A333 vs 304SS for low temp, high pressure ethylene

[Macossay]

Hi. We bring in ethylene through a 2" sch 160 pipeline, at pressures up to 1400 psig. The pipeline is A53 carbon steel, with a minimum temperature rating of -20F.

In the event of a sudden depressurization, the temperature could drop as low as -40F. So we want to replace the pipeline with something rated for a lower temperature.

That seems to leave me with a choice of A333 carbon steel or austenitic stainless. Is one preferable over the other? I'm particularly confused about Charpy testing -- various readings seem to contradict each other as to whether I need to do it on one or the other, or both. What do y'all think?

Many thanks,

John

 

[iainuts]

Hi Macossay,
-40 F isn't considered cryogenic. I think you'll find the Piping & fluid mechanics engineering forum a better location for your question. Try posting your question here:

http://www.eng-tips.com/threadminder.cfm?pid=378

 

[Macossay]

OK