calculation for t(required) (Appendix 2 flanges, cone shell junctures

[LSThill]

Do you know how components that don't have a direct calculation for t(required) (Appendix 2 flanges, cone shell junctures nozzles etc) are handled?

In-service Inspection of Pressure Vessels Pare RB

RE-3236 REMAINING LIFE CALCULATION

Where the corrosion rate controls the life of the pressure vessel, the remaining life shall be calculated by the following:

t (actual) - t (required)

Remaining life (years) = -----------------------------

Corrosion rate

Where,

t (actual) = thickness in inches (mm) measured at the time of inspection for the imiting section used in the determination of the t (required).

t (required) = minimum allowable thickness in inches (mm) for the limiting

section of the pressure vessel or zone. It shall be the higher of the following:

1. The calculated thickness, exclusive of the corrosion allowance, required for the pressure relieving device set pressure, static head or other loading and design temperature or

2. The minimum thick permitted by the provision of the applicable section of the original code of construction

Corrosion

Rate = inches (mm) per year of metal removal as a result of corrosion

tOriginal - tactual
_________________________
years

Leonard@thill.biz

 

[Raydel]

If you use reliable software, such as CodeCalc, it is very easy to design flanges in accordance with ASME Appendix 2. With regard to remaining life, the more sophisticated way to accomplishing this in accordance with API579 which considers fitness for service. With regard to shells and heads CodeCalc has this provision built in.

 

[LSThill]

Raydel (Mechanical)

I have CodeCalc dose not meet the NBIC requirements!

RE: "THE NATIONAL BOARD INSPECTION CODE (NBIC), ANSI/NB-23, DATE OF ISSUE: DECEMBER 31, 2002

Not design the above but rating (RB-3236): t(required) (Appendix 2 flanges, cone shell junctures nozzles etc) are handled?


Leonard@thill.biz

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