Re: [MW:22093] Re: Buckling on floating roof

Dear Mr. Kumar,

Do you have the settlement readings of bottom plate before filling and after draining?. The differential settlement of bottom plate leads these kinds of waviness even it is fixed roof especially large dia tanks.

As per Clause 7.3.6.6 of API 650, there is no restriction on the bottom settlement. If the differential settlement is more than 13 mm, we have to record it and submit it to the client for review.

In 7.3.6.8 the uniform settlement is allowed up to 50 mm. Then we have to think about the effect of the bottom settlement on either fixed or floating roof.

There is no harm in this regard. Please check the rim space between the outer rim and the shell. It should not be harmful to the movement of floating roof. Hope it will not be.

வாழ்க வளமுடன் என்றும் நலமுடன்

LOVE EVER HURT NEVER

Muthusamy.S

அமீரகம்

On 11 October 2014 12:25, Kumar <sk7920541@gmail.com> wrote:

Hai,
Pls. note the material of construction is A 283 Gr.C. (also attaching
2 more snaps for reference).
Regards,
Kumar
On 10/11/14, Kumar <sk7920541@gmail.com> wrote:
> Dear All,
> For a storage tank as per API 650 construction (dia- 72 mtr, height-
> 22 mtr), the external floating roof have found with some buckling &
> waviness which is more noticable after the hydrotest. since the roof
> is resting on the fixed legs in the bottom plate, this might be due to
> the settlement of foundation during hydrotest. anyhow, sub-con is
> declining to rectify this as there is no criteria in 650 for floating
> roof. Kindly share your views(few snaps attached)
> Regards,
> Kumar.
>

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