Dear DMI, Thank you for your reply. The decission to change the CS to SS was originally recommended by the furnace manfacturer when they have found corrosion deposits in the system. I agree with you that investigation to find the root cause should take place. However, the furnace was under the resposibility of the furnace supplier at the time. The situation deterriated recently and I have no choice other than to change the pipes to SS due to the criticality of the furnaces. My findings on the other hand was that the reason for the corression was because the system was subjected to be open circuit during the PMs, air (Oxygen) have contributed to the phenomenna. Although the system is supposed to be a closed circuit system, it was prudent that Operation do leave the system open. The furnace supplier have never came to this conclusion but they encouraged us to go a head changing the pipes to SS. Going back to the original question, given the parameters to select the SS SCH. 10 at the pressure 3 to 4 bars for the pipe size 4" and 5" for a close system cooling system, can any body give another etailed calculations confirming my selection? Thanks again for your support and constructive contribuation. Regards, Jassim

Dear DMI, Thanks a million for your recommendation. However, would you kindly send me the link to reach to the recommended ASME site please. I will definately post you with latest... Best regards,