API 650 - APPENDIX M - MAXIMUM OPERATING TEMPERATURE

[mancini]

I have worked in an API 650 tank design, carbon steel ASTM A 36 and the maximum normal fluid operation temperature is 194 F (90 C).

Is it a must to consider the appendix M from API 650 if the design temperature is 230 F (110 C)?

This design temperature, in our case, is not a usual temperature that can occur only in a process extreme condition, which is possible to occur only if there is a failure in other equipment's or if there is an operation mistake.

Thanks.

 

[JoeTank]

If you have an OPERATING temperature above 200F, Appendix M must be considered for the design of a new tank. If it will operate above 200 degrees at any time, you must consider it. The use of Appx M is currently based on operating temperatures, not design temperatures.

Steve Braune
Tank Industry Consultants

http://www.tankindustry.com

 

[mancini]

Thank you Steve, so I understand that it is correct to consider:

1) Maximum operation temperature the temperature that will occur on the normal operation condition and in this case is necessary to use Appendix M (usual operation condition).

But,

2) Design temperature: a process extreme condition, which is possible to occur only if there is a failure in other equipment's or if there is an operation mistake (not usual operation condition).

Thanks.

 

[JoeTank]

No, API-650 is not that specific. It uses the term "operating temperature". You have the priviledge of pondering whether the temperature excursions are considered as an operating condition. It really comes down to how hot the the shell gets. For example, the injection of a small amount of very hot fluid (>200F) into a large tank with cooler (<200F) may be an upset condition that does not raise the shell temp much. You get to worry about that when you specify the operating temp.

Steve Braune
Tank Industry Consultants

http://www.tankindustry.com

 

[JStephen]

Watch out for the possibility of boiling off large quantities of steam, which can overpower the venting system.