High Chloride in Stormwater 1

[jpuy]

Hi,thought you might be of help.

Picture a 5km man-made island with extensive stormwater network.
At the moment, it is already operational. Open for public use.
Currently, we are facing High Chloride (40,000-70,000 ppm) in stormwater that is showing potential major corrosion problem on our pumping station.

We uses materials such as:
1. Stainless Steel 316L
2. Alloy 1.4122 (X39CrMo17-1) -15% Cromium. The same equivalent corrosion resistance with SS 316L. (as stated by Manufacturer)

We noticed Alloy 1.4122 easily corrodes heavily. While SS 316L already showing signs of corrosion especially on bolts.

We suggest to replace all materials in duplex (SS 904L).

Appreciate your inputs on this.

Thank you.

 

[bimr]

How large are your pumps? Is it possible to use non-metallic materials?

 

[jpuy]

Thank you for the feedback.

Its a 215KW Pump and supplier confirmed duplex material used on pump material.

We are much worried on the ancillary pipes & mechanical screen chains.

I have attached actual photos to help you better understand the current scenario.

Thank you.

 

[bimr]

Use of 904L seems to be a reasonable solution when the pump will be exposed to high chloride concentrations. Users have found that 904L will allow an acceptable service lifre when exposed to high chloride. Refer to the paper:

NiDI 11 003 "Guidelines for Selection of Stainless Steels for Marine Environments, Natural Waters and Brines"

http://www.stainless-steel-world.net/pdf/11003.pdf

 

[jpuy]

Thank you for your valuable input.

Appreciate the help.