Cost of Api650 vs AWWA D100 1

[farhadsh]

Hi, I am looking for some insights for this topic.
A Fire water storage tank to be constructed and installed in a mining site with 20 m dia by 20 m height. I am wondering which standard api650 or AWWA D100 require thicker shell for this case ? Which standard will be cheaper on overall storage tank cost?

 

[Geoff13]

Are there any local regulations that will require using NFPA 22 (Firewater Tanks)?

You can ask your tank vendor to quote both Codes. API 650 has ~10% higher allowables than AWWA D100 Section 14, so you might guess it would be cheaper.

 

[LittleInch]

Apparently it's API 650. We had this issue on another question recently.

Someone has even written a paper on it!

https://ui.adsabs.harvard.edu/abs/2023AIPC.2592e0004I/abstract

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[MJCronin]

faradash,

I do not believe that you will find a significant cost diference between the two construction codes, ..... however

SOME FACTORS THAT STRONGLY AFFECT TANK COSTS ARE:

--- Tank internal/external coatings - These can easily cost as much as the tank and should be quoted along with the tank

--- Tank foundation selection - Concrete Pad, concrete ringwall, or clay foundation costs are significant

--- Tank Cathodic Protection and Leak Detection

--- Tank Location -- Massive Fire water tanks cannot be placed anywhere - some (swampy) locations will be very expensive

I would very much like to hear to thoughts of others on this topic ...

MJCronin
Sr. Process Engineer

 

[fel3]

If the site is subject to high seismic forces, then a 20-m dia x 20-m tall tank will require anchorage because of its aspect ratio.

============
"Is it the only lesson of history that mankind is unteachable?"
--Winston S. Churchill

 

[HTURKAK]

For the subject tank size ( 20 m dia by 20 m height ) , the foundation, roof structure ,bottom plates , painting , CP will be similar for the design as per API 650 or AWWA D100 . However the shell design may differ .

Assume ASTM A36 for the shell plates

Acc. to AWWA D100
Allowable stress for AWWA 19,330 psi
Shell thickness t = 2.6hpDG /(sE)
hp = the height of liquid from top capacity level to the bottom of the shell course being designed, in feet


Acc. to API 650
Allowable stress for A36 23,200 psi
Shell thickness as per 1ft method td = (2.6D(H – 1)G)/Sd +CA
Moreover , with the 1-foot method , the required thicknesses is calculated at design points 0.3 m (1 ft) above the bottom of each
shell course.

The shell thick. would be less for the design as per API 650 . However, the workmanship , inspection and test requirements for API are more stringent.

Just saying..


Use it up, wear it out;
Make it do, or do without.

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