Material Selection for Piping (NACE vs. CRA)

Apart from the other nasties, chloride level in water 14,500 mg/l isn't far off seawater. That will soon go through carbon steel.

This really needs non-metallic materials in contact with the fluids. GRP is one possibility and plastics such as PE, PP, PVC, PVDF would be another.

NACE will just help you define CRA's. The comparison you seek is moot!

Get in contact with NACE and look at their different standards.

20 Year plant life is going to be a stretch unless you can tell exactly what is going to happen over the 20 years.

This will have to include cleaning processes and any predictable change in the surrounding and work processes.

I do not think anybody can guarantee you 20 years. Good luck!

What is the application, RO? Sounds like it from the pressure.

I agree with CODEMASTER... this chloride ridden stuff will corrode many, if not all CS materials.

Austenitic SS materials are also out of the question....

GRE and FRP, plastics will not give you 20 years life....

Time to call in the corrosion resistant "bad boy".... Hastalloy C..... also Known a C276.

If your massflow is high, (and your pressure certainly is) you may need large diameter piping. What is your calculated pipe size ?

Carbon steel piping with C276 internal cladding would be my choice.

Please respect us and tell us of your final decision.

http://www.crystalindustrial.in/download/cladding.pdf

Watch out large pipe and high pressure might not go along very well together!

Calculated pipe size is 10''. Can you please share the basis for elimination of Austenitic grades SS 304 and 316 also 22 Chrome and 25 Chrome can be used but we are trying to optimize the cost.

Can you give more details of the fluids? You refer to raw gas and water. Do they flow together, or in one pipe at different times, or in 2 separate pipes? Is the pressure 1175 psig same in all cases?

Cupronickel should be OK for corrosion (water case), but only good for 20 barg ~ 300 psig as standard. Maybe higher pressure range is available, I don't know offhand.

What I have done is that I have gone through the piping material specification charts of some major clients (operating companies) of my company (O&G constructors) and looked for something matching your fluid. Found this,

Inconel-625 is the best suit where the service is Corrosive Hydrocarbons (H2S+C02+Chlorides: Heavy Corrosion) and the fluid is, what they call "Production Gas" which has Gas+Liquid+Salt Water

SS TP-321 with zero C.A. is specified for Corrosive Hydrocarbons (CO2+H2S: Heavy Corrosion). But since there are chlorides.. SS is susceptible to Chloride Stress Corrosion Cracking (CLSCC) and periodic inspection is required for monitoring the same. Use of this material depends on your client's material selection philosophy and willingness to do so by plant operations dept.

I don't think any client will let you use CS or SS unless you produce extensive documentation with supporting calculations for that. So Inconel may be the option for you. GRE may not take that pressure in my opinion.

I have the pipe class with me if you need a copy. Just put your Mail Id here.

Hope that info helps.

Thanks Shaff for your time and answer.

Can you please share Piping material Specification?

Email Removed- Cr4 Admin.

Thanking in advance

sent. check ur mail

Thanks Mr Shaff, I have received Piping spec.

Don't use your e-mail in the open forum. Better use the Personal Messanging system.

Ups is this PMS?