increasing temp on A-240-304 stainless AST increasing temp on A-240-304 stainless AST Tweetybird (Petroleum) (OP) 16 Nov 17 21:24 Operations wants to increase temp rating from 200F to 450F. where do we start RE: increasing temp on A-240-304 stainless AST XL83NL (Mechanical) 16 Nov 17 21:48 Start with what? Your question is far too undetailed to expect any useful feedback. RE: increasing temp on A-240-304 stainless AST JStephen (Mechanical) 16 Nov 17 22:35 "AST" = "Above Ground Storage Tank"? If that's the case- that is a "change of service" per API-653. The increased temperature gives you lower allowable stresses and can cause some fatigue issues addressed to some extent in the API-650 standard. It may have corrosion implications that aren't addressed in API-650. It has the potential to require larger vents, depending on the operation. It may require different gaskets, vents, etc., just due to the temperature. It may require insulation, if not already insulated- OSHA personnel protection, for example, or just for economy. It may affect foundation performance. More specific question may get you better answers. RE: increasing temp on A-240-304 stainless AST Tweetybird (Petroleum) (OP) 27 Nov 17 18:40 Appreciate the feed back. Very helpful. Suspect operations will go a head with temp upgrade. I have discussed the related concerns about this. Going forward, any recommendation on how to monitor or quantify affects on auxiliary systems ie piping, supports etc.