maximum plate thickness for API 650 tank

[rudiawan .]

friend..
i am calculating the plate thickness for API 650 Tank, and get the result shell thickness for course no 1 is 22 mm material is A36

refer to 4.2.1.4 Shell plates are limited to a maximum thickness of 45 mm 1.75 in. unless a lesser thickness is stated in this standard or in the plate specification.

but if we look at table 4.4a for material A36M Group I As rolled semi killed , there is a notes that plate thickness shall be less than 20 mm

anybody can advise which should i follow

 

[LittleInch]

Well it says <= 20mm so either choose a different material or use A36 as a group II material?

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

 

[JStephen]

Ditto to the above, consider using A36-Mod meeting Group II requirements. That material is commonly available.

 

[rudiawan .]

thanks for your advise