Looking for 1950 API-ASME Code Allowable Stress
Looking for 1950 API-ASME Code Allowable Stress
(OP)
I need to find the allowable stress for SA-285-C at 950 and 1,000 degrees F from the API-ASME pressure vessel code that would have been applicable for a vessel built in 1950. Also if the thickness formula for cylindrical shells is different from the ASME code I would need that also.





RE: Looking for 1950 API-ASME Code Allowable Stress
950 F = 2600 psi
1000 F = 1350 psi
Shell: t=PR/(SE-.6P)
E= joint efficency for longitudinal joints
E= 1 for seamless shells
Heads: t=5PL/(6SE)
E=1 for seamless heads
Paragraph U-68, for complete radiograph, E=.95.
Paragraph U-69, otherwise (?) E=.8
Paragraph U-201(a), Vessels built to U-69, the allowable stress values may be multiplied by 1.25
......That's what I have.
RE: Looking for 1950 API-ASME Code Allowable Stress
What, exactly is this 60 year old pressure vessel doing at 1000 F ?
RE: Looking for 1950 API-ASME Code Allowable Stress
The process in the vessel operates at 950 F with some internal refractory lining. The client had some testing and replications done on the vessel metal which showed it to still be servicible. They have a new vessel on order but it will be some time before it is delivered and installed.
RE: Looking for 1950 API-ASME Code Allowable Stress
RE: Looking for 1950 API-ASME Code Allowable Stress
We're not making any recommendations, just supplying some information to them.
I've seen a few vessel such as this one that were built in the 1940's that are still operating at these elevated temperatures. Though it may or may not be prudent to do so, since the vessels were originally stamped for these design conditions before the code changes that lowered the service temperatures for carbon steel they are still in service at these temperatures.
RE: Looking for 1950 API-ASME Code Allowable Stress
Much of the research and metalographic studies on carbon steel exposed to high tempertures has been done after these vessels were put into service. After long periods above ~800F, the carbon precipitates out of the structure and causes failure
Some good information about this:
http://www.hghouston.com/index.html
RE: Looking for 1950 API-ASME Code Allowable Stress
RE: Looking for 1950 API-ASME Code Allowable Stress
RE: Looking for 1950 API-ASME Code Allowable Stress
RE: Looking for 1950 API-ASME Code Allowable Stress