A tank that needs hot tapping at multiple elevations has liquid level that results in hoop stress of 15,000 psi. The material is known toughness, but I'm still leery of welding on the shell with that high hoop stress. API 653 states that materials of unknown toughness shall limit hoop stress...
I'm trying to better understand the equations in E.6.2.2.3.
Can someone help me understand what's in the coefficient 10^6 of the allowable stress equation 10^6*t/D? I think it must be some derivation possibly including 1.33FY/(12D/t) (1.33 for ASD times yield stress, all divided by D/t)...
I'm confused by the ASME IX, 403.2, "the max thickness qualified is the thickness of the coupon", and 403.6, "the minimum base metal is T/2 when T<1/4".. Compare that to the table 451.2, where a coupon over 3/8 is qualified for thickness range from 3/16 - 2T.
I want to develop a WPS that...
I will appreciate receiving experienced perspective with tanks resting on sand (inside the ringwall), vs resting on concrete. Have you seen many tanks that rest on concrete (inside the ringwall)? Are you aware of any benefits of using one, or the other? Sand may help with drainage. Sloped...
Anyone have a chart that suggests column seal material by application?
I have a Naptha storage tank with internal floating roof. I'm looking for guidance in replacing the column seal material. I had a recommendation to use teflon, but I think teflon is too stiff. I appreciate if anyone is...
I'm having a difficult time understanding the distinction between ring wall overturning moment (Mrw) and slab overturning moment (Ms). Mrw is less, and defined as the portion off the total moment that acts at the base of the shell perimeter, Ms is defined as the total overturning moment acting...
I'm using an 1/8 inch EPDM gasket for liquid service (4' head for- a tank launder). It's economical to provide the large gasket in sections that require dove-tailed joints. I'm faced with the option to simply rely on compression of the joint for sealant, of we could go the extra step and glue...
The customer has offered to level ground and pour a temporary work pad (200 ft X 200ft) for the tank erector to fabricate tanks, that will be placed on final foundations after fabrication.
No subgrade study has been performed. Loads are expected to be less than 1000 psf. Is it enough to...
API 650, Figure 5.7a, detail b, indicates that the corner-corner weld of the flange to the neck shall be the thickness of the thinner member joined however, Figure 5.12, detail b, indicates that the corner-corner weld of the flange shall be the thickness of the thinner member joined, with a max...
Can anyone help me in finding the above referenced document? It's referenced in a tank design standard but, I can't find it's source.
I'm interested in quantifying the moment in a wind girder due to lateral platform loads- I would appreciate if anyone can share a method for analysis that they...
Can anyone weigh in on the usefulness of PIP STE03020 guidance regarding ring wall foundation design? I would appreciate additional resources if anyone would share.
I feel it's preferable to grout beneath an anchored tank prior to hydro-testing however, if a schedule advantage is present, would you allow a hydro-test prior to grout? I'd appreciate advice from past experience- has anyone been faced with a similar decision? What was the outcome?
Why are there two versions of the equation listed for Ai/Ac in E.4.6.1? If I use Ss/S1 the two equations equal (just as is suggested in the appendix) but, why substitute? It seems like if I can use the second equation, I have enough info to use the first. Is it simply a matter of breaking out...
I'm looking for a transparent method of determining allowable loads on tank shell by brackets, for example, a platform support bracket. I'm familiar with a method that's been passed down; it calculates the max allowable moment, as M=1390t^2(6+6BL+(B^2)(L^2)). I'd like to know what's in the...
I'm trying to gain a better understanding, and form parallels, of allowable stress formulas listed in AWWA D100 (eq 3-11) and API 650 (E.6.2.2.3-2a/2b). How are these formulas derived? AWWA D100 eq 3-11 is similar to Boardmans's equation (S=Et/29r(2-200t/3r)), and these are both conservative...
I'm looking for a transparent method of determining allowable loads on tank shell by brackets, for example, a platform support bracket. I'm familiar with a method distributed by a tank mother company (C#!) that's been passed down; it calculates the max allowable moment, as...
I don't beleive API 650/AWWA D100 requires the deduction of corrosion allowance when calculating the overturning moment and overturning ratio of ground supported tanks. However, I've seen seen designs in which the CA is deducted from the tank material weight, resulting in the requirement of...
I'm designing a tank with an allowable stress of 38000 psi. Can anyone help deconstruct the coefficient "1/10000" in the API 650 equation for determining required section modulus for stiffeners on p.5-70? Is there an allowable stress in there that I may adjust for the high allowable I'm using...
