should be more than the tank's capacity. Normally it is:
Dike Capacity = 1.1 * Vessel Capacity
Please note:
1. The calculation shall be based on the inside dimensions of the Dike and not outside.
2. Any Civil constructions that are inside the Dike like foundations shall be correctly calculated and accounted for. Otherwise the calculation will result in incorrect dimensions and reduced retention capacity.
Economy and Engineering sense, mean that Tanks with similar purpose are placed together with a common Dike. In this case, the volume of the largest vessel is considered for calculation. This reduces
1. Civil work
2. Dike wall height (as the area is increased)
So it becomes more cost effective.
However, as a piper, our responsibility does not end here. Following points shall be considered as well
1. Openings for pipe entry in the Dike (Puddle flange requirement)
2. Entry / Exit for the operators with due consideration for wind direction and fire hazard.
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- sidjain
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14 years 1 week ago - 14 years 1 week ago #5534 by sidjain
Replied by sidjain on topic Re: Dike Wall Calculation
Hi Gkumar
pl. go to following link.
www.pstif.org/apps/dike_calculation_sheet_e.pdf
Hope this helps
Siddharth Jain
pl. go to following link.
www.pstif.org/apps/dike_calculation_sheet_e.pdf
Hope this helps
Siddharth Jain
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- AbhijitN
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13 years 4 months ago - 13 years 4 months ago #5984 by AbhijitN
Replied by AbhijitN on topic Re: Dike Wall Calculation
Dear All,
Do you have anything on the subject Dike wall calculation? I understand that volume of the dike should 110% of the tank volume if it is a single tank & if there are multiple tanks of the same purpose/fluid, we should consider the dike volume as 110% of the largest tank in the group.
I still have many queries to solve to become confident enough to do it myself on live projects.......
-I have already gone through number of posts on this forum but i think there is a need for an example to understand it in a better fashion?
-Are there any limitations to Length, Breadth, Height except from available space point of view?
-How we should treat the tank foundation in the dike?
-Access point of view considerations?
-Pipe connections through dike? How we make sure the spillage does not go out of the dike in any case?
-There are ready made xls sheets (with intelligent formulas) where we just put the volume of the tank & you get the results of the dike dimensions but we understand first what kind of calculations we are doing exactly ??
Thanks in advance,
Abhijit
Do you have anything on the subject Dike wall calculation? I understand that volume of the dike should 110% of the tank volume if it is a single tank & if there are multiple tanks of the same purpose/fluid, we should consider the dike volume as 110% of the largest tank in the group.
I still have many queries to solve to become confident enough to do it myself on live projects.......
-I have already gone through number of posts on this forum but i think there is a need for an example to understand it in a better fashion?
-Are there any limitations to Length, Breadth, Height except from available space point of view?
-How we should treat the tank foundation in the dike?
-Access point of view considerations?
-Pipe connections through dike? How we make sure the spillage does not go out of the dike in any case?
-There are ready made xls sheets (with intelligent formulas) where we just put the volume of the tank & you get the results of the dike dimensions but we understand first what kind of calculations we are doing exactly ??
Thanks in advance,
Abhijit
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- Jop
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13 years 4 months ago - 13 years 4 months ago #5928 by Jop
Do it once and Do it Right
Replied by Jop on topic Re: Dike Wall Calculation
cj.abhijit ,
"Are there any already made xls sheets (with intelligent formulas) where we just put the volume of the tank & you get the results of the dike dimensions but we understand first what kind of calculations we are doing exactly?"
Answer: I made a spread sheet just as you describe about 15 years ago. In my travels since then I have lost it. I will work on making a new one and get back to you.
Considering your other questions:
-Are there any limitations to Length, Breadth, Height except from available space point of view?
Answer: No, not formally. There is common sense which says don't put tanks storing the different product in the same dike area. Don't make the dike area so big that you cannot get access to a tank in a safe manner.
-How should we treat the tank foundation in the dike?
Answer: Calculate the displaced volume and add it to the containment volume requirement.
-Access point of view considerations?
Answer: There are two kinds of access. There is walking access for operators and there is vehicle access for maintenance. The operator access should be from a point nearest the pumps so the operator can get from the pumps to (and from) the tank (s) in the most direct line. There should also be an alternate egress (escape) route in case of fire or other hazard.
Maintenance access should be up and over the dike from a road that is preferably not on the same side as a sleeper pipe rack. On the same side is normally just too complicated
-Pipe connections through dike? How we make sure the spillage does not go out of the dike in any case?
