Caustic Corrosion Question

[edgar_box]

Hello gentlemen,

The client wants to PWHT 2"/sch 80, A106-B pipe welds to make them more resistant to caustic corrosion. Just out of curiosity I am wondering if that is the best measure or if they would be better off using a different material all together.

Thanks

[duazo2009]

Hello gentlemen,

The client wants to PWHT 2"/sch 80, A106-B pipe welds to make them more resistant to caustic corrosion. Just out of curiosity I am wondering if that is the best measure or if they would be better off using a different material all together.

Thanks

edgar,

The PWHT on 2" Sch 80 pipe, A106 Gr. B is a service requirement, refer SAES-D-001 as stated.,

11.4.1 Apart from Code requirements of PWHT for carbon and low alloy steels, the following process services require PWHT. Other process conditions may also require PWHT, as determined during the project design or as specified by the Saudi Aramco Engineer as defined in this standard.
1) All caustic soda (NaOH) solutions, including conditions where caustic carryover may occur (all temperatures).
2) All amine solutions, at all temperatures excepting the following:
a. Diglycol amine (DGA) solutions below 138°C design temperature
b. Rich amino di-isopropanol (ADIP) solutions below 90°C design temperature
c. Lean ADIP solutions below 60°C design temperature.

Cheers,

duazo2009