Thanks for the quick response,
So, if I were to fill, let's say, 2 inches above the weld connecting to the roof plate, I would need to adjust the design calculations to account for this new level, correct?
For example, if testing according to 7.3.6.1.1 b), I would need to modify the equation...
Hi everyone,
I have a question regarding the design liquid levels in an API 650 storage tank.
The tank will store a product with high relative density. The design liquid level (DLL) for the product is limited by some overflow nozzles, which are located below the top angle. However, for the...
I believe as JStephen is saying if I try to check static hoop stresses above the liquid surface Y is negative and I would get strange values that does not represent the actual shell stresses. I am thinking to only check for hoop stress if Y is positive. Am I correct?
I was reviewing some calculation notes on this topic and noticed that when the test point is above the design liquid level, the Y value becomes negative. If I proceed with the equations using a negative Y value, I sometimes end up with unusual and excessively high thickness requirements for...
I have encountered a standard interpretation issue that has raised some doubts. According to API 650, the following is stated:
"5.9.1.3 All tanks shall be stiffened by intermediate wind girders when required by 5.9.6. Vacuum stiffeners, when required by Annex V, may be considered to also act as...
Hi, before asking the question I want to thank you for your time. I have a doubt on the standard wording.
On API 650 5.7.7.6 you calculate the nominal thickness of the bottom reinforcing plate with the equations given. Later we have a note:
tbr is the minimum thickness of the bottom...
It's pretty clear the procedure to find t2 in an inspection plane for a localized corroded area. My doubt about the procedure, once I get t2 and calculate the value of L with the 4.3.2.1.b equation. When I calculate t1, I have to get all the measurements 0.5 L on top of t2 location and 0.5 L on...
I understand. Do you belive I need to take into account only the uplift pressure using the PWR to calculate the counterbalancing weight or I also need to take into the account the moment MWS?
API 650 says this
F.8.2 The counterbalancing weight, in addition to the requirements in 5.12, shall be designed so that the resistance
to uplift at the bottom of the shell will be the greater of the following.
a) The uplift produced by 1.5 times the design pressure of the corroded empty tank...
Thanks for your answer,
The two additional lines you are adding to the graph, how do you interpolate them? Linearly on the graph or do you have to consider it is a logarithmic scale?
I did get the equations for the three original lines from a/R (they are approximate)
a/R = 0.005
KR/(E * 2 *...
Hi, I am trying to figure out how to extract the data from the P.2a to P.2l graphs. There is an example problem on P.2.9.1 and in the solution it gets a value of 3.1 x 10-4 for KR/E(2a) on Figure P.2a. I enter that figure and dont understand how to get that value. Is there a tabulated graph or...
5.2.1. b) Design External Pressure (Pe): Shall not be less than 0.25 kPa (1 in. of water) except that the Design External Pressure (Pe) shall be considered as 0 kPa (0 in. of water) for tanks with circulation vents meeting Annex H requirements
Design Pressure shall not be less than 0.25 kPa...
I'm checking the intermediate wind girder requirements as per 5.9.6.6.
Anyone know how to calculate h1 value when having multiple wind girders?
From the standard I get the following:
"h1 is the vertical distance, in meters, between the intermediate wind girder and the top angle of the shell or...
