Vapor fraction and H2S partial pressure

[CoCoE]

I would like to seek the opinions on below things.

In a slug catcher,

Top: Gas line (with H2S partial pressure approx 15 psi, CO2 approx 25 psi)
Bottom: Sour water (Zero vapor fraction, 99.8% water, 0.02% H2S+CO2)

In such a condition, for selecting the material for the bottom piping, how to consider H2S partial pressure? I feel that I must consider the Top gas piping process parameters as equilibrium gas phase. But some people conflict this by saying as there is no vapor fraction, pH2S is very very low, and this is completely in aqueous phase.

What is the correct method?

Kristy

 

[SJones]

Refer to C.2 of ISO 15156-2, particularly the NOTE under list item a)

Steve Jones
Corrosion Management Consultant

http://www.linkedin.com/pub/8/83b/b04

All answers are personal opinions only and are in no way connected with any employer.