peeyar1: Re your below question regarding the use of 300 series stainless steels in CO2 and H2S service, in general the 300-series stainless steels should be resistant to your stated concentrations of carbon dioxide and hydrogen sulfide. However, you need to consider whether chlorides are present before selecting these materials. Chlorides can pit and crack the 300SS depending on the concentation, temperature, deposits, etc. Hope this helps! David Hendrix The Hendrix Group Inc. >We are working on natural gas compression project, where the >gas, predominantly, Methane, is saturated, having 6% CO2 and >100 ppm of H2S. The gas enters the compressor at a suction >pressure of 807 psia @ 144 deg F and the discharge pressure >of the compressor is maintained at 909 psia), the >corresponding temperature is 280 deg. F. We are using after >cooler to bring gas temperature down to 122 deg. F in one >case and in the other, it is going down to 118 deg. F. The >compressor has inlet filter separators, which can remove >droplet, greater than 1 micron size with an efficiency of >98.6%, with 3 micron size, 99.9%. While working on the >material selection for this project, we have following >questions for our better understanding the corrosive nature >of the service and the suitability of the material being >proposed: >> >> 1. Can we use austenitic stainless steel (SS 300 series), where our temperature is at or above 60 deg. C? The partial pressure of H2S varies, (with the operating pressure) however, is always less than 100 kpa or 1 bar (absolute). >> 2. Can we use vessel internals (like trays, demister, cyclone tubes, etc.) being non pressure retaining in SS 300 series constructions, where the H2S partial pressure is at or above 100 kpa (absolute) and the temperature is above 60 deg. C? >> 3. Can we consider vessel internal cladding as non pressure retaining and therefore can use SS 300 series cladding material where the H2S partial pressure is at or above 100 kpa (absolute) and the temperature is above 60 deg. C?

the only known material to resist this corrosion is calorised pipes. You can get these from us