C.A. for thickness of nozzle-API 650

[farzam]

Hi All,

In Api 650, the min. required thk. for nozzles are specified. I do not know if the corrosion allowance has been applied to the mentioned thicknesses because the specified thicknesses are high. please let me know if the C.A is specified by the purchaser it must be added to the thk. which mentioned by API.

Thanks in advance

 

[xema77]

In previous editions of API 650 there used to be a note indciating that CA should be applied to the nominal nozzle thickness indicated in the table or the minimum calculated thickness. I do not know why this was removed, however I still use this criteria.
Nozzle thickness shall be the larger of the thickness inidcated on the table or the minimum calculated thickness + CA.

 

[IFRs]

The purchaser specifies corrosion allowance (if any) - see 5.3.2.3

For nozzle necks, any specified nozzle neck corrosion allowance shall, by agreement between the Purchaser and the
Manufacturer, be added to either the nominal neck thickness shown in Tables 5-6a and 5-6b (or Tables 5-7a and 5-7b), or to the minimum calculated thickness required for pressure head and mechanical strength. In no case shall the neck thickness provided be less than the nominal thickness shown in the table.