Super-critical sour CO2 service

[tovi]

Can someone tell me what special requirements need to be considered for a sulfa treat vessel that is in "super-critical sour CO2" service?
The vessel will operate at 1500 psig and 120 F and be fabricated from SA-516 70 normalized material, post weld heat treated and coated internally with belzona.

Thanks

 

[gr2vessels]

tovi,
first please clarify the supercritical bit, wher is it?
The grade 70 is probably the borderline material, you will have to be very carefuly monitoring the weld hardness to remain less than 22 HRC (refer NACE MR 0175). Don't relay on the PQR's, ask for detailed production weld tests. Also, the sulphur content in the steel is restricted, refer to the mentioned standard. I hope you specified 1/4" corrosion allowance. The mentioned coating is for estetics mainly, I would suggest lining or better still, CRA weld overlay. Other than that, nothing special.
cheers,
gr2vessels

 

[grampi1]

Make sure the 516 Gr70 is 0.005 or less V+Nb, B below 0.0005 and then CE(IIW) less than 0.43. This will faciliate staying under 250HV after PWHT. Also your option to ask for HIC qualified even though internally coated, as insurance.

Will you steam out for shutdowns? If your Belzona choice rated for steam out?

Your pepared for coating touch ups every 5 years? If coating flakes off, won't go in to a compressor I hope.

 

[dcasto]

do you plan on injecting water?