Corrosion allowance required for Steam piping
Corrosion allowance required for Steam piping
(OP)
Can anyone please clarify the following?
We have selected SA335 P11 pipe material for the superheated steam piping (for the operating temp of 470 deg C). The piping was designed to ASME B31.1. The question is, what should be the minimum corrosion allowance considered while selecting the pipe thickness?
We have selected SA335 P11 pipe material for the superheated steam piping (for the operating temp of 470 deg C). The piping was designed to ASME B31.1. The question is, what should be the minimum corrosion allowance considered while selecting the pipe thickness?





RE: Corrosion allowance required for Steam piping
RE: Corrosion allowance required for Steam piping
For power piping, there may be 2 exceptions to that rule- the thin wall piping downstream of teh HP bypass spray attemporator may suffer erosion if not provided with an inconle liner, and for feedwater piping downstrem of the BFP dishcarge nozzle and at elbows that may suffer FAC . Those exceptions also need to incorporate routine ( bi-annual) UT of wall thickness to confirm the erosion rate has not removed excessive wall thickess.
RE: Corrosion allowance required for Steam piping
Thanks a lot for your responses. Based on your feedbacks, I have justified to the Client.
JB
RE: Corrosion allowance required for Steam piping
It has become common to see the use of higher Cr grades in mild FAC locations and Ni alloy ID weld overlay in places where it may be serious.
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