Can valves made of 317L material be used in the sampling pipelines for SO2 and SO3 at 650 degrees in sulfuric acid plants?
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This post was last edited by Ge Cao Zhi Ji_o9818 on 2015-11-19 09:16. QTY, Valve Type, Temperature (Celsius), Pressure (Bar), Application Details: 1 Ball Valve, 25, 30, 00.4 – Used for testing SO2 & SO3 gas samples in sulfuric acid plants. 9 Ball Valve, 25, 50, 00.4 = = = = 2 Ball Valve, 25, 55, 00.4 = = = = 3 Ball Valve, 25, 65, 00.4 = = = = 2 Boiler Blow Down, 25, 30, 020 – Used for draining water from inside boilers. These valves are used in the SO2 and SO3 pipelines in sulfuric acid plants; one end of each valve is connected to the pipeline, while the other end is used for sampling, so as to conduct tests on SO2 and SO3 gases. Our technicians have worked in sulfuric acid plants; the recommended materials are as follows: 316L is suitable for temperatures of up to 300 degrees Celsius, while 317L is suitable for temperatures of 500, 550, and 650 degrees Celsius. We are a valve manufacturer and don’t know much about this; the corrosivity of SO2 and SO3 is probably not as strong as that of sulfuric acid. I hope an expert can offer some guidance! A thousand thanks @yunsanapo.
I asked technicians from other research institutes; when used in pipelines, since the gas temperature is stable, SO2 and SO3 generally don’t cause much corrosion, so it’s sufficient as long as the material can withstand high temperatures. When used in sampling, the gas may cool down, forming acid mist upon contact with water, which can produce sulfuric acid or sulfurous acid; moreover, high temperatures possess strong corrosive properties. With a high sampling frequency, 316L and 317L will corrode more rapidly; it is recommended to use 904L. With a low sampling frequency, 316L and 317L can be used