Does API 650 allow for different length shell plates on the same course. ie could you use 4 plates of equal length and then one small piece of less than a meter to form the shell?
Is there any problem with having 2 different grade steels on an API 650 Storage Tank?
We want to weld a bottom course of A537 and all other courses of A283 and want to know if there could be any detrimental effects caused by this?
I understand that they may distort at slightly different rates...
I would like to ask for some advice on welding sequence on API 650 storage tanks which I know is not covered in the standard.
When erecting a storage tank with a crane we have typically fully welded the verticals of one shell course before welding the verticals of the course above and then the...
In API 650 section F.7.5 states that;
"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 greatest of the following:
a. The uplift produced by 1.5 times the design pressure of the tank...
I would like some help in sizing a curb angle due to the tension caused by the rafters.
I have the attached as a sample which is a rafter roof for a 9m Dia tank using an IPE 160 as the rafters with a 1:5 slope.
1) I would initially like to ask a seemingly simple question as to how the...
Does anyone have any guidance on how a machine shop could become a certified machine shop by API.
We are in the middle of Africa where there are currently no certified machine shops and very little information to pull from on how to go about becoming certified. We are in particular targeting...
In the past we have always earthed storage tanks into a "earthing pit" right next to the tank... We have just come across a consultant who is insisting that all earthing should be done outside of the bund wall as when it rains the whole bund area will become charged.
What are your opinions on this?
Probably a simple one....
As per API 650 why does the internal design pressure of a tank have any bearing on the overturning moment? Why is only the uplift taken into account whereas the pressure would act equally in all directions so the downward pressure would cancel out the uplift.
Dear All,
If you have an open vented tank how would you go about ascertaining the internal design pressure of your tank when calculating the overturning moments? I do not want the maximum design pressure as per Appendix F but the actual design pressure.
I would guess that it is just an...
I need to design a floating suction and want to establish how buoyant the float should be. We are designing for a tank of 5.9m Dia x 7.5m High with only one single swivel elbow. This will mean that the when the tank is filled to the top the float will be submerged so I do not want to make the...
Is it acceptable to have a bottom plate joint at the centre of the storage tank. This would mean that a portion of the joint would be cut out for the sump. Would this constitute a 3 plate lap joint?
What is the maximum deflection in a beam in bending according to AISC Steel Construction Manual 13th edition. I have the manual but cannot find where this is defined? I have heard L/360 but want to be sure.
I want to design roof rafters for a storage tank and want to know the allowable...
Dear All,
When calculating the uplift loads in API 650 it refers to P = deign pressure (see Appendix F).
If you calculate P in Appendix F and the tank is small the maximum design pressure could be very high. This would mean that a large number of anchors are required even if my "actual design...
How do you go about calculating the maximum air flow through an open vent on a storage tank assuming it is a swan neck breather (so 2 elbows and 200mm of pipe) when the tank is discharging and filling?
I have heard that you should carry out a pressure loss calculation but I do not know where to...
Table 22.4.1 (a) refers to a week roof-to-shell seam. To have a week roof to shell seam do you have to comply to the frangible roof joint as per API 650 or can you just have a week roof to shell joint by grinding portions out?
My second question.... Are you allowed to fabricate an emergency...
Can someone explain to me what the exact function of the hot pass is after using an E6010 electrrode for the root run. I have heard a number of different theories but most of them seem to point at reducing the possibility of hydrogen cold cracking as the E6010 electrodes release a lot of...
Is there any problem with installing a 4" ANSI B16.5 #600 flange onto a 4" API 5L ASTM A106 Sch 40 pipeline?
The working pressure of the system is 70 bar and as per the specs for Sch 40 and #600 this should be adequate. Please advise as I have never seen a #600 flange installed onto a Sch 40...
I am trying to design a spreader beam in which will have 2 possible lifting points at the bottom of the beam (4 nos. lifting lugs). The outside lifting points will be spaced at 4,410mm c/c and the inside ones will be spaced at 2,350mm.
The lifting lugs on the top side of the beam (where the...
Why is it necessary to have such large peripheral vents and a central vent on an Internal Floating Roof as per API 650. Surely if you satisfy the venting requirements as per API 2000 that should suffice?
Dear All,
I want to size a curb angle on a storage tank based on the tension caused because of the horizontal load of the roof rafters, yet API 650 does not address this. Can anybody advise how these calculations can be done?
