Temperature effect once the pressure change in API 620 tank

[engr.asad364]

This is in regards with the design temperature and pressure of API 620 tank which are mentioned Design 80C and 0.5 bar(g)
what maximum temperature which can be operated at atmospheric pressure. please advice
material of construction is A240 316L

 

[LittleInch]

80C

Temperature issues are independent of pressure.

Oh and this should be in the storage tank forum as this is not a Pressure vessel.....

 

[engr.asad364]

Thanks for response, actually it is pressurise tank that is why I post here, however I have checked that based on allowable it is giving the range of 115 c with same allowable stresses, so can consider 100c as safe. But there is a limitation of pressure as at atmospheric pressure shell plates failing and require more thickness

 

[Geoff13]

API 620 only permits 316L in Annex Q (cryogenic) and Annex R (low temperature). It seems very odd to be asking about high temperature limits for either of these Annexes. Are you considering a change of service?

If your calculations require greater shell thickness that implies you are using a higher SG product than the original design. This can alter other calculations, such as seismic.

API 620 is a storage tank code, as noted by LittleInch. Pressure vessels have greater than 1 bar(g) design.

 

[engr.asad364]

Not changing the service, but high temperature is expected during the chemical cleaning activity but at atmospheric pressure.

 

[GD2]

Thanks for response, actually it is pressurise tank that is why I post here, however I have checked that based on allowable it is giving the range of 115 c with same allowable stresses, so can consider 100c as safe. But there is a limitation of pressure as at atmospheric pressure shell plates failing and require more thickness

You see

This is in regards with the design temperature and pressure of API 620 tank which are mentioned Design 80C and 0.5 bar(g)
what maximum temperature which can be operated at atmospheric pressure. please advice
material of construction is A240 316L

Are you sure the material is 316 l and not 304L?
I am not sure how you have verified the wall thk at Atm@100C. The API 620 calculations are not the same as ASME Sec VIII.
API 620 uses explicit design methodology different than API 650. Are you using any design software?

API 620 tanks are designed to 120C and pressure up to 15 psig. Low temperatures designs are based on which Appendix had been used. By looking at the MOC, it appears Appendix Q for liquefied hydrocarbons.