Sir, your videos are short, yet very informative, thanks, your comment section is interesting as well. I know about the factors affecting the CA, but it would be of great help if you provide us with another video focusing on CA. thanks again
Thank you for your interest. The corrosion allowance is determined based on some factors, principally the construction material and the stored fluid properties, but also the operating conditions, the expected service life of the storage tank, the safety factors and the applicable standards, etc. Typical corrosion allowances can range from 1.5 mm to 6 mm for carbon steel storage tanks and sometimes as low as 1 mm or less for more resistant material to corrosion such as stainless steel. It is to not that corrosion allowance shoud be optimized under some economic consideratons and it should be, also, agreed by the customer. Please feel free to ask.
THANKS MR. RACHED . I HAVE A Q UESTION WHICH IS , HOW TO KNOW THE HEIGHT AFTER THE LAST COURSE OF THE STEEL STORAGE TANK(AFTER TOP OF SHELL HEIGHT TO THE BEGINING OF ROOF)?
Thank you for your interest. First of all, it is to note clearly that the shell courses extend from the bottom of the tank to the top, where they meet the roof or cover of the tank. Thus, the height distance between the top of the "last" shell course and the beginnig of the roof is theoretically zero. But, please note that in the "last" shell course, the level of the stored fluid may not cover the whole height of the "last" shell course. The level of the stored fluid can be, for example, just one half or one third the height of the "last" shell course. It depends on the design liquid level of the stored fluid (imposed by an overfill slot governing the maximum capacity of the storage tank) with regard to the height of the storage tank between the bottom and the top of shell height where the roof begin. For further assimilating my answer, please see Figure 5-4-Storage Tank Volumes and Levels in API650.
Thank you for your interest. the direct answer to your question is: The one-foot method is elaborated ("designed") to calculate the required thicknesses at specified design points located at 0.3 m (1 ft) height above the bottom of each shell course. You can check this information in API 650-5.6.3.1. Also, you can see a detailed explanation about the reason behind why 0.3 m in the reference : doi.org/10.1016/j.engstruct.2015.07.050 which explains that: "...The required shell plate thickness for each shell course is calculated using the circumferential stress at a point 0.3 m (1-ft) above the lower horizontal weld seam of the shell course due to hydrostatic pressure of the stored liquid. The reasoning behind this assumption is that the tank bottom plates provide restraint to reduce circumferential stress due to hydrostatic pressure at the bottom 0.3 m (1-ft) of the lowest shell course...". This is "in contrast" with the Variable-design-point method which permits to calculate shell thicknesses at design points that result in the calculated stresses being relatively close to the actual circumferential shell stresses. This will provide a reduction in shell-course thicknesses and total material weight( see API 650 5.6.4.1 and 5.6.4). If you have any other questions, please do not hesitate to ask.
Sir, your videos are short, yet very informative, thanks, your comment section is interesting as well. I know about the factors affecting the CA, but it would be of great help if you provide us with another video focusing on CA. thanks again
Ok sir, as soon as possible. Thank you very much indeed for your interest.
You are sir, i am not sir :D I am just a humble junior tank engineer from Egypt and I send you and all Tunisia my warm regards < 3 @@HITS2009
جزاك الله خيرا 🌺
is the courses height is equal ? how can i know the course dimensions
thank this was very clear and I I appreciate to aske could you explain how determine the CA
Thank you for your interest. The corrosion allowance is determined based on some factors, principally the construction material and the stored fluid properties, but also the operating conditions, the expected service life of the storage tank, the safety factors and the applicable standards, etc. Typical corrosion allowances can range from 1.5 mm to 6 mm for carbon steel storage tanks and sometimes as low as 1 mm or less for more resistant material to corrosion such as stainless steel. It is to not that corrosion allowance shoud be optimized under some economic consideratons and it should be, also, agreed by the customer. Please feel free to ask.
THANKS MR. RACHED .
I HAVE A Q UESTION WHICH IS , HOW TO KNOW THE HEIGHT AFTER THE LAST COURSE OF THE STEEL STORAGE TANK(AFTER TOP OF SHELL HEIGHT TO THE BEGINING OF ROOF)?
Thank you for your interest. First of all, it is to note clearly that the shell courses extend from the bottom of the tank to the top, where they meet the roof or cover of the tank. Thus, the height distance between the top of the "last" shell course and the beginnig of the roof is theoretically zero. But, please note that in the "last" shell course, the level of the stored fluid may not cover the whole height of the "last" shell course. The level of the stored fluid can be, for example, just one half or one third the height of the "last" shell course. It depends on the design liquid level of the stored fluid (imposed by an overfill slot governing the maximum capacity of the storage tank) with regard to the height of the storage tank between the bottom and the top of shell height where the roof begin. For further assimilating my answer, please see Figure 5-4-Storage Tank Volumes and Levels in API650.
Thanks Mr. Rashed , I appreciate your helping.
@@MUAADHMOHAMMEDMOHSENAL-QUSARI I am at your service. Do not hesitate to ask.
Why 0.3 m. I know that it is called one foot method but can you give me the reference that tells me why 0,3m.
Thank you for your interest. the direct answer to your question is:
The one-foot method is elaborated ("designed") to calculate the required thicknesses at specified design points located at 0.3 m (1 ft) height above the bottom of each shell course. You can check this information in API 650-5.6.3.1.
Also, you can see a detailed explanation about the reason behind why 0.3 m in the reference :
doi.org/10.1016/j.engstruct.2015.07.050
which explains that:
"...The required shell plate thickness for each shell course is calculated using the circumferential stress at a point 0.3 m (1-ft) above the lower horizontal weld seam of the shell course due to hydrostatic pressure of the stored liquid. The reasoning behind this assumption is that the tank bottom plates provide restraint to reduce circumferential stress due to hydrostatic pressure at the bottom 0.3 m (1-ft) of the lowest shell course...".
This is "in contrast" with the Variable-design-point method which permits to calculate shell thicknesses at design points that result in the calculated stresses being relatively close to the actual circumferential shell stresses. This will provide a reduction in shell-course thicknesses and total material weight( see API 650 5.6.4.1 and 5.6.4).
If you have any other questions, please do not hesitate to ask.