ECE High Pitting Rate
ECE High Pitting Rate
(OP)
Dears,
I have a question about possible mitigations and corrosion control for this steam I modeled on ECE. A 4" pipe is used to transport sour gas from HP compressor discharge KO drum (Dry Gas) to a water well to left water to a degassing vessel. Is it possible to use CS with 3.2 mm corrosion allowance for 20 year design for the pipe?
H2S Mole% 0.5
CO2 Mole% 9.8
Gas flow rate: 1.1 MMSCF
Crude Flow rate: 0
Water Flow rate: 0 but ECE can only take 0.1 Sm3/d as a minimum input.
Pipe size: 4"
Temp: 72 C
Pressure: 500 psig
Cl-: 50 ppm
The pitting rate is coming 15 MPY which is a very high value. I believe this is caused by the low water speed in a 4" pipe. But now water will condense in the pipe as the pipe is also electrically traced to prevent any condensations. Can we justify the use of bare CS in this case?
I have a question about possible mitigations and corrosion control for this steam I modeled on ECE. A 4" pipe is used to transport sour gas from HP compressor discharge KO drum (Dry Gas) to a water well to left water to a degassing vessel. Is it possible to use CS with 3.2 mm corrosion allowance for 20 year design for the pipe?
H2S Mole% 0.5
CO2 Mole% 9.8
Gas flow rate: 1.1 MMSCF
Crude Flow rate: 0
Water Flow rate: 0 but ECE can only take 0.1 Sm3/d as a minimum input.
Pipe size: 4"
Temp: 72 C
Pressure: 500 psig
Cl-: 50 ppm
The pitting rate is coming 15 MPY which is a very high value. I believe this is caused by the low water speed in a 4" pipe. But now water will condense in the pipe as the pipe is also electrically traced to prevent any condensations. Can we justify the use of bare CS in this case?
RE: ECE High Pitting Rate
And we know that operation will never allow that.
Just know that a single failure may render the line unsafe.
I have seen this so many times with tracing, chem injection, impressed current, and others.
One failure will either force a system shutdown or risk consuming 100% (or more) of the CA.
= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed
RE: ECE High Pitting Rate
Steve Jones
Corrosion Management Consultant
www.linkedin.com/in/drstevejones
All answers are personal opinions only and are in no way connected with any employer.