Answer: I used and recommend a "Sleeve" type of dike penetration. I will need some time to work up a sketch to convey the details if you do not understand the following.
Basically it is:
a- a product pipe inside a larger sleeve pipe. example: 8" (DN200) inside a 14" (DN350). Adjust the sleeve size based on the required product line size by adding 6" (150mm) and round off to the closest line size.
b- the sleeve pipe is anchored in the center of the dike with a "Puddle Flange" embedded in a concrete block to form an anchor. The sleeve pipe is long enough to go through the dike at the proper elevation plus one (1) meter on each side of the dike.
c- the end of the sleeve pipe that faces the inside of the dike area is open for drainage in case of leakage.
d- the end of the sleeve pipe that faces the outside of the dike area is fitted with a "sleeve" size Slip-On (or weld Neck) flange. Slip-On is normally cheaper and there is no pressure or temperature considerations to be worried about.
e- the product pipe is fitted with "Spider Guides." These are metal spacers welded to the product pipe (3 meter spacing) that keep the product pipe centered inside the sleeve.
f- the product pipe is fitted with a sleeve size to product line size slip-on reducing flange (this flange bolts to the Sleeve flange in "d" above)
g- the product pipe continues on both sides of the dike in a normal manner consistent with your overall design.
h- Multiple dike penetrations in the same area would be done the same manner, you would just need to increase the line spacing to the sleeve size not the product line size.
I hope this helps.
"Are there any already made xls sheets (with intelligent formulas) where we just put the volume of the tank & you get the results of the dike dimensions but we understand first what kind of calculations we are doing exactly?"
Answer: I made a spread sheet just as you describe about 15 years ago. In my travels since then I have lost it. I will work on making a new one and get back to you.
Considering your other questions:
-Are there any limitations to Length, Breadth, Height except from available space point of view?
Answer: No, not formally. There is common sense which says don't put tanks storing the different product in the same dike area. Don't make the dike area so big that you cannot get access to a tank in a safe manner.
-How should we treat the tank foundation in the dike?
Answer: Calculate the displaced volume and add it to the containment volume requirement.
-Access point of view considerations?
Answer: There are two kinds of access. There is walking access for operators and there is vehicle access for maintenance. The operator access should be from a point nearest the pumps so the operator can get from the pumps to (and from) the tank (s) in the most direct line. There should also be an alternate egress (escape) route in case of fire or other hazard.
Maintenance access should be up and over the dike from a road that is preferably not on the same side as a sleeper pipe rack. On the same side is normally just too complicated
-Pipe connections through dike? How we make sure the spillage does not go out of the dike in any case?
Answer: I used and recommend a "Sleeve" type of dike penetration. I will need some time to work up a sketch to convey the details if you do not understand the following.
Basically it is:
a- a product pipe inside a larger sleeve pipe. example: 8" (DN200) inside a 14" (DN350). Adjust the sleeve size based on the required product line size by adding 6" (150mm) and round off to the closest line size.
b- the sleeve pipe is anchored in the center of the dike with a "Puddle Flange" embedded in a concrete block to form an anchor. The sleeve pipe is long enough to go through the dike at the proper elevation plus one (1) meter on each side of the dike.
c- the end of the sleeve pipe that faces the inside of the dike area is open for drainage in case of leakage.
d- the end of the sleeve pipe that faces the outside of the dike area is fitted with a "sleeve" size Slip-On (or weld Neck) flange. Slip-On is normally cheaper and there is no pressure or temperature considerations to be worried about.
e- the product pipe is fitted with "Spider Guides." These are metal spacers welded to the product pipe (3 meter spacing) that keep the product pipe centered inside the sleeve.
f- the product pipe is fitted with a sleeve size to product line size slip-on reducing flange (this flange bolts to the Sleeve flange in "d" above)
g- the product pipe continues on both sides of the dike in a normal manner consistent with your overall design.
h- Multiple dike penetrations in the same area would be done the same manner, you would just need to increase the line spacing to the sleeve size not the product line size.
I hope this helps.
Do it once and Do it Right
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- AbhijitN
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13 years 4 months ago - 13 years 4 months ago #5673 by AbhijitN
Replied by AbhijitN on topic Re: Dike Wall Calculation
I must thank you for efforts you are taking to make us understand things & the huge amount of quality knowledge you have with piping related things/activities.
Your reply is helping me a lot but a roughly drawn sketch will be a great help..!
Thank you a lot,
Abhijit
Your reply is helping me a lot but a roughly drawn sketch will be a great help..!
Thank you a lot,
Abhijit
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