Can superheated steam or saturated steam be used with 304 pipes?
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Question: For pipes carrying 10 kilograms of saturated steam, or superheated steam at 425 degrees with a pressure of 5 kilograms, can 304 stainless steel be used as the material for such pipes? I’m sure the temperature levels won’t be a problem; it’s just that I heard from an experienced engineer who was talking with a manufacturer that there was a factory which encountered leaks due to using this material. Because stainless steel pipes are sensitive to chloride ions. This message is no longer verifiable. Originally, overheated steam should have been handled using 15CrMo material; however, since the manufacturer had a large surplus of 304 pipes, and 15CrMo requires heat treatment, it was asked whether 304 material could be used instead.
The pressure here isn’t very high either. Is it possible to determine the chloride ion content in the steam? If it exceeds 50 ppm, then 304 steel cannot be used
Is your answer based on a book or on practical examples?
It comes from a standard; I’m not sure exactly which one. You can look it up online
The water used in boilers is soft water (i.e., free of hard ions such as calcium and magnesium), so the chloride ion content in its steam condensate may exceed the allowable limit for austenitic stainless steel (less than 25 ppm). If the condensate water is analyzed and the chloride content is less than 25 ppm, then 304 can be used; otherwise, as that engineer said, the pipes will corrode. For your reference