Corrosion from HCl and Cl2
Corrosion from HCl and Cl2
(OP)
Hi,
I need to know if the gas with the following composition and in present of HCl and Cl2 is corrosive for the stainless steel.
Composition
H2O (1) 1.47 % vol
N2 81.29 % vol
CO2 16.45 % vol
O2 0.79 % vol
Cl2 2 average / 20 max ppm vol
HCl 2 average / 20 max ppm vol
Total Mass Rate 19159 kg/h
Total Molar Rate 627.75 kmol/h
Mol. Weight 30.52 kg/kmol
Op. Pressure 3.60 / 5.30 bar(g)
Max. Temperature 39°C
Reg. Temperature 230 °C
(1)Saturation Water @ 3.60 bar g and 39 °C
Thanks
I need to know if the gas with the following composition and in present of HCl and Cl2 is corrosive for the stainless steel.
Composition
H2O (1) 1.47 % vol
N2 81.29 % vol
CO2 16.45 % vol
O2 0.79 % vol
Cl2 2 average / 20 max ppm vol
HCl 2 average / 20 max ppm vol
Total Mass Rate 19159 kg/h
Total Molar Rate 627.75 kmol/h
Mol. Weight 30.52 kg/kmol
Op. Pressure 3.60 / 5.30 bar(g)
Max. Temperature 39°C
Reg. Temperature 230 °C
(1)Saturation Water @ 3.60 bar g and 39 °C
Thanks





RE: Corrosion from HCl and Cl2
RE: Corrosion from HCl and Cl2
Tom
Thomas J. Walz
Carbide Processors, Inc.
www.carbideprocessors.com
Good engineering starts with a Grainger Catalog.
RE: Corrosion from HCl and Cl2
RE: Corrosion from HCl and Cl2
The data provided by you indicates there is possibility of water saturation at the max operating temperature. Both Cl and HCl,in dry and gasesous form are not so corrosive. But the situation if different when they are wet.
S.S 316 possess adequate corrosion resitance in dry chlorine and HCl environment. However the following engineering guidelines would be of help:-
-Use 316L base metal(Max C-0.03%)
-Use E/ER-316L welding consumable,max "C" as above.
-Use properly qualfied weld procedure,(consumables as above)and interpass tenperature not exceeding 175degC-Avoid Sensitization.
-The above shall be monitored during fabrication.
-Regulate the saturation limits, such that the environment never becomes wet.
If there are concerns on process parameters then upgrading from 316S.S to Nickel based alloys would be advisable.
The following guide from NIDI would provide you good information, on materials selction.
Thanks
Pradip Goswami
RE: Corrosion from HCl and Cl2
Please re-read your post and re-state the normal and maximum exposure temperatures. I presume your "maximum" is a minimum of 39 C (i.e. saturation at your pressure).
316/L SS is insufficiently resistant to survive repeated exposure to this partial condensate long-term in my opinion, regardless how good a job you do during specification/fabrication. You may be able to mitigate this by other means, i.e. by blowing the line out with dry gas when it is cooling down.
RE: Corrosion from HCl and Cl2
RE: Corrosion from HCl and Cl2
hope this can help u
S
Corrosion & Rust Prevention Control
RE: Corrosion from HCl and Cl2
Under saturation condition, the concentration of the chloride in aqueous phase is 0.1% in weight.
So,I think that the 316L is suitable for may plant.
Akfirm
RE: Corrosion from HCl and Cl2
Under saturation conditions, the concentration of the chloride in aqueous phase is 0.1% in weight.
So, I think that the 316L is suitable for my plant.
Akfirm
RE: Corrosion from HCl and Cl2
If you can avoid condensation completely by procedures or mitigate it by other means, 316 might still be OK.
RE: Corrosion from HCl and Cl2
also in reg (regeneration?) you'll have a temp of 230°C, and at this temperature you can also have CSCC, chloride stress corrosion cracking on SS 316L..
I'll select a more corrosion resistant alloy like nickel alloys.
S
Corrosion & Rust Prevention Control
RE: Corrosion from HCl and Cl2
2205 may be good enough, I would look into corrosion data on this grade and see if it looks like a fit.
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Plymouth Tube
RE: Corrosion from HCl and Cl2
Wich is the pratically solution for the piping in this case.
Carbon steel or Duplex material?
Wich is the mechanism of corrosion of clorides on carbon steel? If there is an absence of oxigen is the corrosion inhibited? Thank's for your answer.
P.S. Naturally the duplex is the bettere choice, but is carbon steel applicable?
RE: Corrosion from HCl and Cl2
Injection water is usually deaerated seawater or freshwater, and this will lower the corrosion rate on carbon steel to a negligible value.
Water is considered deaerated when the oxygen level is, as per Norsok M001, below 20 ppm.
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in your case seems more a production/formation water, the chlorides conc is very high, and you have to assess the corrosivity considering co2 content and other corrosive.
S
Corrosion & Rust Prevention Control