Allowable chloride content in CS pipes

[mechatronic]

Dear Sirs,

Can any one tell me what is the maximum allowable Chloride content in water, for which we are using Carbon steel.

The water in this area has high chlorides .

Regards,

 

[mrtangent]

Mechatronic,

What type of Chloride are you using. HCl or Cl2 and what is your temperature range ?.

The other thing which is important is what the shutdown / maintenenace stratigy on the linework you are using. If you have a annual shutdown with moderate corrision it may be accepable to use CS pipes and change them out every year - and in some cases thats cheaper than using a corrision resistance alternative. We have high Cl content and certain parts of the plant we do use CS but change them out on a set out frequency.

If you are using HCl I would say, you need to be below 40C and have less than ppm levels of Cl. I think there are tables of corrision data for HCL in carbon steel environments - ie how much thickness you lose per year. They maybe in the US mechanical standards. Those you could use as a guide.

Hope this helps.

James

 

[mechatronic]

James,

Thanks for your prompt reply .

The present Chloride content is 15PPM as caco3 and HArdness is around 79 PPM as Caco3

Kindly let me know is it recommended to use Carbon steel pipes for the same . A recommendation on material quality will help me a lot
Regards,
Mechatronic

 

[patrickraj]

For this level of chloride there will not be any problem. We have 1600 cl as caco3.
In 30- years no problem was faced.(exchangers,pipes etc)