Damage mechanism for CI Piping used in NH3 and CO2 Service 1

[rifa92]

Hello everyone,

We are using CI piping for fluid service containing NH3,CO2,H20 and H2S. The fluid composition is as follows:
NH3 = 0.402 kg/m3
CO2 = 0.255 kg/m3
H2O = 0.128 kg/m3
H2S = 0.0003 kg/m3
Temperature = 60-80Celcius
Pressure (psi) 14.7

The CI piping is suffering from thickness loss, pitting and pinholes. The corrosion of loss is not uniform and it is mostly localized. What could be the most possible material to shift too?

Thank you.

 

[Dhurjati Sen]

Concrete lining on the inside of the CI piping is required.

DHURJATI SEN
Kolkata, India

 

[Chumpes]

I guess this is full vapour system : in absence of chloride ions (or HCl) you can investigate the selection of SS 316L.

 

[EdStainless]

I presume that this is in water?
What is the Cl level?
Are your concentrations based on the total mass flow?
What is the total flow?
Long term the CO2 will attack concrete.
How long do you expect this to last?
5yrs or 40yrs?


= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed